KR20030068567A - Water-Responsive Biodegradable Polymer Compositions and Method of Making Same - Google Patents

Abstract

The present invention relates to a process for preparing hydrolyzable modified biodegradable polymers and hydrolyzable modifyable biodegradable polymers. In a preferred embodiment, the invention relates to a method of grafting polar groups on a biodegradable polymer and to modified biodegradable polymers produced by the method. The polymer composition is useful as a component in disposable articles that can be washed with water. Water sensitive polymer blends and methods of making such polymer blends are also disclosed.

Description

Water Responsive Biodegradable Polymer Compositions and Method of Making Same

Although the amount of plastics (hereinafter, polymers) used in various consumer goods, packaging materials and medical articles has not increased significantly in the last 20 years, it is a common recognition that more and more non-degradable plastics fill a limited landfill space. Despite these recognized shortcomings, polymers continue to be used in the manufacture of consumer goods, packaging materials and medical articles because plastic offers many advantages over other traditional materials, namely wood, glass, paper and metals. Advantages of using polymers include reduced manufacturing time and costs, improved mechanical and chemical properties, and reduced weight and shipping costs. It is the improved chemical resistance of most plastics that results in the non-decomposition of the plastics.

Disposal of waste materials, including food waste, packaging materials, and medical waste, into typical landfills provides a relatively stable environment in which these materials do not appear to degrade at detectable rates. Other waste disposal methods have been increasingly discussed and are being used to divert some of the landfill waste elsewhere. Examples of such alternatives include municipal solid waste composting, anaerobic digestion, enzyme digestion and wastewater sewage treatment.

There is much debate about the disposal of medical waste. Members of government agencies and the private sector are increasingly providing thorough scrutiny and funding for this plan. As generally accepted, concern about the end of contaminated material with infectious material is a definite and appropriate criterion to consider to ensure the safety of health care workers and the general public.

Currently, medical waste is classified as either recycled or disposable. The classification of whether a particular waste is recycled or disposable is usually determined by the materials that make up the article and the intended use of the article.

After use, recycled medical articles are cleaned and sterilized under strict conditions for reliable disinfection. In comparison, disposable medical articles are generally only used once. Nevertheless, the disposal procedure is not straightforward and often involves a number of steps for protection from potential hazards. Typically, disposable medical articles must be sterilized or sterilized after use, which adds significant costs before disposal in specially designated landfills or waste incinerators. As a result, the cost for disposal of contaminated disposable articles is quite high.

Despite the high disposal costs, disposable medical articles are desirable to ensure clean and uncontaminated equipment. Many times in medical situations, improperly performed sterilization procedures can have deleterious effects such as the transmission of infectious pathogens from one patient to another. Improper sterilization can also be fatal, for example, in laboratory settings where contaminated equipment can ruin experiments and lead to enormous time and financial losses.

Currently, disposable medical fabrics generally consist of thermoplastic fibers such as polyethylene, polypropylene, polyesters, polyamides and acrylics. These fabrics may also include mixtures of thermosetting fibers such as polyamides, polyarimids, and celluloses. They are typically 10 to 100 grams per square yard and can be formed by weaving, knitting or otherwise in a manner well known to those skilled in the textile arts, while at the same time by thermal bonding, tangling, wet-laying or needle punching. It can be formed into a nonwoven and can be formed into a film by blow extrusion or cast extrusion or solution casting. After use, these fabrics are difficult to dispose of, expensive and non-degradable.

The use of polymers for various disposable articles is universal and well known in the art. Indeed, the largest use of polymers in the form of films and fibers arises in the packaging and disposable article industries. Films used in the packaging industry include those used in plant and non-food packaging, commodity bags and trash bags. In the disposable article industry, the general use of polymers arises in the manufacture of diapers, personal care products, surgical drapes and hospital gowns, instrument pads, bandages and protective covers for various articles.

In view of eliminating landfill space and inadequate waste space, water-responsive polymers are desired. Currently, polymers such as polyethylene, polypropylene, polyethylene terephthalate, nylon, polystyrene, polyvinyl chloride and polyvinylidene chloride are preferred because of their excellent extrudability and film and fiber manufacturing properties, but these polymers are not water reactive. Moreover, these polymers are generally not composted and are undesirable from an environmental point of view.

Polymers and polymer blends that are generally considered to be water reactive have been developed. These are polymers known to have adequate properties to collapse when exposed to conditions causing composting. Examples of controversial water reactive polymers include starch biopolymers and polymers made of polyvinyl alcohol.

Materials made from these polymers have been used in films and fiber-containing articles, but many problems arise with their use. Polymers and articles made from such polymers are often not completely water reactive or fully composted. In addition, some water reactive polymers may also be excessively sensitive to water to limit the use of the polymer, or the polymer may require certain types of surface treatments that often render the polymer non-water-responsive. Other polymers are undesirable because of their poor heat resistance for universal use.

Personal care products, such as diapers, sanitary napkins, adult incontinence garments, and the like, generally consist of many different ingredients and materials. Such articles generally have some component, generally a back layer, composed of a liquid repellent or water barrier polymer material. Commonly used water barrier materials include polymeric materials such as polyethylene films or copolymers of ethylene and other polar and nonpolar monomers. The purpose of the water barrier layer is to minimize or prevent contamination of the user or adjacent clothing from leakage from the absorbent component during use. The water barrier layer also has the advantage of making the absorbent capacity of the product larger.

Such products are relatively inexpensive, hygienic and easy to use, but disposal of soiled products is not a problem. Typically, the soiled product is disposed of in a solid waste container. This increases the amount and cost of solid waste disposed of and is dangerous to the health of the person who may come in contact with the soiled product. Another ideal disposal method is to flush the soiled products in the bathroom using municipal sewage treatment systems and private residential septic tanks. Products suitable for disposal in sewage systems are said to be "flushable". It would be convenient to rinse such articles, but conventional materials do not disintegrate in water. This will clog the toilet and sewer pipes and call plumbers often. In municipal sewage treatment plants, liquid repellent material can clog the screens, causing them to shut down and cause sewage disposal problems. Thus, in such conventional products, it is undesirable but necessary to separate the barrier film material from the absorbent article prior to flushing.

In addition to the article itself, the packaging in which the disposable article is typically placed is also made of a water barrier, in particular a water resistant material. Water resistance is necessary to prevent the packaging material from degrading due to environmental conditions and to protect the disposable items therein. The packaging can be safely stored with other waste for commercial disposal, but especially for individual packaging of the product, it would be more convenient to dispose of the packaging in the bathroom with the disposable item being removed. However, when such a packaging material is made of a water resistant material, the above-described problem remains.

The use of lactic acid and lactide in water-stable polymers is well known in the medical industry. These polymers have been used in the past for the manufacture of water stable sutures, forceps, bone plates and biologically active controlled release devices. Methods developed for use of these polymers in the medical industry include techniques that meet the demand for high purity and biocompatibility in the final product. However, these methods are typically designed to produce small quantities of expensive products without much consideration of manufacturing costs and yields.

It is generally known that lactide polymers or poly (lactide) are unstable. However, the consequences of this instability have several aspects. One aspect is biodegradation or other forms of degradation that occur when lactide polymers or articles made from lactide polymers are discarded or composted after a period of use. Another aspect of this instability is the decomposition of the lactide polymer during processing at elevated temperatures, such as during melt processing by the end consumer purchaser of the polymer resin.

In the medical field, there is a marked need for polymers that are very stable and desirable for use in medical devices. This demand has historically been widespread in the high-volume, low-volume medical specialty products market, but is now equally widespread in the low-cost, high-volume medical market.

As described in US Pat. No. 5,472,518, compositions consisting of multilayered polymer films are known in the art. The utility of such structures is in the manipulation of physical properties to increase their stability or lifespan in the use of such structures. For example, US Pat. No. 4,826,493 describes the use of a thin layer of hydroxybutyrate polymer as a component of a multilayer structure as a barrier film for diaper components and an opening surgery bag.

Another example of a multilayer film is found in US Pat. No. 4,620,999, which describes the use of a water-soluble film coated with or laminated to a water-insoluble film as a disposable bag. The patent describes packaging materials for body secretions that are stable to body secretions during use, but can be degraded at a rate suitable for entry into the sewage system without clogging in the toilet by the addition of alkaline substances that achieve pH levels above 12. Such structures generally consist of a layer of polyvinyl alcohol film coated with polyhydroxybutyrate.

A similar waste treatment bag that can be disposed of in a flush toilet or sludge container is disclosed in Japanese Patent JP 61-42127. It consists of an inner layer of a water resistant polymer such as polylactide and an outer layer of a water-dispersible polymer such as polyvinyl alcohol. As disclosed in this patent, there are many examples of multilayer films used in disposable objects. Most of these examples consist of a film or fiber consisting of an inner layer of environmentally decomposable polymer and an outer layer of water reactive polymer. Typically, the inner layer consists of polycaprolactone or ethylene vinyl acetate and the outer layer consists of polyvinyl alcohol. However, these examples are all limited to compositions consisting of multiple layers of different polymers and do not include actual blends of different polymers.

Patent family EP EP 241178, Japanese patent JP 62-223112 and US Pat. No. 4,933,182 describe controlled release compositions for the treatment of periodontal disease. Controlled release compositions consist of a therapeutically effective agent in a carrier consisting of limited water soluble polymer particles dispersed in a water soluble polymer. Carriers of these inventions include the use of one or more polymers, but the disclosed carriers are not blends because limited water soluble polymers are incorporated in the water soluble polymers as particles having an average particle size of 1 to 500 microns.

The use of polymers for use in water reactive articles is disclosed in US Pat. Nos. 5,508,101, 5,567,510 and 5,472,518. This patent group discloses a series of water reactive compositions comprising hydrolytically degradable polymers and water soluble polymers. However, the composition of this group consists of articles consisting of polymers that are first formed into fibers or films and then combined. As such, the composition is substantially a mini-layer of individual films or fibers. Thus, even though the fibers and films of the polymers of the compositions have very close proximity to each other, they are not as intimate as the substantial polymer blends. In these compositions, the dispersion of one polymer in another is not considered nearly uniform since the individual polymers are essentially separate fibers or films.

US Pat. No. 5,525,671 to Evato et al. Discloses a process for preparing linear lactide copolymers from lactide monomers and hydroxyl group containing monomers. The polymer disclosed by Evato is a linear lactide copolymer prepared by reacting two monomers to form a linear polymer of block or random structure.

Polymer blend compositions for producing optimally blended fibers and films are preferred because they are very stable. Optimal blending of polymers means that the polymers are not copolymerized and are as closely linked as possible. Although individual polymer compositions that are physically blended are known, improved polymer blends in which the individual fibers are microscopically intimately bonded in the fibers and films result in a more stable, flexible, versatile, and most important use of the resulting composition. Preferably because of improved properties and performance.

In addition to the need for polymers that are highly stable and therefore suitable for normal use in most disposable articles, there is a simultaneous need for such polymer compositions to be water reactive. Thus, what is required is a material that can be used in disposable articles and is water reactive. Such materials should be versatile in use and low in production costs. The materials should be sufficiently stable for their intended use, but must be decomposed under the intended disposal conditions.

In addition, environmentally stable materials and coatings are increasingly being emphasized. These coatings reduce the use of solvent based coatings and increasingly rely on polar coatings such as water based materials. Uses of the graft copolymers of the present invention include, but are not limited to, materials having a greater affinity for polar coatings.

It is therefore an object of the present invention to provide a modified, hydrolytically biodegradable polymer.

Another object of the present invention is to provide a thermally processable polymer.

Another object of the present invention is to provide a commercially available polymer.

It is another object of the present invention to provide a thermally processable biodegradable polymer that is more compatible with polar polymers and other polar substrates or components.

It is another object of the present invention to provide a modified, hydrolytically biodegradable polymer useful for the manufacture of biodegradable articles that can be washed.

Another object of the present invention is to provide a modified, hydrolytically biodegradable polymer useful for preparing blends with improved mechanical and physical properties.

It is another object of the present invention to provide a modified biodegradable polymer with improved melt processability.

It is another object of the present invention to provide a polymer blend having a unique microstructure.

It is another object of the present invention to provide modified biodegradable polymers having improved compatibility in blends with polar polymers.

Another object of the present invention is to provide an improved polymer blend comprising poly (β-hydroxybutyrate-co-valerate), poly (butylene succinate) and / or polycaprolactone.

Summary of the Invention

The present invention discloses modified polymer compositions consisting of biodegradable polymers selected from poly (hydroxy alkanoates), poly (alkylene) succinates or polycaprolactones grafted with polar monomers, oligomers or polymers. The present invention relates to poly (β-hydroxybutyrate), poly (β-hydroxybutyrate-co-β-hydroxyvalerate, grafted with 2-hydroxyethyl methacrylate or poly (ethylene glycol) methacrylate And modified polymer compositions and compositions of polymers selected from poly (hydroxy alkanoates), poly (butylene succinates) and poly (alkylene succinates) such as poly (ethylene succinate), or polycaprolactones Described are extrusion methods for producing

Poly (β-hydroxybutyrate-co-valerate), poly (butylene succinate), poly (ethylene succinate) and polycaprolactone are commercially available and generally thermally processable biodegradable polymers. When the polar monomers are grafted to one or more of poly (β-hydroxybutyrate-co-valerate), poly (butylene succinate), and polycaprolactone, the resulting modified polymers are prepared for polar polymers and other polar substrates. More compatible. In the development of washable materials, the modified polymer compositions of the present invention have improved compatibility with water soluble polymers such as polyvinyl alcohol and polyethylene oxide than unmodified biodegradable polymers. The compatibility of the modified polymer compositions of the present invention with polar materials can be adjusted depending on the monomers selected, the grafting level and the blending process conditions. Adaptation of the compatibility of the blends with the modified polymer composition makes the resulting blends work better and improves the physical properties.

The water reactive composition disclosed herein has the unique advantage that the composition and the articles made from the composition are degraded by aerobic digestion in aeration tanks and in biomass by anaerobic digestion in an anaerobic digester in a wastewater treatment plant. Thus, articles made from the compositions of the present invention will not significantly increase the volume of sludge that accumulates in the wastewater treatment plant.

In another embodiment of the present invention, the present invention provides a water-sensitive homogeneous polymer blend composition comprising a biodegradable polymer and a water soluble polymer grafted with a polar monomer, oligomer or polymer or combination thereof.

In another embodiment of the present invention, the present invention relates to a first biodegradable polymer grafted with a polar monomer, oligomer or polymer or combination thereof and a second biodegradable grafted with polar monomer, oligomer or polymer or combination thereof. A novel polymer composition is provided comprising a blend of polymers, wherein the first and second biodegradable polymers are different polymers.

The present invention relates to modified, hydrolytically biodegradable polymers and methods of making modified hydrolytically biodegradable polymers. More specifically, the present invention relates to poly (hydroxy alkanoates), poly (alkylene succinates) or polycaprolactones modified by polar monomers and methods of modifying these polymers. In a preferred embodiment, the invention provides a method of grafting a polar functional group on a biodegradable polymer selected from poly (β-hydroxybutyrate-co-valerate), poly (butylene succinate) or polycaprolactone. To a grafted polymer composition produced by

1 is a graph of torque versus time during reactive extrusion of an embodiment of the present invention.

2 is a comparison of proton NMR spectra for unmodified PHBV and PHBV grafted with HEMA.

3 is a graph of apparent melt viscosity and rheology curves at various apparent shear rates of unmodified PHBV and the HEMA grafted PHBV of Example 1. FIG.

4 is a graph of DSC curves of PHBV and HEMA grafted PHBV.

FIG. 5 is a graph of torque vs. time during reactive extrusion of two PEG-MA grafted PBS samples of Example 2. FIG.

6 is a comparison of proton NMR spectra for grafted PBS and unmodified PBS from reactive extrusion on the Haake extruder of Example 2. FIG.

FIG. 7 is a graph of melt rheological curves for PBS and unmodified PBS grafted with PEG-MA on the Hake Extruder of Example 2. FIG.

8 is a graph of melt rheological curves for PBS and unmodified PBS grafted with HEMA on the ZSK-30 extruder of Example 2. FIG.

9 is a graph of DSC curves for PBS and unmodified PBS grafted with PEG-MA of Example 2. FIG.

FIG. 10 is a graph of DSC curves for HEMA grafted PBS and ungrafted PBS of Example 2. FIG.

FIG. 11 is a SEM (scanning electron microscope) image of the topological morphology of the fracture surface of a film made from a 60/40 blend of PBS / PEO showing a two-phase microstructure.

12 is an SEM image of the topological morphology of the fracture surface of a film made from a 60/40 blend of grafted PBS / grafted PEO, showing biphasic microstructure and improved compatibility.

FIG. 13 is an SEM image of the topological morphology of the fracture surface of a film made from a 60/40 blend of PBS / PEO, showing biphasic microstructure using BEI (back-scattering electrophotography).

FIG. 14 is an SEM image of the topological morphology of the fracture surface of a film made from a 60/40 blend of grafted PBS / grafted PEO with no visible PEO phase using BEI (back-scattering electrophotography).

FIG. 15 is a graph of the DSC analysis of the PBS / PEO blend showing that the T _m on the PEO of the PBS / PEO reactive blend decreases with increasing% PEO in the blend.

FIG. 16 is a graph of DSC analysis of a PBS / PEO blend showing that the amount of change (ΔT _m ) of T _m on the PEO of the reactive blend increases relative to the physical blend as% PEO in the blend increases.

FIG. 17 is a graph of DSC analysis of PBS / PEO blends showing a comparison between the DSC curves for the physical and reactive blends of 30/70 PBS / PEO.

FIG. 18 is a graph of melt rheology curves of physical and reactive blends of 20/80 and 60/40 PBS / PEO and melt rheology curves of PBS alone.

The present invention includes biodegradable polymers modified by graft polymerization with polar monomers, oligomers or polymers. The present invention also provides a blend of a biodegradable polymer modified by graft polymerization with a polar monomer, oligomer or polymer with a water sensitive polymer or another biodegradable polymer modified by graft polymerization with a polar monomer, oligomer or polymer. It includes a polymer composition comprising. The resulting polymer composition can be made from films, fibers, coatings, beads, powders, and the like, and can be fabrics, garments and articles, such as diapers, towels, coatings, outer wraps, gowns, head coverings, face masks, shoes It can be used to make covers, CSR wraps, sponges, dressings, tapes, underpads, liners, laundry cloths, sheets, pillowcases, napkins, cloth-like outer covers, surgical products, and wound care products. The invention also relates to biodegradable personal hygiene products such as diapers, training pants, female tampons, pads and pantyliners and barrier films for them, adult incontinence products, wet wipes and / or wipes and weaving, Particularly suitable for use in nonwoven or otherwise formed materials. These products can be used in both hospital and outpatient facilities and home environments in the medical industry.

Biodegradable polymers useful in the present invention include hydrolyzable, poly (β-hydroxybutyrate) (“PHB”), poly (β-hydroxybutyrate-co-β-hydroxyvalerate) (“PHBV Poly (alkylene) such as poly (β-hydroxy alkanoate) (“PHA”), poly (ethylene succinate) (“PES”) and poly (butylene succinate) (“PBS”) such as Succinate) (“PAS”), and polycaprolactone (“PCL”). In certain embodiments of the invention, polylactide (“PLA”) is useful as a biodegradable polymer.

Poly (β- hydroxybutyrate-co -β- hydroxy valerate) ( "PHBV") resins are microorganisms, for example Alcaligenes oil Trojan crispus fermentation of carbohydrate and an organic acid by (Alcaligenes eutrophus), or By the use of transgenic plants ["Biodegradable Plastics from Plants," CHEMTECH, September 1996, ppgs. 38-44]. PHBV is a biodegradable polymer and has the following chemical structure.

The molecular weight of PHBV useful in the present invention is not critical to the present invention and may generally be about 20,000 to 2,000,000 grams per mole. The PHBV compositions described in the examples below were prepared using PHBV grades purchased under the trade name Biopol® D600G from Zenca Bio-Products, Wilmington, Delaware, USA. PHBV purchased from Geneca Bio-Products is biodegradable. Any PHBV can be selected for use in the present invention, and the molecular weight of the PHBV can vary depending on the desired properties and uses.

Polyalkylene succinate ("PAS") resins are produced by various synthetic methods, for example as reaction products of aliphatic dicarboxylic acids and ethylene glycol or butylene glycol. Poly (butylene) succinate (“PBS”) is commercially available from Showa Highpolymer Company (Tokyo, Japan) under the trade name Bioolle®. PBS is a biodegradable polymer and has the following chemical structure.

The molecular weight of the PAS useful in the present invention is not critical to the present invention and may generally be about 20,000 to 2,000,000 grams per mole. The PBS compositions described in the examples below were prepared using Bionol® 1020 or 1040 grade PBS purchased from Showa High Polymer Company. Any PAS may be selected for use in the present invention, and the molecular weight of the PAS may vary depending on the desired properties and uses.

Polycaprolactone ("PCL") resins are produced by various synthetic methods, for example by ring-opening polymerization of ε-caprolactone. An example of a commercial polycaprolactone is a biodegradable polymer commercially available from Union Carbide Corporation (Danbury, Connecticut, USA) under the trade name Ton, and having the following chemical structure.

The molecular weight of PCL useful in the present invention is not critical to the present invention and may generally be about 50,000 to 1,000,000 grams per mole. The PCL compositions described in the examples below were prepared using P-767 and P-787 PCL purchased from Union Carbide Corporation (Danbury, Connecticut, USA) (Ton® Polymer Catalog No. UC-261) . PCL purchased from Union Carbide Corporation is biodegradable, melt flow is 1.9 ± 0.3 g / min (80 ° C, 44 psi, ASTM 1238-73) for P-767, 1.0 ± 0.2 g / min (125 ° C, 44 psi). Any PCL may be selected for use in the present invention, and the molecular weight of the PCL may vary depending on the desired properties and uses.

The polar monomers, oligomers or polymers useful in the present invention contain polar functional groups such as hydroxyl, carboxyl, halo-, glycidyl, cyano, amino, carbonyl, thiol, sulfonic, sulfonate, etc. suitable for the present invention. And ethylenically unsaturated monomers are included. Examples of polar vinyl monomers useful in the present invention include poly (ethylene glycol) acrylates, poly (ethylene glycol) alkyl ether acrylates, poly (ethylene glycol) methacrylates, poly (ethylene glycol) alkyl ether methacrylates, acrylic resins. , Maleic anhydride, itaconic acid, sodium acrylate, 3-hydroxypropyl methacrylate, 2-hydroxyethyl methacrylate, 3-hydroxypropyl acrylate, 2-hydroxyethyl acrylate, acrylamide, 2 Bromine ethyl methacrylate, 2-chloroethyl methacrylate, 2-iodoethyl methacrylate, 2-bromoethyl acrylate, 2-chloroethyl acrylate, 2-iodoethyl acrylate, glycidyl Methacrylate, 2-cyanoethyl acrylate, glycidyl acrylate, 4-nitrophenyl acrylate, pentabromophenyl acrylate, poly (prop Ethylene glycol) methacrylate, poly (propylene glycol) acrylate, 2-propene-1-sulfonic acid and its sodium salt, 2-sulfoethyl acrylate 2-sulfoethyl methacrylate, 3-sulfopropyl acrylate, 3 Sulfopropyl methacrylates or mixtures thereof, including but not limited to. Preferred ethylenically unsaturated monomers containing polar functional groups include 2-hydroxyethyl methacrylate (HEMA) and poly (ethylene glycol) methacrylate (PEG-MA). As expected, a wide range of polar vinyl monomers can impart polar functionality to biodegradable polymers and can be effective monomers for grafting.

The grafted biodegradable polymer may contain about 1 to 20 weight percent of the grafted polar monomer, oligomer or polymer. Preferably, the grafted biodegradable polymer contains about 2.5 to 20 weight percent of the grafted polar monomer, oligomer or polymer, and most preferably about 2.5 to 10 weight percent of the grafted polar monomer, oligomer or polymer. It contains.

HEMA (Aldrich Cat. No. 12,863-8) and PEG-MA (Aldrich Cat. No. 40,954-5) used in the examples were all purchased from Aldrich Chemical Company. PEG-MA, purchased from Aldrich Chemical Company, was a poly (ethylene glycol) ethyl ether methacrylate having a number average molecular weight of about 246 grams per mole. Analogs of HEMA and PEG-MA are also useful in the present invention. Analogs of HEMA include, for example, 3-hydroxypropyl methacrylate and 4-hydroxybutyl methacrylate, and analogs of PEG-MA have molecular weights ranging from about 200 g / mol to about 10,000 g / mol Have

Methods of making grafted biodegradable polymer compositions have been described as reactive-extrusion processes. The grafting reaction also achieves the necessary mixing of the biodegradable polymer with the polar monomers and any other reactive components and produces sufficient energy to carry out the grafting reaction, for example by generating free radicals to initiate the grafting reaction process. It can also be done in other reactors as long as it is fed. The reaction is preferably carried out in the polymer melt phase, ie in the absence of bulk solvent. This is a very effective process since no solvent removal step is required in the process.

Other reactive components that may be added to the compositions of the present invention include initiators such as Elf Atochem North America, Inc. Lupersol 101, a liquid organic peroxide available from Elf Atochem North America, Inc., Philadelphia, PA, USA. Free radical initiators useful in the practice of the present invention include acyl peroxides such as benzoyl peroxide; Dialkyl, diaryl, or aralkyl peroxides such as di-t-butyl peroxide; Dicumyl peroxide; Cumyl butyl peroxide; 1,1-di-t-butyl peroxy-3,5,5-trimethylcyclohexane; 2,5-dimethyl-2,5-di (t-butylperoxy) hexane; 2,5-dimethyl-2,5-bis- (t-butylperoxy) hexin-3 and bis (a-t-butyl peroxyisopropylbenzene); Peroxyesters such as t-butyl peroxypivalate; t-butyl peroctoate; t-butyl perbenzoate; 2,5-dimethylhexyl-2,5-di (perbenzoate); t-butyl di (perphthalate); Dialkyl peroxymonocarbonates and peroxydicarbonates; Hydroperoxides such as t-butyl hydroperoxide, p-methane hydroperoxide, evacuation hydroperoxide and cumene hydroperoxide and ketone peroxides such as cyclohexanone peroxide and methyl ethyl ketone peroxide Included. Azo compounds such as azobisisobutyronitrile can also be used.

The amount of free radical initiator in the total mixed composition comprising the biodegradable polymer and / or the water soluble polymer and the polar monomer or polar vinyl monomer mixture ranges from about 0.1 to about 1.5 weight percent. If the amount of free radical initiator is too low, there will not be enough initiator present to initiate the grafting reaction. If the amount of free radical initiator is too high, undesirable crosslinking of the polymer composition will occur. Crosslinked polymers are not preferred in the present invention because they cannot be processed into films, fibers or other useful products.

In addition, other components known in the art may be added to the graft polymer of the present invention to further improve the properties of the final material. For example, polyethylene glycol may be further added to reduce melt viscosity to improve melt flow. Other types of additives may also be incorporated to provide the desired special properties. For example, antistatic agents, pigments, colorants and the like can be incorporated into the polymer composition. In addition, lubricants or slip agents may be incorporated into the blends made from the polymers of the present invention to improve processing properties. All of these additives are generally used in relatively small amounts, usually less than 3% by weight of the final composition.

The biodegradable polymers and polar monomers, oligomers or mixtures of polymers can be mixed, compounded, processed or made into a suitable mixing device, such as a Brabender Plasticorder, roll mill, single- or multi-screw extruder, or polymer Mechanical deformation in any other mechanical mixing device that can be used to. Particularly preferred reactors are extruders with one or more ports. In a preferred embodiment, the reaction apparatus is a co-rotating two-axis extruder, for example a ZSK-30 two-axis compounding extruder manufactured by Warner & Pfleiderer Corporation (Lamsey, NJ). to be. This extruder allows for a large number of supply and exhaust ports and provides the high strength dispersion and distribution mixing necessary to produce grafted biodegradable polymers of uniform composition and homogeneously distributed grafted side chains derived from polar vinyl monomers. to provide.

In another embodiment of the invention, the invention relates to a first biodegradable polymer grafted with a polar monomer, oligomer or polymer or combinations thereof and a second biodegradable polymer grafted with a polar monomer, oligomer or polymer or combinations thereof. A novel polymer composition is provided, wherein the first and second biodegradable polymers are different polymers. The ratio of the two biodegradable polymers useful in the present invention is about 1:99 to 99: 1 by weight. Preferred first and second biodegradable polymers in embodiments of the invention are modified polylactide and modified PHBV. The amount of grafting monomer of one of the modified biodegradable polymers is about 1 to 20% by weight of the starting biodegradable polymer or ungrafted biodegradable polymer.

As disclosed herein, PHBV has a very slow cooling rate, so this material is not practical for commercial use. In addition, as disclosed herein, PLA is too brittle for the applications disclosed herein. However, while PLA or PHBV alone is unsuitable for such applications, the blend of PLA and PHBV allows the PHBV to cool at an acceptable rate and also makes the PLA more flexible so that these materials can be used in the products disclosed herein. Was unexpectedly discovered.

In another embodiment of the present invention, a blend of the modified biodegradable polymer and water soluble polymer of the present invention can be prepared. Such blends exhibit increased water sensitivity of the composition, which increases the exposed surface area of the biodegradable polymer after dissolution of the water soluble component, thereby promoting the rate of hydrolytic degradation of the biodegradable polymer. Water soluble polymers that can be blended with the modified biodegradable polymers of the present invention include polyethylene oxide, polyvinyl alcohol, hydroxypropyl cellulose, polyacrylamide, sulfonated polyester and polyacrylic acid. The weight fraction of the modified biodegradable polymer in the blend is in the range of 1 to 99% by weight. This fraction determines the water reactivity of the blend. A wide range of water reactivity includes water dispersible, water-disintegratable, water-weakenable and water-stable, and these terms are defined below.

Biodegradable polymers or modified biodegradable polymers present in the blends used to make the fibers, films or other shapes reduce the water sensitivity of the purely water soluble polymers used, such as polyvinyl alcohol (“PVOH”). Biodegradable polymers grafted with polar monomers or mixtures of monomers are preferred for improving compatibility with highly polar water-soluble polymers, for example PVOH, to obtain good processing, mechanical and physical properties. Blends can be used to make shapes other than fibers or films, and the blends can be thermoformed into complex shapes.

As used herein, the term "water dispersible" means that the composition is immersed in water for about 5 minutes and then dissolved or broken into pieces smaller than the opening of a 20 mesh screen. The term "water disintegratable" means that the composition breaks down into a number of pieces within 5 minutes when immersed in water, and some pieces are filtered by a 20 mesh screen without leaving the thread as it exits through the pinhole. The term "water weakness" means that the composition is soaked in water for 5 minutes and then remains in one piece, but weakens to lose stiffness and become drape. That is, the composition is bent even if no external force is applied to the composition when one side is fixed in the horizontal position. The term "water stability" means that the composition is not drape after 5 minutes of soaking in water and remains in one piece after the water reaction test.

As used herein, the term "graft copolymer" is produced by a combination of two or more chains having constitutively or morphologically different characteristics, one of the chains functioning as a backbone backbone, and one or more of the chains By copolymer is meant a copolymer that is joined at several point (s) along the backbone to form a side chain. The molar amount of grafted monomers, oligomers or polymers, ie side chain species, may vary, but must be greater than the molar amount of the parent species. The term "grafted" means that a copolymer has been produced comprising side chains or species bound at some point (s) along the backbone of the parent polymer. The term "blend" as applied to a polymer means an intimate blend of two or more polymer chains having constitutively or morphologically different characteristics that are not bonded to one another. Such blends may be homogeneous or heterogeneous (see Sperling, L. H., Introduction to Physical Polymer Science, 1986, pp. 44-47, which is incorporated herein by reference). Preferably, the blend is produced by blending two or more polymers at temperatures above the melting point of each polymer.

There are several ways to make the modified biodegradable polymers of the present invention. One method is a solvent-based grafting method in which a biodegradable polymer is dissolved in a solvent, to which a desired amount of free radical initiator and a polar monomer or a mixture of two or more polar monomers are added, in particular a polar vinyl monomer. After sufficient grafting, the solution is purified and the solvent and unreacted monomers are removed to produce the grafted biodegradable polymer. This method is relatively more labor intensive and expensive compared to the melt grafting method described below.

Another method is based on a melt phase reaction in which the molten biodegradable polymer is reacted with a free radical initiator and a polar monomer or a mixture of two or more polar monomers, in particular polar vinyl monomers. Melt phase reforming is referred to as "reactive extrusion" because new polymeric species is produced after the reforming reaction. There are several specific methods for carrying out the grafting reforming reaction in the melt. In a first method, all components, including a proportion of the biodegradable polymer, the free radical initiator and a mixture of polar monomers or a mixture of polar monomers, are added simultaneously to the melt mixing apparatus or the extruder. In a second method, the biodegradable polymer is fed into a feed zone of a two-screw extruder and then melted, a free radical initiator and a mixture of polar monomers or polar monomers are injected under pressure into the biodegradable polymer melt and then the resulting melt mixture Can be reacted. In a third method, the biodegradable polymer is fed to the feed zone of a two-screw extruder and then the free radical initiator and the polar monomer or mixture of monomers are fed independently to the two-screw extruder at different points along the length of the extruder. Heated extruder extrusion is performed under high shear and strong dispersion and distribution mixing to produce highly uniform grafted biodegradable polymers.

Hydrolytically degradable and water soluble polymer blend compositions according to the present invention are prepared by melt blending processes. It is preferred to blend or mix the two components according to the invention under suitable temperature and shear / pressure conditions to ensure mixing in an extruder, for example a single-screw extruder or a two-screw extruder. The blending process may also be carried out in a batch mixing device, for example a melt mixer or kneader. Modified biodegradable polymers or water soluble polymers such as polyvinyl alcohol (“PVOH”) can be fed into the extruder / mixer simultaneously or sequentially.

The present invention relates to PHA, PHB, PHBV, PAS, PES, graft polymerized with HEMA or PEG-MA, blended with a blend of modified biodegradable polymers and water soluble polymers, e.g. An optionally water reactive homogeneous polymer blend composition comprising a modified biodegradable polymer such as PBS or PCL is disclosed. As used herein, the term “homogeneous polymer blend composition” means that the polymer blend forms a coherent continuous phase structure of modified biodegradable polymers and water soluble polymers, such as polyvinyl alcohol, that are macrohomogeneous. Microscopically, the size of the dispersed phase is several microns or less. Homogeneous polymer blend compositions are prepared by mixing modified biodegradable polymers and water soluble polymers, such as polyvinyl alcohol, at temperatures above the melting point of the polymer with the highest melting point and below the decomposition point of the polymer with the lowest melting point (solid form, eg Prior to cooling into a film or fiber). For homogeneous polymer blend compositions of polylactide and polyvinyl alcohol, the polymer with higher melting point is polyvinyl alcohol and the polymer with lower decomposition point is also polyvinyl alcohol. The melting point of polyvinyl alcohol is generally about 180 to 190 ° C, more specifically about 183 ° C. The decomposition point of polyvinyl alcohol is about 210 ° C. The resulting composition is, for example, like islands of PHBV grafted with HEMA in a sea of polyvinyl alcohol, and at microscopic levels the HEMA grafted PHBV appears to be nearly uniformly distributed in polyvinyl alcohol. Thus, the homogeneous polymer blend composition of the present invention has graft modified biodegradable polymer islands of average size of about 0.3 to less than 0.4 microns that are very finely dispersed within the water soluble polymer.

In terms of uniformity of dispersion, the "polymer blend" of the present invention is distinguished from the "blended polymer". The compositions of the present invention have a melting point higher than the melting point of the polymer having the highest melting point (e.g., greater than 183 ° C for polyvinyl alcohol) and having a decomposition point of the lowest melting point (e.g. 210 ° C for polyvinyl alcohol). Polymers blended at lower temperatures at high shear, ie, shear rates of at least 100 seconds ⁻¹ . Thus, a homogeneous polymer blend composition is formed before the polymer is molded into a film or fiber, resulting in a composition of highly interconnected and intimately interconnected polymers, optionally uniformly dispersed. The composition is distinguished from a composition comprising a blended polymer consisting of a polymer which, after being molded into a fiber or film, is blended to produce a composition that is hardly uniformly dispersed and often appears as individual polymers layered or mixed together. In summary, when individual polymers are blended under high mechanical shear at temperatures above the melting point of the polymer with the highest melting point and below the decomposition point of the polymer with the lowest melting point, a nearly uniformly distributed and dispersed polymer is produced. In contrast, when the individual polymers are mixed according to standard methods, a blended polymer composition is produced in which the polymers are not united together.

The water sensitivity of the polymer composition can be adjusted according to the degree of homogeneity of the polymer blend. Mixing, shearing, extrusion and other blending techniques, and the relative proportions of the polymer resins used, can be manipulated to determine the microstructure of the polymer composition. The “microstructure” of a polymer blend specifically refers to the size and distribution of, for example, graft modified biodegradable polymer islands within the water soluble polymer sea. The size of the islands can vary from about 0.1 to 5.0 μm. Generally, as the sizes of the islands increase and / or the distance between the islands decreases, the composition increases in wet machine strength and loses flexibility in water. For example, for water dispersible compositions, the islands are typically small (about 0.2-1.0 μm) and distributed away from each other. In the case of a water disintegratable composition, the islands are closer to each other and even some islands may be connected to each other. In the case of a water-vulnerable composition, the islands are in close proximity and many of them appear as huge masses.

The method of making the film of the present invention affects the morphology of the film. In order to form a finely dispersed film of a graft modified biodegradable polymer of spherical, nearly spherical or elliptical particles, it is preferred to form the film using an unoriented method. One non-oriented method for producing the film is thermomechanical compression. Examples of thermomechanical compressions are described in the examples below. Manufacturing methods for orienting the film, such as extrusion or blowing of the film, produce a film having a morphology containing the graft modified biodegradable polymer in which the dispersed phase extends into the continuous phase entire fibrous structure of the water soluble polymer. Oriented films have reduced water reactivity and do not disperse in cold water, only cold water weakening or cold water disintegrating. The present invention provides improved compositions and methods of making compositions having improved morphology and cold water reactivity.

One embodiment of the invention is a water dispersible homogeneous polymer blend composition comprising from about 1 to about 35 weight percent of a graft modified biodegradable polymer and from about 65 to about 99 weight percent of a water soluble polymer. The composition is characterized by a morphology in which fine graft modified biodegradable polymer particles are dispersed in a continuous phase of the water soluble polymer. As used herein, the term “water dispersible” means that the composition dissolves or breaks into pieces smaller than 20 mesh after testing with water for 2 minutes at room temperature (18-22 ° C.). As used herein, “test with water” refers to preparing a sample of a composition, immersing it in a scintillation vial filled with water for 5 minutes, and then shaking the vial for about 30 seconds in a mechanical shaker, This means emptying the contents of the vial through a standard 20 mesh screen.

Another embodiment of the invention is a water disintegratable homogeneous polymer blend composition comprising about 35 to about 45 weight percent of a graft modified biodegradable polymer and about 65 to about 55 weight percent of a water soluble polymer. This composition also features a morphology in which fine graft modified biodegradable polymer particles are dispersed in a continuous phase of the water soluble polymer. The size of the modified biodegradable polymer domain is larger than that domain in the water dispersible composition. As used herein, the term “water disintegratable” means that the composition breaks into a number of pieces after 2 minutes, and a portion of the composition piece is filtered over a 20 mesh screen.

Another embodiment of the invention is a water weakenable composition comprising about 45 to about 55 weight percent graft modified biodegradable polymer and about 55 to about 45 weight percent water soluble polymer. The composition is characterized by a morphology in which fine graft modified biodegradable polymer particles are dispersed in a continuous phase of the water soluble polymer. The domain size of the modified biodegradable polymer is slightly larger than in water disintegratable compositions. As used herein, the term "water weakness" means that the composition remains in one piece after 5 minutes, but is weakened, loses stiffness, and becomes drape, i.e. bend without the external force applied when a corner is held in a horizontal position. It means losing. As used herein, the term "water stability" means that the composition is not drape and remains in one piece after testing with water.

To prepare an optionally water dispersible composition, about 1 to 35% of the graft modified biodegradable polymer and about 65 to 99% of the water soluble polymer are blended. To prepare a composition that is optionally water disintegratable, about 35 to 45% of the graft modified biodegradable polymer and about 65 to 55% of the water soluble polymer are combined. To prepare a composition that is optionally water weak, about 45 to 55% of the graft modified biodegradable polymer and about 55 to 45% of the water soluble polymer are combined. To prepare an optionally water stable composition, about 55-99% graft modified biodegradable polymer and about 45-1% water soluble polymer are blended.

In another embodiment of the invention, the invention provides grafted water soluble polymers such as grafted PEO or grafted PVOH with grafted PHBV, grafted poly (alkylene succinate) and grafted polycapro A reactive polymer blend composition of grafted biodegradable polymers such as lactones is disclosed. The ratio of grafted water soluble polymer to grafted biodegradable polymer in the blend of the present invention is about 1:99 to 99: 1 by weight. Examples of the amount of the grafting monomer, the free radical initiator for the grafting reaction and the free radical initiator for the grafting reaction are given in the grafted polymer described above for the total weight of the grafting monomer, biodegradable polymer and water soluble polymer. Same as did.

The processing properties of the polymer blend for the film can be improved by the optional incorporation of lubricants or slippers into the blend. Such lubricants are well known in the art and are available from Union Carbide Corporation (Danbury, Connecticut, USA), TWEEN 20, TURGITOL® NP 13 and various fatty acids and Fatty acid derivatives such as KENAMIDE® E available from Witco Chemical, USA. The blend may also contain other ingredients to enhance the properties of the resulting material. For example, polyethylene glycol can be added to lower the melt viscosity of the melted blend to a range suitable for other processes such as meltblown processes or melt spray nonwoven fabrication processes. Suitable polyethylene glycols are available from Union Carbide under the trade name CARBOWAX®.

Polymer blending is an important aspect of the preparation of the compositions of the present invention. Depending on the parameters selected, such as blending technique, temperature profile and pressure application, the final water response properties of the composition may be affected.

The invention is illustrated in more detail by the following specific examples. It is to be understood that these examples are exemplary embodiments and that the present invention should not be limited by the examples or the description. Rather, the claims appended hereto are to be understood broadly within the scope and spirit of the invention.

<Example 1>

Reactive Extrusion of PHBV Using HEMA and PEG-MA

The reactive extrusion chemistry for PHBV grafting is shown below.

Reactive Extrusion Chemistry for Grafting Poly (β-hydroxybutyrate-co-valerate)

Is

Mixture of

To produce a mixture.

Reactive extrusion process

The grafted PHBV was prepared using a counter-rotating two-axis extruder manufactured by Haake, Paramus, NJ. The extruder had two conical shafts 30 mm at the feed port and 20 mm at the die. The shaft length was 300 mm. Supply PHBV resin (Beneca Bio-Products' BioPol® P600G) to the supply port and supply both HEMA monomer and Lupersol® 101 to the supply port with an Eldex pump. It was. The die used to extrude the modified PHBV strand had two openings 3 mm in diameter spaced 5 mm apart. The modified PHBV strands were cooled in a water bath. Unlike polylactide ("PLA"), PHBV showed very slow solidification after initial cooling in water. In fact, the polymer strands could not be cooled fast enough to be pelleted even in ice water (about 0 ° C.). Interestingly, the grafted PHBV showed elastomeric properties in the melt. The strand could be easily stretched and shrunk to its initial length. This material property was not observed in grafted PLA or grafted polyolefin. After solidification, the grafted PHBV strands were very rigid and brittle. Solidification of both the unmodified PHBV and the grafted PHBV took several minutes to complete, so that the polymer sample was recovered in small chunks, solidified overnight and then chopped into small pieces.

PHBV was fed to the extruder at a throughput of 5.0 pounds per hour using a volumetric feeder. HEMA and peroxide were injected into the extruder at throughputs of 0.25 pounds per hour and 0.020 pounds per hour, respectively. In one experiment, the axial speed was 150 rpm.

Two grafted PHBV samples were generated on a Hake extruder. Table 1 below shows the process conditions for reactive extrusion of PHBV and HEMA on a Hake extruder.

The torque on the Hake extruder was monitored during each reactive extrusion. 1 is a plot of torque versus time during reactive extrusion. At the beginning of the reaction, it was observed that the torque decreased significantly when HEMA and peroxide were added. When the torque stabilized, a PHBV sample grafted with HEMA was collected. When the chemical pump was stopped and the reactive extrusion completed, the torque increased to approximately the torque level before the reactive extrusion began. The change in torque observed during the experiment indicated a modification of the polymer and enabled effective monitoring of the reactive extrusion process. No visual difference was observed between the extruded molten strand of unmodified PHBV and the grafted PHBV.

2 compares the proton NMR spectra of unmodified PHBV and HEMA grafted PHBV. A characteristic peak (CH ₃ ) of HEMA monomer was observed at 2.0 ppm. This confirmed the modification of PHBV but failed to quantify the amount of HEMA grafted onto PHBV.

Melt rheological experiments for modified and unmodified PHBV were performed on a Goerttfert Rheograph 2000 available from Goettfert, Rock Hill, SC. The modified PHBV of this example was prepared using 9 wt% HEMA and 0.45 wt% lupersol®. Weight percentages of HEMA and lupersol® are based on the weight of PHBV.

Melt rheological tests were performed using a 30/1 (length / diameter) mm / mm die at 180 ° C. Apparent melt viscosity was measured at apparent shear rates of 50, 100, 200, 500, 1000 and 2000 1 / sec.

Apparent melt viscosity at various apparent shear rates was plotted and the rheological curves for the unmodified PHBV and HEMA grafted PHBV of the above examples were generated as shown in FIG. 3. The results show that the unmodified PHBV has a higher melt viscosity than the HEMA grafted PHBV over the entire shear rate range. The decrease in melt viscosity was indicative of the chemical modification of PHBV due to reactive extrusion with HEMA.

Table 2 shows the data of different differential scanning calorimetry (“DSC”) analyzes of PHBV and HEMA grafted PHBV samples.

For PHBV samples grafted with HEMA, it was observed that both melt peak and melt enthalpy were reduced compared to unmodified PHBV. Changes in the observed thermal properties were indicative of modified crystalline structure and indirect indices of HEMA grafting. In conventional reactive extrusion operations, melt peaks and melt enthalpy have also been observed to decrease with HEMA grafted polyethylene.

4 shows a comparison of DSC curves of PHBV and HEMA grafted PHBV. Both curves show two characteristic melting peaks. The curve shows that the melt peak and melt enthalpy of the HEMA grafted PHBV were reduced compared to the unmodified PHBV. In addition to the reduction of the melt peaks, the two melt peaks were more separated in the grafted PHBV sample. In addition, the relative ratio of hot melt peak to cold melt peak increased substantially after grafting, indicating that the properties of the two types of crystalline size changed.

<Example 2>

Reactive Extrusion of PBS and HEMA

In both the Hake extruder and ZSK-3 extruder described in Example 1, a reactive extrusion process for grafting PBS was carried out in two different grades of PBS, Bionol® 1040 and Bionol® 1020. It was carried out using. The ZSK-30 extruder was a idle two-screw extruder manufactured by Warner & Flyderer Corporation (New Jersey, USA). The diameter of the extruder was 30 mm. The length of the shaft was 1388 mm. This extruder had 14 barrels numbered sequentially from 1 to 14 from the feed hopper to the die. The first barrel, ie barrel # 1, received PBS and was cooled with water without heating. HEMA, a vinyl monomer, was injected into barrel # 5, and Lutosol® 101 peroxide from Atochem was injected into barrel # 6. Both monomers and peroxides were injected through a pressure nozzle injector. A vacuum port for devolatilization was included in barrel # 11.

The reactive extrusion of PBS differed significantly from the reactive extrusion of PLA, PHBV or polyolefins. Indeed, significant differences were observed between the reactive extrusion of two different grades of PBS in different extruders.

The reactive extrusion chemistry of PBS grafting is shown below.

Reactive Extrusion Chemistry for Grafting Poly (Butylene) Succinate

silver

Mixture of

To produce a mixture.

First, extrusion conditions were determined for reactive extrusion of Bionol® 1040 on a Hake extruder. This polymer behaved very differently from PLA or PHBV. Indeed, the properties of the molten and solid states appear to be very good, indicating that they are more similar to polyolefins. Two PEG-MA grafted Bionol® 1040 samples were generated on a Hake extruder. Table 3 below shows the reactive extrusion process conditions for PEG-MA grafted Bionol® 1040 experiments on a Hake extruder.

Torque on the Hake extruder was monitored during reactive extrusion of PEG-MA and Bionol® 1040. 5 shows a plot of torque versus time during reactive extrusion of both PEG-MA grafted Bionol® 1040 samples. At the beginning of the reaction, torque was observed to be significantly reduced when 4.6% PEG-MA and 0.29% peroxide were added. When the average torque reached steady state, the reaction product was determined to be stabilized and samples were collected. When the chemical pump was stopped and the reactive extrusion completed, the torque increased to the torque level before reforming. The same phenomenon was observed for 8.9% PEG-MA and 0.46% lupersol® 101 peroxide. A Bionol® 1040 sample grafted with PEG-MA was shown to have a lower viscosity on the extruded melt strand. No noticeable gel was observed, and the solids properties of the strands were found to be similar to unmodified Bionol 1040.

Subsequently, extrusion conditions for the Bionol® 1020 reactive extrusion on the ZSK-30 extruder were determined. Unmodified Bionol® 1020 behaved similarly to Unmodified Bionol® 1040 on a Hake extruder. Four HEMA grafted Bionol® 1020 samples were generated on a ZSK-30 extruder. Reactive extrusion experiments were designed to graft Bionol® 1020 at low levels, ie about 3% and 5% HEMA. In addition, the effect of the peroxide addition was investigated at a constant HEMA addition level. Table 4 below shows reactive extrusion process conditions for the HEMA grafted Bionol® 1020 experiment.

Reactive extrusion parameters such as time, temperature,% torque and die pressure were monitored on the ZSK-30 extruder during the reactive extrusion of Bionol® 1020 and HEMA. Table 5 shows the process conditions during reactive extraction of each HEMA grafted Bionol® 1020 sample. The% torque and melting temperature of each HEMA grafted Bionol® 1020 is equal to or greater than unmodified Bionol® 1020.

With the HEMA level constant at 3.0%, the melt viscosity increased rapidly when the level of the Lupersol® 101 peroxide initiator was increased to 1.0%. Melt pressure nearly doubled from 107 psi to 180 psi compared to unmodified Bionol 1020. The melt strands were much denser and the polymer appeared to cause some crosslinking. The evidence of crosslinking was much clearer when Lupersol® 101 was increased to 1.2% at a HEMA level of 3.0%. The extruded strand showed a sharp melt fracture and the melt pressure increased even more to about 306 psi compared to unmodified Bionol 1020. At this point the experiment was discontinued and no samples could be collected at the 1.2% peroxide level. It is believed that the rapid characteristic change of HEMA grafted Bionol® 1020 at low monomer levels and higher peroxide levels is due to the complete crosslinking reaction. The reason why no crosslinking reaction was observed in PEG-MA grafted Bionol® 1040 on the Hake extruder was due to the following factors: (1) different extruders (including different axial shapes and residence times), (2) different polymers (1020 has a higher viscosity than 1040) It is thought to be due to one or more of (3) different monomers, and (4) most importantly lower peroxide levels. In reactive extrusion experiments with conventional bot polyethylene or polyethylene oxide, as the relative level of peroxide increased, the amount of crosslinking increased, resulting in an observed level of gel and melt fracture.

Significant differences in polymers, monomers, extruders, and process conditions made it difficult to compare PEG-MA grafted Bionol 1040 on a Hake extruder with HEMA grafted Bionol 1020 on a ZSK-30 extruder. . However, what is important in this series of experiments with Bionol® 1020 is that the reactive extrusion and polymer properties differ significantly from all conventional biodegradable reactive extrusion experiments using PLA, PHBV, or PBS on a Hake extruder. .

FIG. 6 shows a comparison of proton NMR spectra of grafted Bionol 1040 and Unmodified Bionol 1040 reactively extruded on a Hake extruder. A characteristic peak (CH ₃ ) of the grafted PEG-MA monomer was observed at 1.0 ppm. PEG-MA grafting level was determined to be 0.51% by weight of PBS.

Melt rheology was performed on unmodified Bionol 1020 and 1040, PEG-MA grafted Bionol 1040 modified on a Hake extruder, and HEMA grafted Bionol on a ZSK-30 extruder. Investigation was made on 1020. Measurements were carried out at 180 ° C. on a Göptert capillary rheometer according to the procedure described in the experimental section.

FIG. 7 shows melt rheological curves for PEG-MA grafted Bionol® 1040 and Unmodified Bionol® 1040 on a Hake extruder. The results show that PEG-MA grafted Bionol® 1040 has a lower melt viscosity than unmodified Bionol® 1040 in the entire shear rate range. Indeed, as the amount of PEG-MA added increased from 4.5% to 9%, the melt viscosity decreased further. This result was similar to that of PHBV and PLA grafting. The decrease in melt viscosity with increasing amount of monomer added, also observed in PEG-MA grafted Bionol 1040, was also observed in PEG-MA grafted polypropylene and polyethylene in conventional reactive extrusion operations. Similar to the effect.

8 shows melt rheological curves for HEMA grafted Bionol® 1020 and Unmodified Bionol® 1020 on a ZSK-30 extruder. The melt rheological properties of the grafted material are associated with the observed reactive extrusion properties. The 5% HEMA sample shows a slightly reduced melt viscosity compared to unmodified Bionol 1020 at low relative peroxide levels. All 3% HEMA samples show increased melt viscosity compared to unmodified Bionol 1020. The 3% HEMA sample also showed an increased melt viscosity due to crosslinking of the Bionol® 1020 polymer as the peroxide addition level increased. At 1.2% peroxide addition, 3% HEMA samples could not be collected and therefore no melt rheological data was collected.

Table 6 is DSC analysis data of PEG-MA grafted Bionol® 1040 and Unmodified Bionol® 1040 samples produced on a Hake extruder.

Table 7 shows DSC data for HEMA grafted Bionol® 1020 and Unmodified Bionol® 1020 samples generated in a ZSK-30 extruder.

PEG-MA grafted Bionol® 1040 on the Hake extruder showed an increased melt peak compared to unmodified Bionol® 1040. This result is surprising in that the grafted polymer typically exhibited a decrease in the melting peak upon grafting. FIG. 9 shows a comparison between DSC curves for unmodified Bionol 1040 and PEG-MA grafted Bionol 1040.

HEMA grafted Bionol® 1020 on a ZSK-30 extruder shows a reduction in both melt peak and melt enthalpy compared to unmodified Bionol® 1020. 10 shows a comparison between DSC curves for ungrafted Bionol® 1020 and HEMA grafted Bionol® 1020. Changes in the observed thermal properties were labels of the modified crystalline structure and indirect labels of HEMA grafting. The observed melt peak and reduction in melt enthalpy were more typical in grafted polymers such as HEMA grafted PHBV or conventional HEMA grafted polyester operations.

<Example 3>

Reactive Extrusion of PCL and HEMA

This example shows a reactive extrusion procedure for preparing grafted PCL. The same ZSK-30 two-screw extruder was used as in Example 2 above. Ton® P-787 PCL was fed to the feed passage of the ZSK-30 two-screw extruder at a rate of 20 pounds per hour. HEMA was fed to barrel # 5 at a rate of 0.36 lbs / hr (1.8 wt% of the PCL resin), and Lupersol® 101 peroxide at 0.03 lbs / hr (0.15 wt% of the PLC resin) It was supplied to barrel # 6. The axial speed was 300 rpm.

The following temperatures were recorded during this grafting process.

Melting temperature was 214 ° C. The melt pressure measured was 422 psi. The vacuum at the exhaust port (barrel # 11) to remove unreacted HEMA monomer was 24.49 in Hg.

The resulting grafted PCL was cooled in a water bath and pelleted into white pellets. The grafted PCL strands were strong and ductile. The surface of the strands and pellets was glossy.

Film casting of grafted PCL was carried out on a Hake 2-axis extruder described in Example 1, equipped with an 8-inch film die (Hake product). The film was cooled with a chill roll cooled with water at room temperature. The extruder had four heating zones set at temperatures of 120 ° C, 130 ° C, 130 ° C and 140 ° C, respectively. The axial speed was 40 rpm. The grafted PCL was fed full to the extruder. The melt temperature measured was 136 ° C to 137 ° C. Melt pressure ranged from 800 to 1,100 psi. A thin film having a thickness of about 1.5 mils was obtained. The film of grafted PCL was strong, glossy, and ductile. The film was clear and transparent. The grafted PCL film has a significant improvement in film transparency compared to the opaque film made from unmodified PCL.

The grafted PCL melt is more tacky than the ungrafted PCL, showing the potential as an adhesive for hot melt applications.

<Example 4>

Water Reactive Films of Biodegradable Polymers and Water-Soluble Polymers

A series of biodegradable and water soluble polymer blends were prepared using the ZSK-30 two-screw extruder described in Example 2.

In the first group of experiments, Bionol® 1020 PBS was used as the biodegradable polymer. PVOH was used as the water soluble polymer.

PVOH (Airfoil® 203, Air Products) control samples were extruded at a rate of 20 pounds per hour. The extruder temperature was set at 110 ° C. in zone 1, 150 ° C. in zones 2 and 3, 160 ° C. in zone 4, 170 ° C. in zone 5, and 180 ° C. in zones 6 and 7. Melting temperature was 199 ° C. Melt pressure was 197 psi. The axial speed was 300 rpm. The resulting film was transparent and water soluble.

Samples of the polymer blend were extruded using the same conditions as the control samples described above. Biool® 1020 PBS and Airvol® 203 PVOH were fed to the extruder independently in two gravity feeders to produce a blend of 80 wt% PVOH and 20 wt% PBS. Melt pressure was 174 psi. Melting temperature was 199 ° C. The extruded strands were smooth and well formed.

Example 5

Water Reactive Films of Biodegradable and Water-Soluble Polymers

The same procedure was followed as in Example 4 above, except that PBS and PVOH were fed at a rate that resulted in a blend of 70 wt% PVOH and 30 wt% PBS. Melt pressure was 192 psi. Melting temperature was 198 ° C. The extruded strands were smooth and well formed.

<Example 6>

Water Reactive Films of Biodegradable and Water-Soluble Polymers

The same procedure was followed as in Example 4 above, except that PBS and PVOH were fed at a rate that resulted in a blend of 60 wt% PVOH and 40 wt% PBS. Melt pressure was 202 psi. Melting temperature was 197 ° C. The extruded strands were smooth and well formed. The strand of extruded polymer was then converted to pellets.

<Example 7>

Films made from blends comprising PVOH and PBS

The pellets prepared in Examples 4-6 were made into films by melt extrusion casting process using a Hake two-axis extruder as described in Example 1. The temperatures in the four zones of the extruder were set at 170 ° C, 180 ° C, 180 ° C and 190 ° C. The axial speed was 100 rpm. The thickness of the resulting film was 1 mil.

The film produced from the pellets of Example 4 was water dispersible within 2 minutes in water at 22 ° C. The film produced using the pellets of Example 5 was water dispersible within 2 minutes in water at 22 ° C. The film produced using the pellets of Example 6 was water dispersible within 2 minutes in water at 22 ° C.

<Example 8>

Blends of Modified Biodegradable Polymers and Modified Water Soluble Polymers

The same ZSK-30 two-screw extruder as described in Example 2 above was used in the examples below. Two different feeders were used to feed two different polymers simultaneously into the feed passage of the extruder. Water-soluble polymers were supplied from PCL and National Starch and Chemical Co., Bridgewater, NJ, under the trade name NS 70-4442. NS 70-4442 was a water soluble sulfonated polyester polymer. PCL was fed to the extruder at a feed rate of 16 pounds per hour and NS 70-4442 was fed at a rate of 4 pounds per hour. At this feed rate the ratio PCL: NS 70-4442 was 80:20 by weight. HEMA was injected into barrel # 5 using an Eldex pump at a rate of about 0.4 pounds per hour. Lupersol® 101 was injected into barrel # 6 at an rate of 0.032 pounds per hour using an Eldex pump. The axial speed was 300 rpm. The temperature was as follows.

The melt temperature measured was 209 ° C. Melt pressure was 258 psi. The strand was cooled on a fan cooling conveyor belt and then pelletized. The strands and pellets were smooth on the surface.

Cast films were prepared from pellets on the Hake two-screw extruder described above. The film exhibited water sensitivity, ie reduced hardness, increased deformation and softness.

Example 9

Blends of Modified Biodegradable Polymers and Modified Water Soluble Polymers

The above example, except that the ratio of PCL: NS 70-4442 produced at a feed rate of PCL of 18 pounds per hour and NS 70-4442 of 12 pounds per hour was 60:40 by weight. The same procedure as described in 8 was followed. The temperature was as follows.

Melting temperature was 210 ° C. Melt pressure was 158 psi. Films made from the blended compositions were water sensitive. Increasing the amount of NS 70-4442 in the blend could improve the water sensitivity of the film, making the film water dispersible or water disintegratable.

<Example 10>

Polylactide (PLA) was Catalog # 43232-6 from Aldrich Chemical Company. Poly (butylene) succinate (PBS) was supplied under the trade name Bionol 1020 from Showa High Polymer Company. Polyvinyl alcohol (PVOH) was supplied by Nippon Gohsei under the trade name Ecomaty® AX10000.

PLA grafted with 2-hydroxyethyl methacrylate was used. The grafted PLA was produced by reactive extrusion on a Warner and Flyderer ZSK-30 two-axis extruder. The procedure for preparing the grafted PLA was described in the above examples.

2-hydroxyethyl methacrylate (HEMA) and polyethylene glycol ethyl ether methacrylate (PEG-MA) of molecular weight 246 g / mol, all provided by Aldrich Chemical Company, were used as reactive polar vinyl monomers. The peroxide initiator used was lupersol® 101 provided by Atochem.

Blends were created using a Rheomix® 600 two-roller mixer (manufactured by Hake). The mixer had three heating zones for the front plate, mixing chamber and back plate, respectively. The temperature, axis speed, and mixing time of the zones were computer controlled.

Typical polymer blending experiments in a Hake mixer were performed as follows. The mixer was preheated to 180 ° C. A certain amount of PLA or grafted PLA and PVOH was added to the mixer and the materials were mixed for 5 minutes at an axial speed of 150 rpm. After 5 minutes, the melt was taken out of the mixer and cooled in air.

The blend was also produced using a TW-100 two-axis extruder (manufactured by Hake) with three barrels and a processing length of 300 mm. The instrument had a conventionally manufactured reverse cone-shaped 2-axis. The feed zone was not heated but cooled with water. The extruder had three heating zones named zone 1, zone 2 and zone 3 in the die direction in the feed zone. The die was named band 4. The die had two openings of diameter 3 mm spaced by 10 mm.

Typical polymer blending experiments on a Hake extruder were performed as follows. The heating zones were preheated to 170 ° C, 180 ° C and 180 ° C. The extruder was set at 150 rpm. Pellets of PLA or grafted PLA were mixed with pellets of PVOH in a certain proportion. The mixture of resin pellets was cooled twice in succession and pelletized twice.

In contrast to the two-step process, new methods have been developed for the development of flushable biodegradable polymers using only one extrusion pass. This method is called reactive blending. In the reactive blending method, biodegradable polymers and water soluble polymers are blended with reactive grafting with polar monomers. At the end of the extruder, the melt is extruded, cooled and pelletized.

Reactive blends are likely to contain one or more of some unreacted and reacted products. Some of the unreacted biodegradable polymer and water soluble polymer may remain in the final reactive blend. The grafted biodegradable polymers and water soluble polymers are possible reaction products in reactive blends. In addition, the reactive blend may contain some biodegradable polymers and water soluble polymers connected by reaction, which are novel material compositions.

Compared to the two-step process, the one-step reactive blending process provides several advantages and benefits. The one-stage reactive blending process is 1) a lower cost process since it requires only one extrusion, cooling and pelleting cycle, 2) one less extrusion pass reduces polymer degradation, and 3) the resulting blend. The variation in the quality and the polymer blend composition is smaller.

Reactive blending was performed on the aforementioned Hake TW-100 two-screw extruder. Typical reactive blending experiments on a Hake extruder were performed as follows. The heating zone was preheated to 160 ° C, 180 ° C, 180 ° C, 190 ° C. The extruder was set at 150 rpm. Pellets of PBS were mixed with pellets of PEO in a certain proportion. The mixture of resin pellets was fed to a Hake extruder at a throughput of 5 pounds per hour using a volumetric feeder. PEG-MA was added to the feed zone at 5 pounds per hour and lupersol® 101 was added to the feed zone at 0.025 pounds per hour. After the addition of PEG-MA and Lupersol® 101, the torque decreased and then stabilized. The process was allowed to equilibrate and the extruded strands were cooled in air and pelletized.

Reactive blends of PBS and PEO with PEG-MA were converted to thin films using the same Hake extruder, except that 4-inch or 8-inch slit dies were used instead of 2-strand dies. The film was collected using a cooled outer-up roll maintained at 15-20 ° C. Die gap, axial speed and wind-up speed were adjusted to optimize film processing and film thickness.

Typical film-phone work was carried out on a Hake extruder as follows. The selected reactive blend pellets were fed to the feed zone full. The temperature profiles of the four heating zones were 170 ° C, 180 ° C, 180 ° C and 190 ° C. The melting temperature at the die was 195 ° C. The axial speed was 30 rpm. The wind-up rate was 70% of maximum. Process conditions were adjusted to produce a film having a thickness of about 4 mils. The process was stabilized and the film collected.

Dry tensile tests were performed on the syntech 1 / D tensile tester under the following conditions: gauge length 30 mm, crosshead speed 4 mm, narrow width 3.18 mm of dogbone samples. A wet tensile test was also conducted under the same conditions on a Syntec 1 / D Tensile Tester, except that the film was immersed in water during the test. A water tank was used for the wet tensile test. Maximum stress, percent strain-to-destruction, energy-to-destruction (bottom area of the stress versus strain curve), and modulus are calculated for each film test and the percent loss of tensile properties of the wet test for the dry test is measured. It was.

DSC was performed on a TA Instruments DSC 2910. 10-15 mg of film samples were used for each test. For each test, the following method was followed. (1) equilibrate at -20 ° C, (2) isothermal for 1 minute, (3) ramp to 200 ° C at 20 ° C / min, (4) ramp to 30 ° C at 30 ° C / min.

Melt rheological tests were performed at 195 ° C. (melt temperature observed in most film-conversion operations) on a Götpert Leograph 2003 with a 30/1 mm L / D die. The apparent melt viscosity of each material was measured at an apparent shear rate of 50, 100, 200, 500, 1000, 2000 sec-1. Rheological curves of apparent viscosity versus apparent shear rate were plotted for each material.

The wet tensile properties of the physical and reactive blends of PBS / PEO were tested and compared to the dry pull properties. Tables 8 and 9 show the dry and wet tensile properties of the physical blends and reactive blend films of 20/80, 30/70 and 40/60, respectively. The percent loss of tensile properties in the wet test for the dry test was recorded for strain, strength, toughness and stiffness. 50/50 and 60/40 blends were not included because they were water sensitive but did not significantly lose their tensile properties in water.

In the 20/80 and 30/70 compositions, the reactive blends had a greater% loss of tensile properties in the wet test for the dry test compared to the physical blend, which was highly desirable for washable applications. The relative loss of tensile properties in the wet test to the dry test was clearly increased in the reactive blend film.

Surprisingly, the physical and reactive blends of 40/60 PBS / PEO showed increased percent strain versus fracture. In addition, the physical blend of 30/70 PBS / PEO showed an increase in percent strain versus fracture. Indeed, when these blends were exposed to water, the films appeared to have somewhat elastomeric properties. This observation was surprising in that similar blends of other polymer systems always showed a decrease in tensile properties after most water soluble components were dissolved in water. It is evident that the plasticizing effect due to the hydration of PEO, the unique "layered" morphology of the physical and reactive blends of PBS / PEO, and the interaction between PBS and PEO contributed to the unique wet tensile properties of these blends. The elastomeric properties of the reactive blends also show the potential for development as a gasket to improve flush fit while being able to flush.

11 and 12 show SEM (scanning electron microscope) images of the topological morphology of the fracture surface of the physical and reactive blend films of 60/40 PBS / PEO. In FIG. 11, two-phase microstructure was observed in the physical blend. The adhesion between the PBS continuous phase and the PEO dispersed phase is very poor, as shown by the presence of holes left by PEO particles pulled out of PBS at the interface of the two phases. In FIG. 12, the compatibility of PBS and PEO was dramatically improved in the case of reactive blends. In fact, the second image is not visible in the SEM photograph of the reactive blend film. This observation suggests high compatibility in reactive blending, or possibly even miscibility of PBS and PEO.

The observed improvement in blend compatibility by reactive blending is further supported by the compositional mapping of the same fracture surface of the physical and reactive blend films of 60/40 PBS / PEO by BEI (backscatter electron imaging). BEI images are shown in FIGS. 13 and 14. The PBS phase, which has a higher average atomic number, shows a brighter image on the photograph. PEO phases have lower average atomic numbers and appear darker phases. In FIG. 13, the dispersed PEO phase was easily observed throughout the physical blend film, with sizes ranging from 1 to 3 microns. However, in FIG. 14, no PEO phase was observed in an area greater than 95% of the total area of the image of the reactive blend film (although PEO is 40% of the blend). Only some dark particles that could be due to PEO were observed in the image.

Analysis of the thermal properties of the physical and reactive blends of PBS / PEO by differential scanning calorimetry (DSC) was performed using the following procedure. DSC was performed on a TA Instruments DSC 2910. 10-15 mg of film samples were used for each test. For each test, the following method was followed. (1) equilibrate at -20 ° C, (2) isothermal for 1 minute, (3) ramp to 200 ° C at 20 ° C / min, and (4) ramp to 30 ° C at 30 ° C / min. Table 10 shows the data of DSC analysis.

In the case of reactive blends, it was observed that both the melt peak (T _m ) and the melt enthalpy (ΔH) decreased compared to the physical blends of the same mass ratio. It was also observed that the melt peak on the PEO of the PBS / PEO reactive blend decreased with increasing PEO content in the blend. Changes in the observed thermal properties were labels of the modified crystalline structure and indirect labels of grafting.

15 shows that the T _m on the PEO of the PBS / PEO reactive blend decreased as% PEO in the blend increased. 16 shows that the% PEO blend increased reactivity of T change (ΔT _m) in _m on the PEO in the blend resulting from the hayeoteum increased compared to the physical blend.

17 shows a comparison between the physical blend of 30/70 PBS / PEO and the DSC curve of the reactive blend. Both curves show two characteristic melting peaks. The first is the melting peak of PEO and the second is the melting peak of PBS. The curve shows a decrease in T _m and ΔH for the PEO and PBS components.

Melt rheology for the physical and reactive blends of PBS / PEO was investigated using the following procedure at 195 ° C. on a Götpert capillary rheometer. Melt rheological tests were performed at 195 ° C. (which is the melting temperature observed in most film-conversion operations) on a Göptert Leograph 2003 with a 30/1 mm L / D die. The apparent melt viscosity of each material was measured at an apparent shear rate of 50, 100, 200, 500, 1000, 2000 sec-1. Rheological curves of apparent viscosity versus apparent shear rate were plotted for each material.

18 shows the melt rheological curves of the physical and reactive blends of 20/80 and 60/40 PBS / PEO, as well as the melt rheological curves of PBS alone. The results indicate that the physical blend has a higher melt viscosity than the reactive blend in the entire shear rate range. Also, the greater the amount of PBS, the lower the melt viscosity in both the physical and reactive blends. The observed decrease in melt viscosity of the reactive blend was thought to be due to the lubricating effects of grafted PEG-MA and unreacted PEG-MA, and improved compatibility due to reduced molecular weight and reactive blending. The decrease in melt viscosity was an indirect indicator of chemical modification of PBS and / or PEO due to reactive blending with PEG-MA. The decrease in melt viscosity with increasing PBS composition was thought to be due to the lower viscosity of PBS than PEO. Due to the low melt viscosity of the reactive blend, fiber-spinning is possible for further application of the PBS / PEO reactive blend.

<Example 11>

As shown in Example 1, the grafting of PHBV with HEMA by a continuous reactive extrusion process was not practical because the grafted PHBV did not solidify or crystallize at a sufficient rate. The following example shows how to modify the grafted PHBV so that the grafted PHBV can be produced by a continuous reactive extrusion process.

The same Hake counter-rotating two-screw extruder as in Example 1 was used. Four temperature zones were set at 170 ° C, 200 ° C, 190 ° C and 190 ° C, respectively. The axial speed was 150 rpm. A mixture of PLA and PHBV with a weight ratio of 1: 1 was fed to the extruder at a throughput of 5.0 pounds per hour using a volumetric feeder. PHBV was the same as used in Example 1. PLA was purchased from Aldrich Chemical Company, Milwaukee, WI (Aldrich Catalog No. 42,232-6). PLA was a biodegradable polymer with a number average molecular weight of about 6,000 g / mol. The weight average molecular weight was about 144,000 g / mol. HEMA monomer and lupersol® 101 were injected into the extruder at throughputs of 0.5 pounds / hour and 0.025 pounds / hour, respectively. HEMA and lupersol® 101 were the same as used in Example 1. The stranded strands quickly solidified and readily pelletized directly.

<Example 12>

The same procedure and extrusion conditions as in Example 11 were used except that the feed rate of the polymer mixture was increased to 8.7 lb / hr. Even at this high extrusion rate, the extruded strands quickly solidified and readily pelletized directly.

Example 13

The same procedure and extrusion conditions as in Example 12 were used except that HEMA was replaced with butyl acrylate. Butyl acrylate was fed at a rate of 0.86 pounds per hour and lupersol® 101 was fed at a rate of 0.044 pounds per hour. The extruded strands quickly solidified and were easily pelletized directly.

<Example 14>

The same procedure as in Example 11 was followed except that the temperature zones were set at 170 ° C, 180 ° C, 180 ° C and 190 ° C, respectively. In addition, PLA was replaced with PEO. A mixture of PEO and PHBV with a weight ratio of 50:50 was fed to the extruder at a throughput of 5.0 pounds per hour using a volumetric feeder. PEO was the same as used in Example 10. HEMA monomer and lupersol® 101 were injected into the extruder at throughputs of 0.5 pounds / hour and 0.025 pounds / hour, respectively. The extruded strands quickly solidified and were easily pelletized directly.

<Example 15>

The same procedure was followed as in Example 14 except that HEMA was replaced with PEG-MA. The extruded strands quickly solidified and were easily pelletized directly.

It is to be understood that these examples are exemplary embodiments and that the present invention is not limited by any example or detailed description. Rather, the claims appended hereto are to be understood broadly within the scope and spirit of the invention.

Claims (33)

Water-responsive homogeneous polymers comprising biodegradable polymers grafted with polar monomers, oligomers or polymers or combinations thereof, and water soluble polymers grafted with polar monomers, oligomers or polymers or combinations thereof Blend composition. The composition of claim 1 wherein the biodegradable polymer is selected from hydrolyzable, poly (hydroxy alkanoate), poly (alkylene succinate), polycaprolactone or mixtures thereof. The method of claim 1 wherein the biodegradable polymer is poly (β-hydroxybutyrate-co-β-hydroxyvalerate), poly (ethylene succinate), poly (butylene succinate), polycaprolactone or their Composition selected from mixtures. The composition of claim 1, wherein the polar vinyl monomer is an ethylenically unsaturated monomer containing at least one polar functional group or the oligomer or polymer is an oligomer or polymer polymerized from an ethylenically unsaturated monomer containing at least one polar functional group. . The composition of claim 4, wherein the at least one polar functional group is a hydroxyl group, a carboxyl group, a cyano group, an amino group, a sulfonate group or a combination thereof. 4. The composition of claim 3, wherein said at least one polar functional group is a hydroxyl group. The composition of claim 1 wherein said polar monomer is a polar vinyl monomer. The method of claim 1, wherein the polar monomer is poly (ethylene glycol) acrylate, poly (ethylene glycol) alkyl ether acrylate, poly (ethylene glycol) methacrylate, poly (ethylene glycol) alkyl ether methacrylate, acrylic acid, Maleic anhydride, itaconic acid, sodium acrylate, 3-hydroxypropyl methacrylate, 2-hydroxyethyl methacrylate, 3-hydroxypropyl acrylate, 2-hydroxyethyl acrylate, acrylamide, glycy Dill methacrylate, 2-cyanoethyl acrylate, glycidyl acrylate, 4-nitrophenyl acrylate, pentabromophenyl acrylate, poly (propylene glycol) methacrylate, poly (propylene glycol) acrylate, 2-propene-1-sulfonic acid and its sodium salt, 2-sulfoethyl acrylate, 2-sulfoethyl methacrylate, 3-sulfopropyl acrylate , 3-sulfopropyl methacrylate or a mixture thereof. The composition of claim 1, wherein the polar monomer, oligomer or polymer is selected from 2-hydroxyethyl methacrylate, polyethylene glycol methacrylate or analogs thereof. The composition of claim 1 wherein said polar monomer, oligomer or polymer is 2-hydroxyethyl methacrylate or a derivative thereof. The method of claim 1 wherein the polar monomer, oligomer or polymer is selected from 2-hydroxyethyl methacrylate, polyethylene glycol methacrylate or analogs thereof and the biodegradable polymer is poly (β-hydroxybutyrate-co -β-hydroxy valerate), poly (ethylene succinate), poly (butylene succinate), polycaprolactone or mixtures thereof. The composition of claim 1, wherein the biodegradable polymer contains 1 to 20% by weight of grafted polar monomers, oligomers or polymers or combinations thereof. The composition of claim 1 wherein the water soluble polymer is selected from polyethylene oxide, polyvinyl alcohol, hydroxypropyl cellulose or polyacrylic acid. The method according to claim 1, wherein the biodegradable polymer is selected from poly (hydroxy alkanoate), poly (alkylene succinate), polycaprolactone or mixtures thereof, wherein the polar monomer, oligomer, or polymer is 2- Selected from hydroxyethyl methacrylate, polyethylene glycol methacrylate, or analogues thereof, wherein the water soluble polymer is selected from polyethylene oxide, polyvinyl alcohol, sulfonated polyester, hydroxypropyl cellulose, polyacrylamide or polyacrylic acid Phosphorus composition. A homogeneous water-dispersible polymer blend comprising from 1% to 35% by weight grafted biodegradable polymer and from 65% to 99% by weight water soluble polymer or grafted water soluble polymer. A homogeneous water-disintegratable polymer blend comprising 35% to 45% grafted biodegradable polymer and 55% to 65% water soluble polymer or grafted water soluble polymer. A homogeneous water-weakenable polymer blend comprising 45% to 55% grafted biodegradable polymer and 45% to 55% water soluble polymer or grafted water soluble polymer. A film comprising the composition of claim 1. A fiber comprising the composition of claim 1. An article comprising the composition of claim 1. Blending a biodegradable polymer and a water soluble polymer grafted with a polar monomer, oligomer or polymer or a combination thereof under high shear force at a temperature above the melting temperature of the water soluble polymer and below the decomposition temperature of the water soluble polymer, Admixing the blend to form a homogeneous polymer blend composition, wherein said method comprises: producing a homogeneous polymer blend composition that is optionally water-sensitive. The method of claim 21, wherein the biodegradable polymer is selected from hydrolytically degradable poly (hydroxy alkanoate), poly (alkylene succinate), polycaprolactone or mixtures thereof. The method of claim 21 wherein the biodegradable polymer is poly (β-hydroxybutyrate-co-β-hydroxyvalerate), poly (ethylene succinate), poly (butylene succinate), polycaprolactone or their And selected from the mixture. The method of claim 21, wherein the polar vinyl monomer is an ethylenically unsaturated monomer containing at least one polar functional group or the oligomer or polymer is an oligomer or polymer polymerized from an ethylenically unsaturated monomer containing at least one polar functional group. . The method of claim 21 wherein said at least one polar functional group is a hydroxyl group, a carboxyl group, a sulfonate group or a combination thereof. The method of claim 21, wherein the polar monomer is a polar vinyl monomer. The method of claim 21, wherein the polar monomers are poly (ethylene glycol) acrylate, poly (ethylene glycol) alkyl ether acrylate, poly (ethylene glycol) methacrylate, poly (ethylene glycol) alkyl ether methacrylate, acrylic acid, Maleic anhydride, itaconic acid, sodium acrylate, 3-hydroxypropyl methacrylate, 2-hydroxyethyl methacrylate, 3-hydroxypropyl acrylate, 2-hydroxyethyl acrylate, acrylamide, glycy Dill methacrylate, 2-cyanoethyl acrylate, glycidyl acrylate, 4-nitrophenyl acrylate, pentabromophenyl acrylate, poly (propylene glycol) methacrylate, poly (propylene glycol) acrylate, 2-propene-1-sulfonic acid and its sodium salt, 2-sulfoethyl acrylate, 2-sulfoethyl methacrylate, 3-sulfopropyl acrylate The method, 3-sulfopropyl methacrylate, or is selected from a mixture thereof. The method of claim 21, wherein the polar monomer is selected from 2-hydroxyethyl methacrylate, polyethylene glycol methacrylate, or analogs thereof. The method of claim 21 wherein the water soluble polymer is selected from polyethylene oxide, polyvinyl alcohol, hydroxypropyl cellulose or polyacrylic acid. The method of claim 21 wherein the biodegradable polymer is poly (β-hydroxybutyrate-co-β-hydroxyvalerate), poly (ethylene succinate), poly (butylene succinate), polycaprolactone or their The polar monomer is selected from 2-hydroxyethyl methacrylate, polyethylene glycol methacrylate or an analog thereof, and the water soluble polymer is polyethylene oxide, polyvinyl alcohol, hydroxypropyl cellulose, polyacrylamide , Sulfonated polyester or polyacrylic acid. Biodegradable polymers, water soluble polymers, polar vinyl monomers and free radical initiators are grafted with the biodegradable polymers and the water soluble polymers into the polar vinyl monomers and the heat, high enough to form a homogeneous blend of the biodegradable polymers and the water soluble polymers. A method of making a water reactive biodegradable polymer blend composition comprising a single step of blending under shear and high strength dispersible mixing. A water sensitive polymer blend of a modified water soluble polymer with a biodegradable polymer selected from modified, hydrolytically degradable poly (hydroxy alkanoate), poly (alkylene succinate), polycaprolactone or mixtures thereof. A water sensitive polymer blend of a modified poly (ethylene) oxide with a modified, hydrolytically degradable poly (hydroxy alkanoate), poly (alkylene succinate), polycaprolactone or mixtures thereof.