MXPA00006566A - Grafted poly(ethylene oxide) compositions - Google Patents

Abstract

Modified poly(ethylene oxide) compositions are disclosed. The poly(ethylene oxide) compositions have improved melt processability and properties and can be used to thermally process articles which have improved properties over articles similarly processed from unmodified poly(ethylene oxide) compositions.

Description

POLYMER COMPOSITIONS (ETHYLENE OXIDE) GRAFTED FIELD OF THE INVENTION The present invention is directed to poly (ethylene oxide) compositions. More particularly, the present invention is directed to improved poly (ethylene oxide) compositions, to methods for improving the melt processing of poly (ethylene oxide) and to improving poly (ethylene oxide) films and fibers.

BACKGROUND OF THE INVENTION Disposable personal care products such as panty liners, diapers, caps, etc., are of great convenience. Such products provide the benefit of a one-time sanitary use and are convenient because they are quick and easy to use. However, the disposal of such products is a concern due to limited land space. The incineration of such products is undesirable due to concerns about air quality and increase due to the difficulty associated with the separation of such products from other non-incinerable discarded items. Consequently, there is a need for disposable products which can be quickly and conveniently discarded without being thrown into the landfill or resorting to incineration.

It has been proposed to dispose of such products in municipal and tested drainage systems. Ideally, such products will be disposable with water discharge and degradable in conventional drainage systems. The products suitable for the disposal in the drainage systems and that can be discarded with discharge of water in the conventional toilets s called "disposable with discharge of water". Disposal through waste disposal with water provides the additional benefit of providing a simple, convenient sanitary disposal means. Personal care products must have sufficient resistance under environmental conditions in which they will be used and must be able to withstand the conditions of humidity and elevated temperature encountered during use and storage but which still lose their integrity In contact with water in the toilet Therefore, a water-disintegrable material that has mechanical integrity when dry is desirable.

Due to the unique interaction with water and body fluids, poly (ethylene oxide) (hereinafter referred to as PEO) is currently considered a component material for water-disintegrable films, fiber and disposable products with discharge of water. Polyethylene oxide d, - (CHCH2) n- is a commercially available water-soluble polymer which can be produced from the ring-opening polymerization of ethylene oxide, 0 / \ CH2-CH2.

Due to its properties of being soluble in water, polyethylene oxide is desirable for disposable applications with water discharge. However, there is a dilemma in the melt processing of polyethylene oxide. The low molecular weight polyethylene oxide resins have desirable melt viscosities and melt pressure properties for melt processing but have limited solid state properties when processed with melt and structural articles such as films.

An example of a low molecular weight polyethylene oxide resin is polyethylene oxide POLYOX® WSR N-80 which is commercially available from Union Carbide. POLYOX® WSR N-80 polyethylene oxide has a molecular weight of approximately 200,000 g / mol as determined by rheological measurements. As used herein, low molecular weight polyethylene oxide compositions are defined as polyethylene oxide compositions with an approximate molecular weight of less than and including about 200,000 g / mol In the personal care products industry, disposable thin gauge films with water discharge and cast-spun fibers are desirable for commercial viability and ease of disposal. The low melt strength and the low melt elasticity of low molecular weight polyethylene oxide limit the ability of the low molecular weight polyethylene oxide to be drawn into films having a thickness of less than about 1.2 mils. Even when low molecular weight polyethylene oxide can be thermally processed in films, thin gauge films less than about 1 mil inch thick can not be obtained due to the lack of melt strength and melt elasticity of the low molecular weight polyethylene oxide. Efforts have been made to improve the processing of the polyethylene oxide by mixing the polyethylene oxide with a second polymer, or copolymer of ethylene and acrylic acid, in order to increase the strength in the melt. The mixture of ethylene acrylic acid copolymer / polyethylene oxide is capable of being processed into films about 1.2 mils thick.

However, the mixture and the resulting film are not soluble in water, especially at high levels of ethylene acrylic acid copolymer, for example, of about 30% by weight. More importantly, thin films made of low molecular weight polyethylene oxide are very weak and brittle to be useful for personal care applications Low molecular weight polyethylene oxide films have a low tensile strength, a ductility Low are very brittle for commercial use. In addition, the films produced from the low molecular weight polyethylene oxides are brittle during storage under environmental conditions. Such films are broken and are not suitable for commercial applications.

High molecular weight polyethylene oxide resins are expected to produce films with improved mechanical properties compared to films produced from low molecular weight polyethylene oxide resins. An example of a higher molecular weight polyethylene oxide is polyethylene oxide POLYOX® WSR 12K which is commercially available from Union Carbide. Polyethylene oxide POLYOX® WSR 12K has a reported approximate molecular weight of 1,000,000 g / mol as measured by rheological measurements. As used herein, high molecular weight polyethylene oxides are defined as polyethylene oxides with an approximate molecular weight of more than including about 300,000 g / mol.

The higher molecular weight polyethylene oxides have poor processability due to their high melt viscosities and poor melt pulls. The melt pressure and the melt temperature are significantly increased during the melt extrusion of the higher molecular weight polyethylene oxide. During the extrusion of the higher molecular weight polyethylene oxides, s observe a severe melt fracture. Only the thick mu sheets can be made of polyethylene oxides of higher molecular weight. The higher molecular weight polyethylene oxides can not be thermally processed into films d less than about 3-4 mils thick. The higher molecular weight polyethylene oxides suffer from severe melt degradation during melt extrusion and processing. This results in the breakdown of the polyethylene oxide molecules and bubble formation in the extrudate. The inherent deficiencies of higher molecular weight polyethylene oxides make it impossible to use higher molecular weight polyethylene oxides in film applications. Even the addition of high levels of plasticizer to the higher molecular weight polyethylene oxides does not improve the melt processing sufficiently to allow the production of thin films without the melt fracture and without film breakage occurring. Furthermore, the use of the plasticizer in the films causes latent problems due to the migration of the plasticizer to the surface of the film.

There is also a dilemma in the use of polyethylene oxide d in fiber manufacturing processes. Low molecular weight polyethylene oxide resins, for example of 200,000 g / mol have a desirable melt viscosity melt pressure properties for extrusion processing but can not be processed into fibers due to their low melt elasticities and their strengths of low melt. Polyethylene oxide resins of higher molecular weight, for example, greater than 1,000,000 g / mol have melt viscosities that are very high for fiber spinning processes. These properties make conventional polyethylene oxides difficult to process into fibers using conventional fiber manufacturing processes.

The molten and extruded polyethylene oxide from spinning plates and from fiber spinning lines resist and pull and break easily. Polyethylene oxide resins do not form thin diameter fibers using conventional fiber manufacturing processes. Conventional polyethylene oxide resins can only be processed by melting on yarns with diameters in the range of several millimeters. Therefore, polyethylene oxide compositions with melt viscosities suitable for fiber processing and with higher melt elasticities melt strengths are desired.

In the personal care industry, disposed fused and discharged fibers with water discharge are desired for their commercial viability and ease of disposal. The polyethylene oxide fibers have been produced by means of a solution setting process. However, it has been possible to melt-process polyethylene oxide fibers using conventional fibermaking techniques such as melt spinning. The melt processing techniques are more desirable than the melt solution because the melt processing techniques are more efficient and economical. The melt processing of fibers is necessary for commercial viability. The polyethylene oxide compositions of the prior art can not be extruded into the melt with a suitable melt strength and elasticity to allow fiber attenuation. Currently, fibers can not be produced from conventional polyethylene oxide compositions by means of co-melted spinning.

Therefore, currently available polyethylene oxide resins are not practical for melt processing in thin film applications, fiber personal care applications. What is required in the art, therefore, are polyethylene oxide compositions that overcome the difficulties in melt processing.

SYNTHESIS OF THE INVENTION The present invention is directed to methods for improving the processing of polyethylene oxide. More particularly, the present invention relates to methods for modifying polyethylene oxide to improve melt processing by grafting polar vinyl monomers, such as poly (ethylene glycol), methacrylate or 2-hydroxyethyl methacrylate, onto the polyethylene oxide. And grafting is achieved by mixing the polyethylene oxide with the monomer or monomers and the initiator and applying heat. In a preferred embodiment, the modification method is a reactive extrusion process. The modified polyethylene oxides according to this invention have improved melt processing and can be thermally processed into films, fiber and other articles which have improved properties on films, fibers and similarly processed articles of unmodified polyethylene oxide compositions.

To overcome the disadvantages of the prior art, this invention teaches a method for grafting polar functional groups into the polyethylene oxide in the melt. Modification of polyethylene oxide reduces melt viscosity, melt pressure and melt temperature Additionally, modification of the polyethylene oxide of higher molecular weight according to the invention eliminates severe fluid fracture observed when extruding the weight polyethylene oxide higher molecular weight. The invention provides methods for producing thermally processable and improved polyethylene oxide resins by modifying the polyethylene oxide. Modified polyethylene oxide resins can be pelletized for further thermal processing in useful forms such as thin films and fibers which in turn are useful as components in personal care products.

As used herein, the term "graft copolymer" means a copolymer produced by combining two or more chains of constitutional or configurationally different characteristics, one of which serves as a column backbone, and at least one of which is united in some points along the column and constitutes a side chain. As used herein, the term "graft" means the formation of a polymer mediating the joining of side chains or species at some point or point along the column of a parent polymer (see Sperling, LH, Introduction to the Science of the Physical Polymer 1986, pages 44-47 which is hereby incorporated by reference in its entirety).

Modification of polyethylene oxide resins with starting molecular weights of between about d 300,000 g / mol to about 8,000,000 g / mol allows the modified polyethylene oxide resins to be pulled and films with thicknesses of less than 0.5 thousandths of an inch The modification of polyethylene oxide resins with starting molecular weights of between about 400,000 g / mol around 8,000,000 is preferred for the manufacture of films. The drawn films of the modified polyethylene oxide compositions have a better softness and better clarity than the unmodified low molecular weight polyethylene oxide pulled films. The thermal processing of the modified higher molecular weight polyethylene oxide films in accordance with this invention also results in films with improved mechanical properties over similarly processed films of unmodified low molecular weight polyethylene oxide films.

Modification of polyethylene oxide resins with starting molecular weights of between about 50,000 g / mol to about 400,000 g / mol allows modified polyethylene oxide resins to be extruded into fibers using melt spinning processes conventional Modification of polyethylene oxide resins with starting molecular weights of between about 50,000 g / mol around 200,000 g / mol is preferred for the manufacture of fibers. The modification of the polyethylene oxide according to this invention improves the melting properties of the polyethylene oxide by allowing the modified polyethylene oxide to be melted and attenuated into fibers. Therefore, the modified polyethylene oxide can be processed into water soluble fibers using both spinning and spin bonding processes which are useful for liners, outer covers, cloth type, etc., in the products for disposable person care with water discharge.

These and other features and advantages of the present invention will become apparent upon review of the following detailed description of the embodiments described.

BRIEF DESCRIPTION OF THE FIGURES Figure 1 compares the melt rheology curve of an unmodified polyethylene oxide resin d 600,000 g / mol of approximate molecular weight, Example 1, and the melt rheology curve of the modified polyethylene oxide compositions of the resin of polyethylene oxide of molecular weight of 600,000 g / mol, Examples 2-5.

Figure 2 compares the melt rheology curve of an unmodified polyethylene oxide resin of approximate molecular weight of 1,000,000 g / mol. Example 6, and the melt rheology curves of modified polyethylene oxide compositions of the polyethylene oxide resin of molecular weight of 1,000,000 g / mol, Example 7-10.

Figure 3 shows the results of the infrared Fourier transform spectrum analysis of unmodified polyethylene oxide films of 600,000 g / mol of approximate molecular weight, Example 1; a polyethylene oxide of approximate initial molecular weight of 600,000 g / mol modified with 4.9% by weight of HEMA and 0.28% by weight of initiator. Example 3; and a polyethylene oxide of an initial approximate molecular weight of 600,000 g / mol modified with 4.9% by weight of PEG-MA and 0.32% by weight of initiator, Example 5.

Figure 4 compares the melt rheology curve of a polyethylene oxide resin of an approximate molecular weight of 600,000 g / mol, Example 1, and the melt rheology curves of the modified polyethylene oxide compositions of the polyethylene oxide having an initial approximate molecular weight of 600,000 g / mol with low initiator and monomer levels, Examples 11-13.

Figure 5 compares the melt rheology curve of an unmodified polyethylene oxide of a molecular weight of about 300,000 g / mol, Example 14, and the melt rheology curves of the modified polyethylene oxide compositions of the polyethylene having an approximate initial molecular weight of 300,000 g / mol Examples 15 and 16.

Figure 6 compares the melt rheology curve of an unmodified polyethylene oxide of a molecular weight of about 400,000 g / mol, Example 17, and the melt rheology curve of modified polyethylene oxide polyethylene oxide compositions which they have an initial approximate molecular weight of 400,000 g / mol, Examples 18 and 19.

Figure 7 is a graph comparing the melt viscosities of a polyethylene oxide of molecular weight of 200,000 g / mol unmodified, Comparative Example A against the melt viscosities of the same polyethylene oxide resin after modification , Example 32.

Figure 8 is a 13C Nuclear Magnetic Resonance Spectrum of the modified polyethylene oxide of Example 32.

Figure 9 is a Magnetic Resonance Spectrum Nuclear 1H of the modified polyethylene oxide of Example 32.

DETAILED DESCRIPTION The improved films and fibers can be melt processed using conventional methods of commercially available polyethylene oxide resins when modified in accordance with this invention. The polyethylene oxide resins useful for modification for the purposes of filmmaking include, but are not limited to, polyethylene oxide resins having approximate initial reported molecular weights ranging from about 300,000 g / mol to about 8,000,000. g / mol as determined by means of rheological measurements. Such polyethylene oxide resins are commercially available from, for example Union Carbide Corporation and are sold under the trade designations POLYOX® WSR N-750 and polymer 309 POLYOX® UCARFLOC® respectively. The modification of the polyethylene oxide resins with the starting molecular weights of about 300,000 g / mol about 8,000,000 g / mol as desired and the modification of the polyethylene oxide resins with the starting molecular weights from about from 400.00 g / mol to around 8,000,000 are more desired. Commercially available resin within the desired ranges includes but is not limited to POLYOX® WSR N-205 and POLYOX® WSR N-12K.

The fibers can be made using conventional processing methods of commercially available polyethylene oxide resins when modified in accordance with this invention. The polyethylene oxide resins useful for modification for fiber manufacturing purposes include, but are not limited to, polyethylene oxide resins having approximate initial reported molecular weights ranging from about 50,000 g / mol to about 400,000. g / mol The higher molecular weights are desired because of their increased mechanical and physical properties the lower molecular weights are desired by the ease of processing. The desirable polyethylene oxide resins for the manufacture of fibers have molecular weights ranging from 50,000 to 300,000 g / mol before modification and the most desired polyethylene oxide resins for fiber manufacture have molecular weights ranging from 50,000 200,000 g / mol before the modification. The modified polyethylene oxide compositions of the polyethylene oxide resins within the aforementioned resins provide desirable balance between the physical and mechanical properties of the processing properties. Two polyethylene oxide resins within the above preferred ranges are commercially available from Union Carbide Corporation and are sold under the brand designations POLYOX® WSR N-10 POLYOX® WSR N-80. These two resins have approximate molecular weights reported, as determined by rheological measurements, of around 100,000 g / mol and 200,000 g / mol, respectively.

Other polyethylene oxide resins available from, for example, Union Carbide Corporation within the ranges of approximate molecular weight given above are sold under the trade designations WSR N-750, WSR N-3000, WSR-3333, WS 205, WSR. -N-12K, WSR-N-60K, WSR-301, WSR Coagulant, WSR-30 (See POLYOX®; Water-Soluble Resins, Union Carbide Chemica & Plástic Company, Inc., 1991, which is incorporated herein by reference in its entirety). Both the polyethylene oxide powder and the polyethylene oxide pellets can be used in this invention since the physical form of the polyethylene oxide does not affect its behavior in the molten state for the grafting reactions. This invention has been demonstrated by the use of polyethylene oxide in powder form as supplied by Union Carbide. However, the polyethylene oxide resins that are to be modified can be obtained from other suppliers and in other forms, such as pellets. The polyethylene oxide resins and the modified compositions may optionally contain various additives such as plasticizers, rheology modifying process aids, antioxidants, ultraviolet stabilizers, pigments, dyes, slip additives, anti-block agents, etc., which can be added before or after the modification.

A variety of the vinyl pol monomers may be useful in the practice of this invention. The term "monomer (s)" as used herein includes monomers, oligomers, polymers, mixtures of monomers, oligomers and / or polymers and any other reactive chemical species which are capable of covalent bonding with the parent polymer, polyethylene oxide. Ethylenically unsaturated monomers containing a polar functional group, such as hydroxyl, carboxyl, amino, carbonyl, halo, thiol, sulphonic, sulfonate, etc., are suitable for this invention and are desired. The desired ethylenically unsaturated monomers include acrylates and methacrylates. Ethylenically unsaturated and particularly desirable monomers containing a polar functional group are 2-hydroxyethyl methacrylate (hereinafter HEMA) and poly (ethylene glycol methacrylates) (hereinafter PEG-MA) A particularly desirable poly (ethylene glycol) methacrylate is poly (ethylene glycol) ethyl ether methacrylate However, it is expected that a wide range of polar vinyl monomers will be able to impart similar effects as 2-hydroxyethyl methacrylate and poly (ethylene glycol) methacrylates to polyethylene oxide and be monomers The amount of polar vinyl monomer in relation to the amount of polyethylene oxide can vary from about 0.1 to about 20 percent by weight of monomer to the weight of the polyethylene oxide. The monomer should exceed 0.1 percent by weight in order to sufficiently improve the processing of polyethylene oxide. monomer should be at the lower end of the above-described range in order to decrease costs. A range of graft levels is shown in the examples. Typically, the monomer addition levels were between 2.5 percent and 15 percent of the weight of the base polyethylene oxide resin.

This invention has been demonstrated in the following examples by the use of PEG-MA and HEMA as the polar vinyl monomers. Both PEG-MA and HEMA were supplied by Aldrich Chemical Company. The HE A used in the examples was designated with the catalog number Aldrich 12,863-5 and the PEG-M was designated with the catalog number Aldrich 40,954-5. E PEG-MA was a poly (ethylene glycol) ethyl ether methacrylate having a number average molecular weight of approximately 24 g / mol. The PEG-MA with a number average molecular weight higher or lower than 246 g / mol is also applicable for this invention. The molecular weight of PEG-MA can vary up to 50,000 g / mol. However, the lower molecular weights are preferred for the faster graft reaction rates. The desired molecular weight range of the monomers is from about 246 to about 5,000 g / mol and the desired range is from about 246 to about 2,000 g / mol. Again, it is expected that a wider range of polar vinyl monomers as well as a broad range of molecular weights of monomers will be capable of imparting effects similar to polyethylene oxide resin and will be effective monomers for grafting and modification purposes.

A variety of primers may be useful in the practice of this invention. When the graft is achieved by means of the application of heat, as in the reactive extrusion process, it is desirable that the initiator generates free radicables through the application of heat. Such initiators are generally mentioned as thermal initiators. For the initiator to function as a useful source of radicals for grafting, the initiator must be easily and commercially available, it must be stable at room temperature or under refrigerated conditions, and generate radicals at reactive extrusion temperatures.

Compounds containing a 0-0, S-S or a N = N bond can be used as terminator primers. Compounds containing O-O bonds, peroxides are commonly used as initiators for polymerization. Commonly used peroxide initiators tale include: alkyl, dialkyl, diaryl and arylalkyl peroxides, such as cumyl peroxide, T-butyl peroxide, 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-butyl peroxy) -hexin -3 and bis (at-butyl peroxyisopropylbenzene); acyl peroxides, such as acetyl peroxide and benzoyl peroxides; hydroperoxides such as cumyl hydroperoxide, t-butyl hydroperoxide, p-methane hydroperoxide, pinane hydroperoxide and eumenohydroperoxide peresters or peroxyesters such as t-butyl peroxypivalate, t-butyl peroctoate, t-butyl perbenzoate, 2,5-dimethylhexyl -2, 5 di (perbenzoate) and t-butyl di (pereftalate); alkylsulfonyl peroxides; dialkyl peroxymonocarbonates; dialkyl peroxydicarbonate; diperoxy ketals; ketone peroxides such as cyclohexanone peroxide and methyl ethyl ketone peroxide Additionally, azo compounds, such as 2,2'-azobisisobutyronitrile abbreviated as AIBN, 2,2'-azobis (2,4-dimethylpentanenitrile) and 1,1'-azobis (Cyclohexanecarbonitrile can be used as the initiator.) This invention has been demonstrated in the following examples by the use of a liquid organic peroxide initiator available from Elf Atochem Nort America, Inc., of Philadelphia, Pennsylvania, sold under the trade designation LUPERSOL. ® 101. LUPERSOL® 101 is a free radical initiator and comprises 2,5-dimethyl-2,5-di (t-butylperoxy) hexane Other initiators and other kinds of initiators of LUPERSOL® can also be used, such as LUPERSOL®. ® 130.

A variety of reaction vessels may be useful in the practice of this invention. The modification of the polyethylene oxide can be carried out in any container provided that the necessary mixing of the polyethylene oxide, the monomer and the initiator is achieved and sufficient thermal energy is provided to effect the grafting. Desirably, such containers include any suitable mixing device. , such as Brandender Plasticorde Haake extruders, single or multiple screw extruders, any other mechanical mixing devices, which can be used to mix, combine, process or manufacture polymers. In a desired embodiment, the reaction device is a counter-rotating twin screw extruder, such as a Haake extruder, available from Haake 53 West Century Roa of Paramus, New Jersey 07652 or a counter-rotating gemel screw extruder, such as the combination extruder twin screws ZSK-30 manufactured by Werner & Pfleiderer Corporation of Ramsey, New Jersey. It should be noted that a variety of extruders can be used to modify the polyethylene oxide according to the present invention whenever mixing and heating occur.

The ZSK-30 extruder allows multiple supply has ventilation ports and is able to produce a modified polyethylene oxide at a rate of up to 50 pounds per hour If a higher rate of modified polyethylene oxide production is desired, an extruder of commercial scale ZSK-5 manufactured by Werner &; Pfleiderer can be used. The ZSK-30 extruder has a pair of counter-rotating screws arranged parallel to the center-to-center distance between the axes of the two screws at 26.2 millimeters. The nominal screw diameters are 30 millimeters. The actual external diameters of the screws are 30 millimeters and the inner screw diameters are 21.3 millimeters. The depths of rosc are 4.7 millimeters. The lengths of the screws are 1328 millimeters and the length of the total processing section was 1338 millimeters.

The ZSK-30 extruder had 14 barrels of processing, which are consecutively numbered from 14 to the barrel of feed to the matrix for the purposes of the description. The first barrel, barrel # 1 received the polyethylene oxide and was not heated but cooled with water. The other thirteen barrels were heated. E monomer HEMA or PEG-MA was injected into barrel # 5 and the initiator was injected into barrel # 6. Both the monomer and initiator were injected through a pressurized nozzle injector, also manufactured by Werner & Pfleiderer. The order in which the polyethylene oxide, the monomer and the initiate are added is not critical and the initiator and the monomer can be added at the same time or in a reverse order. However, the order used in the following examples is desired. The die used to extrude the modified polyethylene oxide yarns has four openings of 3 millimeters in diameter, which are separated by 7 millimeters. The modified polyethylene oxide yarns were extruded on a d air-cooling band and then pelletized. The molten extruded polyethylene oxide yarns were cooled with air on a 2-foot fan-cooled conveyor belt.

Another suitable extruder as the reaction device includes a Haake extruder. The modified polyethylene oxide compositions of Examples 31, 32 and 33 suitable for the purposes of fiber manufacture were modified by means of a reactive extrusion process using a Haake extruder. The Haake extruder that was used was a twin-screw counter-rotator extruder that contained a pair of custom-made counter-rotating conical screws. The Haak extruder had a length of 300 millimeters. Each conical screw had a diameter of 30 millimeters in the supply port and diameter 20 millimeters in the matrix. The monomer and the initiate were added to the supply throat of the Haak extruder at one time with the polyethylene oxide resin.

The Haake extruder comprised six sections as follows: Section 1 comprised the forward double-lumen pumping section having a large bolt tilt and a high helix angle. Section 2 comprised a double-vane forward pumping section that has a smaller screw tilt than Section 1. Section 3 comprised a double-vane forward pumping section that has a smaller screw tilt than the second section. 2. Section 4 comprised a reverse notched pumping section and a double-vane section where a full pallet f notched. Section 5 comprised a notched forward and double-sided pumping section that contained two full pallets. And, Section 6 comprised a double-vane forward pumping section that had an average screw pitch of that of Section 1 and Section 2.

EXAMPLES Polyethylene Oxide Compositions Suitable for Film Making Examples 1-21 have been demonstrated by the use of the ZSK-30 extruder as detailed above. For the following examples, the temperatures of the extruder barrel were set at 180 ° C for all seven zones of the extruder. The screw speed was set at 300 revolutions per minute. The polyethylene oxide resin was fed into the extruder with a K-Tron gravimetric feeder with a K-Tron gravimetric feeder at a rate of 20 pounds per hour. The selected monomer and initiator were fed by the Eldex pump into the extruder at the various rates reported in Table 1. Extrusion conditions, barrel temperatures reale for the seven zones of the extruder, polymer melt temperature, pressure of melt and percent of torsional force were monitored during the reactive extrusion for each of the 20 examples and are reported in Table 2 Modified polyethylene oxide yarns were cooled by air on a cooled conveyor belt by 20-foot fan of length. The solidified yarns were then pelletized in a Conair pelletizer available from Conair of Bay City, Michigan.

The percentages by weight of the components used in the examples were calculated in relation to the weight of the base resin, polyethylene oxide, unless otherwise indicated. In the following examples, five polyethylene oxide resins of different approximate molecular weight were used and tested, the POLYOX® WSR 205 polyethylene oxide having a reported initial approximate molecular weight of 600.00 g / mol was used in Examples 1 -5, 11-13 and 20; POLYOX® WSR 12K polyethylene oxide d having a reported initial approximate molecular weight of 1,000,000 g / mol was used in Examples 6-10, polyethylene oxide POLYOX® WSR N-750 having a reported initial approximate molecular weight of 3. , 00 g / mol was used in Examples 14-16; POLYOX® WSR N-3000 polyethylene oxide having a reported approximate molecular weight of 400,000 g / mol was used in Examples 17-19; and polyethylene oxide POLYOX® WSR N-80 having a reported initial approximate molecular weight of 200,000 g / mol was used in Example 21.

Additionally, two monomers HEMA and PEG-MA several levels of monomer addition, varying as low as d 0.80 percent by weight to as high as 5.00 percent by weight of monomer to weight of polyethylene oxide resin, were used and tested in the examples. The relative amount of initiator used in the examples varied from 0.12 to 0.32 percent by weight of the initiator to the weight of the polyethylene oxide resin. The trade designation of the polyethylene oxide, the monomer and the amounts of polyethylene oxide, monomer and initiator used in the examples are listed in Table 1. Example 1 represents a control sample of an unmodified polyethylene oxide of an initial approximate molecular weight of 6,000 g / mol. The Example represents a control sample of the modified n-polyethylene oxide of an initial approximate molecular weight of 1,000,000 g / mol. Example 14 represents a control sample of the unmodified polyethylene oxide of the initial approximate molecular weight of 3,000 g / mol. Example 17 represents a control sample of unmodified polyethylene oxide of an initial approximate molecular weight of 400,000 g / mol. Example 20 represents a comparative example of polyethylene oxide of the initial approximate molecular weight of 600,000 g / mol modified only by the addition of the initiator without the monomer. And Example 21 represents a comparative example of modified polyethylene oxide of an initial approximate molecular weight of 200.0 g / mol.

Although the invention has been demonstrated by the examples, it is understood that the polyethylene oxide, the polar vinyl monomer, the initiator and the conditions may vary depending on the type of modified polyethylene oxide composition and the desired properties.

Table 1 Components and Process Conditions of the Examples The current processing conditions during the extrusion of the examples of modified polyethylene oxide and n modified in Table 1 were recorded and reported in Table 2. The extrusion runs were made for each one of the examples of extrusion-reactive 2-5 and 7-5 and are reported as the second values 2 '-5' and 7 '-10', respectively. T-. T7 represent the current barrel temperatures of the seven extruder zones during the extrusion of the examples. corresponds to barrels # 2 and # 3, T2 corresponds to barrels # 4 and # 5, T3 corresponds to barrels # 6 and # 7, T4 corresponds to barrels # 8 and # 9, T5 corresponds to barrels # 10 and # 11, corresponds to barrels # 12 and # 13, and T7 corresponds to barri # 14, the matrix. Barrel # 1 was not heated and remained at environmental conditions.

Table 2 Observed Extrusion Conditions When unmodified higher molecular weight polyethylene oxide resins, Examples 1 and 6 were extruded under the above mentioned processing conditions, the melt pressure during extrusion of unmodified polyethylene oxide resins It was very high L Melt pressure of polyethylene oxide of molecular weight d 600, 000 of Example 1 was 1770-1810 pounds per square inch and the melt pressure of the unmodified 1,000,000 molecular weight polyethylene oxide of Example 6 was 1540-1660 pounds per square inch. The high-shear heating in the extruder caused the melting temperatures of unmodified polyethylene oxide resins to increase significantly by 24 and 29 ° C over the extruder bar temperature of 180 ° C. The melt temperature increased to 204 ° during the extrusion of the unmodified 600,000 molecular weight polyethylene oxide of Example 1 and increased to 209 ° C during the extrusion of the non-modified d 60,000 molecular weight polyethylene oxide of Example 6. These Factore contributed to cut the melt fracture and the thermal degradation during the extrusion of unmodified higher molecular weight polyethylene oxide d resins resulting in the production of undesirable threads. Undesirable threads were characterized by threads wider than those tried, broken threads, rough threads and threads connected to beads.

The top screw speed of 4 revolutions per minute and a lower production approximately 5-10 pounds per hour, the melt fracture reduced something. However, under these conditions, the degradation of the polyethylene oxide appeared to be even more severe with significantly more bubbles evolving inside the yarns as they left the matrix due to the increase in residence time in the extruder. The exiting polymer yarns had a foam-like appearance which is undesirable. Additionally, the extruder was set at 5 pounds per hour and this in an extremely low setting and is not practical for commercial applications.

For the grafting process of the modified higher molecular weight polyethylene oxide resins under the same conditions, Examples 2-5 and 7-10, the melted fracture d was not visible producing yarns with smooth surfaces The melt temperatures were significantly reduced as shown in Table 2. The grafting of the melt temperatures HEMA and PEG-MA to polyethylene powders POLYOX® WSR 205 d Examples 2-5 were in the range of 189 to 198 °. C, a reduction of 6 to 15 ° C compared to the melt temperature of the same polyethylene oxide resin without the graft d Example 1 at 204 ° C. The threads also seemed to suffer less degradation since the polymer threads contained fewer bubbles and were significantly smoother as the matrix exited. The melt temperatures for HE grafting or PEG-MA to polyethylene oxide POLYOX® WSR 12K, Examples 7-10, were also essentially reduced down to the range of 183 to 191 ° C compared to 209 ° C without grafting. Example 6 a reduction of 18 to 26 ° C. This reduction in molten temperature d also apparently reduced the lower extruder degradation, since the polymer yarns contained less bubble when leaving the die compared to the same ungrafted polyethylene oxide resin.

Examples 14 and 17 showed some melt fracture and thermal degradation, even if not as severe as observed for Examples 1 and 6. The most obvious problems with the extrusion of Examples 14 and 17 were the high melt pressure, 1379 and 1659 pounds per square inch, and the increased torque force, 33 and 33%. For the modified polyethylene oxide of Examples 15, 16, 18 and 19, the melt pressure was reduced by more than 50% in comparison to the unmodified polyethylene oxide of the same starting molecular weight and the torsional force was slightly reduced for each one from 33 down to 26-28%. The melt temperature was not reduced for these examples.

Example 20, polyethylene oxide POLYOX® WS 205 modified by the addition of only the initiator, showed a remarkable change in the melt extrusion compared to Example 1, polyethylene oxide POLYOX® WSR 205 not modified Melt pressure it was reduced from 1770-1890 pounds per square inch to 313 pounds per square inch. The torsional force was reduced from 32-36% to 26%. And, the molten temperature was reduced from 204 ° C to 198 ° C. These changes were expected to have a result primarily of the chemical degradation of polyethylene oxide in the presence of free radical initiator, the same mechanism of chemical degradation that occurred for Examples 2-5, 7-13, 15, 16, 18 and 19 However, because Example 20 was modified without the use of the monomer, the preferential reaction was crosslinking as opposed to grafting. The resulting material was filled with crosslinking gel particles, ta large as 0.5 to 1 millimeter. The gels made useless and resulting polyethylene oxide.

Cross-linked gels were not observed or were significantly reduced in both size and number for the modified polyethylene oxides of Examples 2-5, 7-13, 15-16 and 18-19. It is believed that the preferential initiate reacted with the monomer causing a split graft and chain instead of cross linking. The modified polyethylene oxide of Examples 2-5, 7-13, 15-16 and 18-1 have beneficial properties, for thermal processing and thin films and are useful for producing commercially useful items, such as personal care products. .

In general, modified polyethylene oxide Examples 2-5, 7-13, 15-16 and 18-19 exhibited a reduced melt temperature and a reduced melt pressure compared to unmodified higher molecular weight polyethylene oxide. correspondent. This allows easier and more economical processing of polyethylene oxide. The appearance of the modified extrusion-modified polyethylene oxide according to this invention is greatly improved compared to unmodified higher molecular weight polyethylene oxide. The extruded yarns of the modified polyethylene oxide according to this invention are much smoother and much more uniform compared to the extruded yarns of some of the initial unmodified polyethylene oxide. The smoothness and uniformity of the extruded threads of the modified polyethylene oxide of Examples 2-5, 7-13, 15-16 and 18-19 is comparable to the smoothness and uniformity of the extruded polyethylene oxide threads of molecular weight. approximate much lower per with higher mechanical properties of higher molecular weights.

Gel Permeation Chromatography Analysis The number average molecular weight (1 ^), the weight average molecular weight (M, the z-average molecular weight (M and the IVL / M polydispersity index of the examples f determined by gel permeation chromatography (here hereinafter GPC) The Gel Permeation Chromatography analysis was conducted by American Polymer Standard Corporation of Menton, Ohio for the examples in Table 1 also for polyethylene oxide powders POLYOX® WSR 20 and POLYOX® WSR 12K unmodified and The results of the Gel Permeation Chromatography analysis are reported in Table 3. The first two rows of Table 3 report the results of Gel Permeation Chromatography analysis for the powders of POLYOX® WSR 205 and POLYOX WSR 12K before extrusion Examples 1 and 6 are the results for the Ge Permeation Chromatography analysis of polyethylene oxides POLYOX® WSR 205 and POLYOX® WSR 12 extruded and non-modifi of Examples 1 and 6 of Table 1 respectively. That is, Examples 1 and 6 depict the extrusion of polyethylene oxide resins POLYOX® given above at 180 ° C, at 300 revolutions per minute and 20 pounds per hour in the ZSK-30 extruder with the additions of any monomer or initiator. The other example numbers correspond to the respective example numbers in Table 1.

Table 3 Polydispersity and Molecular Weight indices Significant reductions in molecular weight and polydispersity indices were observed after the reactive extrusion of the polyethylene oxide with the monomer and the initiator of Examples 2-5 and 7-10 as compared to the extruded polyethylene oxide and not modified from Examples 1 and 6. Along with changes in molecular weight and polydispersity index, a vast improvement in processability was observed. The most notable change in the molecular weight distribution was observed in the reduction of the polydispersity index, which was reduced from 12.52 for the unmodified polyethylene oxide from 600,000 g / mol down to 4.07 5.16 for the same starting polyethylene oxide modified according to the invention and from 14.29 for the unmodified polyethylene oxide from 1,000,000 g / mol down to 4.07 4.84 for the same modified starting polyethylene oxide according to the invention.

The GPC analysis was not carried out for Examples 11-20. However, it is believed that the modified polyethylene oxides of Examples 11-13, 15-16 and 18-1 will have reduced average molecular weights and polydispersity indices in comparison to the corresponding modified n-polyethylene oxides.

Differential Exploration Calorimetry Analysis of Thermal Properties The modified and modified polyethylene oxide compositions of Examples 1-19 were analyzed by Differential Scanning Calorimetry (DSC) to determine the differences in thermal properties between modified and unmodified polyethylene oxide resins. Example 2 was not analyzed by Differential Scanning Calorimetry because the polyethylene oxide of Example 20 was modified without the addition of a monomer was determined as not being useful for the manufacture of films. The melting points (Tm) the enthalpy of the melt values (? H) for Examples 1-are reported in Table 4.

Table 4 Thermal Properties The melting points as determined by differential scanning calorimetry of the modified polyethylene oxides of Examples 2-5 and 11-13 are lower than for the initial unmodified polyethylene oxides d Example 1. Similarly, decreases, at the melted points were observed for the modified polyethylene oxides of Examples 7-10 in comparison to the initial unmodified polyethylene oxide of Example 6, for the modified polyethylene oxides of Examples 15 and 16 as compared to unmodified polyethylene oxide of Example 14 and for the modified polyethylene oxides of Examples 18 and 19 compared to the initial unmodified polyethylene oxide of Example 17. Those measured decreases in the melting points of the modified polyethylene oxides are further evidence of the modification and are beneficial for thermal processing Melting Rheology Melt rheology curves for resin compositions of approximate initial molecular weight d 600,000 g / mol unmodified, Example 1, and modified, Example 2-5 are given in Figure 1. Molten rheology curves for the compositions of initial approximate molecular weight resin of 1,000,000 g / mol unmodified, Example 6 and modified, Examples 7-10, are given in Figure 2. Melt rheology curves for resin compositions of initial approximate molecular weight of 600,000 g / mol unmodified Example 1, and modified, Examples 11-13, were provided in Figure 4. The melt rheology curves for the initial approximate molecular weight compositions of 300.00 g / mol unmodified, Example 14, and modified, Examples 15 and 16 were provided in Figure 5. Molten rheology curves for resin compositions of approximate initial molecular weight of 400,000 g / mol unmodified, Example 17, modified, Example 18 and 19, were provided in Figure 6.

The results show that the melt viscosities of the modified polyethylene oxides are significantly reduced at low cut-off rates, of 50-500 s "1, than the melt viscosities of unmodified polyethylene oxide. For example, the melt viscosity of the polyethylene oxide resin of approximate molecular weight of 1,000,000 12K n modified is 6.433 Pa * s to 50 s "1 and the melt viscosity of the same 12K resin modified with 5% PEG-MA and 0.32 of initiator L101 is 2,882 Pa * s at the same cut rate of 5 s "1. This is a reduction in melt viscosity of 55%.

However, at higher cutting rates, especially 500-2000 s "1, the melt viscosities of modified polyethylene oxide appear to be comparable to or greater than the melt viscosities of the modified polyethylene oxide n. modified resin 12 was 275 Pa * s 2000 s "1 and the melt viscosity of the same 12K resin modified with 5% PEG-MA and 0.32% d L101 initiator is 316 Pa * s the same cutting rate 2.00 s "1. This is an increase in the melt viscosity of 15%.

In general, the inclinations of the apparent viscosity against the cutting rate decreased after the modification.

NMR analysis The modified polyethylene oxide of the examples was analyzed by NMR spectroscopy. The results of this analysis confirmed that the modified polyethylene oxide actually contained HEMA or PEG-MA units grafted as side chains on the polyethylene oxide column. For NMR spectroscopy, it was determined that the polyethylene oxide produced in Examples 2-5, 7-13, 15-16 and 18-19 contained 0.6 to 2.58 percent of grafted HEMA or PEG-M side chains and 0 to 2.39 percent of unreacted HEMA or ungrafted PEG-MA.

Film Setting Process The modified extruded polyethylene oxide resins of Examples 1, 6, 14, 17 and 21 were pelletized and attempts were made to process these unmodified extruded polyethylene oxide resins into thin films for film processing., a Haake twin counter-rotating screw extruder was used with either a 4-inch or 8-inch wide film holder. Temperature profile for the Haake extruder heating zones was 170, 180, 180 and 190 ° C. The screw speed was adjusted in the range of 15-50 revolutions per minute depending on the thickness of the film tried. Screw speed and winding speed were adjusted so that a film with a thickness within the range of 2 4 mils was produced. The process was stabilized so that the film samples could be collected and observed. The extruded films were collected on a cooled coiling roll maintained at 15-20 ° C.

The Haake extruder that was used to forge the films of the polyethylene oxide compositions was a twin counter-rotating screw extruder that contained a pair of counter-rotating taper screws tailored with the 4-inch-wide film matrix fastener. The Haake extruder comprised six sections as follows: Section 1 was composed of a forward double-vane pumping section that had a large screw tilt and large helix angle. Section 2 comprised a double-vane forward pumping section that had a smaller slant tilt than Section 1. Section 3 comprised a double vane forward pumping section having a smaller screw tilt than Section 2. Secció 4 comprised a section of pumping in reverse of notch of double pallet where a complete pallet was notched. The Section comprised a section of forward pumping and double-palette that contained two complete pallets. And the Section comprised a double-pallet forward pumping section that had an intermediate screw pitch to that of Section 1 and Section 2. The extruder had a length d 300 millimeters. Each conical screw had a diameter of 3 millimeters in the supply port and a diameter of 2 millimeters in the matrix. Even though the extruder mentioned above is described in detail, it should be noted that a variety of extruders and apparatus for processing the polyethylene oxide film can be used.

The modified extruded polyethylene oxide resins of Examples 1 and 6 were not capable of being processed into thin films. Only thick sheets with a thickness greater than about 7 thousandths of an inch are capable of being produced. Even these thick sheets exhibited a severe melt fracture. The stiffness and molten fracture of the leaves gave the leaves an undesirable closure-like appearance with sharp teeth on the edges. The unmodified polyethylene oxide resins are not capable of being thermally processed into thin films under normal processing conditions.

The modified extruded polyethylene oxide resin of Example 14, which had the lowest weight of the high molecular weight polyethylene oxide resins tested, was the most processable of the unmodified higher molecular weight polyethylene oxides. However, the unmodified polyethylene oxide of Example 14, the polyethylene oxide POLYOX® WSR N-750 with an approximate initial molecular weight of 300,000 g / mol was very difficult to process on a uniform sheet d around 4 mils. All attempts to process a film less than 4 thousandths of an inch thick resulted in breakage, emergence, and uneven film. The film of minimum thickness that was capable of being processed from the polyethylene oxide of 400,000 g / mol unmodified from Example 17 was only about 5 mils d inch.

The polyethylene oxide composition of the Example can only be processed in a film of about 3- thousandths of a thickness. However, the 3-4 mil films of the polyethylene oxide of Example 20 contained numerous fish eye holes. Even though the torsional force and pressure during processing of the films of Example 2 were low, the films contained so many gel inclusions that the gel inclusions propagated the effects in the films. At less than 3-4 thousandths of an inch, the fish eye holes became so large that they interconnected and caused breaks in the films.

The unmodified polyethylene oxide only that was capable of being processed in this film was polyethylene oxide POLYOX® WSR N-80 of a low molecular weight of 200.00 g / mol of Example 1. However, the processed films of Unmodified low molecular weight polyethylene oxide of Example 21 possess insufficient mechanical properties, such as low tensile strength and low ductility, also exhibit an increased brittle element during storage under ambient conditions. Additionally, the processed film of the unmodified polyethylene oxide of Example 21 contained undesirable grainy particles. These deficiencies made the modified polyethylene oxide resins impractical for commercial use in personal care products.

In contrast, the films were successfully processed from the modified and extruded polyethylene oxide compositions. The films were processed by co-melting the polyethylene oxide compositions of Examples 2-5, 7-13, 15-16 and 18-19 using the same apparatus processing conditions as tried for the processed films of the oxide compositions. modified polyethylene n, Examples 1, 6, 14, 17, 20 and 21, as detailed above. Uniform films about 3 thousandths of an inch thick were made. The screw speed, torsional force, pressure and die temperature for the processing of the films of the examples were measured and the averages of the measurements were reported in Table 5.

Table 5 Film Processing Conditions Attempts were made to process the films with acceptable solid state properties of the unmodified higher molecular weight polyethylene oxide resins These attempts were made using the unmodified polyethylene oxide POLYO WSR 205 and the unmodified POLYOX® WSR 1 polyethylene, approximate molecular weights of 600,000 g / m and 1,000,000 g / mol, respectively. The polyethylene oxide of POLYOX® WSR 12K could not be processed in a film. P, therefore, the torsional force and pressure data were not collected for polyethylene oxide POLYOX® WSR 12 Example 6 of Table 5. Polyethylene oxide of unmodified POLYOX® W 205 could not be extruded at lower screw speeds . The observed pressure and torsional strength during the film processing of the POLYOX® WSR 205 polyethylene oxide compositions of Examples 2-5 was dramatically reduced compared to unmodified polyethylene oxide POLYOX® WSR 205, Example 1. Resins of unmodified higher molecular weight polyethylene oxides were found to be impractical for thin film extrusion due to poor melt processing and lack of ability to be processed into films less than about 7 mils in thickness. Therefore, unmodified high molecular weight polyethylene oxide resins are impractical for melt processing.

In contrast, the modified polyethylene oxide compositions were capable of being processed into films with thicknesses of less than 0.5 mils without breaking or tearing. This is a significant improvement over the thicknesses of about thousandths of an inch for the films of the unmodified higher molecular weight polyethylene oxides of Example 1 and 6. The grafting of the polar vinyl monomers the polyethylene oxide transforms the melt properties the processing, improving the processability by increasing the resistance of the melt and the casting of polyethylene oxide melt, thus allowing the thin films to be easily and quickly processed. This is also an improvement over the difficulties of processing a film less than one thousandth of an inch of unmodified low molecular weight polyethylene oxide such as Example 21 which possessed desirable processing conditions of low torsional force, pressure and matrix temperature but they lack the desirable mechanical properties in a usable film.

The modified polyethylene oxide compositions of Examples 11-13 with lower monomer addition levels processed comparably to the modified polyethylene oxide compositions of Examples 2-5 also exhibited a reduced torsional force and depressed during processing in comparison to the unmodified polyethylene oxide processed under similar conditions. The modified polyethylene oxide compositions of Examples 15 and 16 also exhibited a significantly reduced torsional force and pressure and a slightly reduced matrix temperature during processing as compared to polyethylene oxide of Example 14 when processed under similar conditions. Generally, the melt viscosity during the film processing of the modified polyethylene oxide compositions was reduced and the matri pressure was reduced by more than 50%.

The very thin films were capable of being processed from the modified polyethylene oxide compositions of Examples 15 and 16, exhibiting excellent processing. In contrast, unmodified POLYOX® WSR N 750 polyethylene oxide that had an approximate molecular weight of 300,000 g / mol was not capable of being processed in a film d less than 4 mils in thickness and would break up and emerge. would uneven in thicknesses during attempts to process the films to 4 mils of thickness Similarly, the modified polyethylene oxide compositions of Examples 18 and 19 also exhibited a significantly reduced torsional force and pressure and a slightly reduced matrix temperature during processing in comparison to the modified n-polyethylene oxide of Example 17 when processed under similar conditions and capable of being processed into thin films exhibiting excellent processability. In contrast, unmodified POLYOX® WSR N-3,000 polyethylene oxide d Example 17 was not capable of being processed in a 5 mil thick film and produced in 5 mil films with similar serrated serrated edges. to those observed from Example 1.

In general, the modified polyethylene oxide films did not stick to the chill roll. The modified polyethylene oxide films produced were smooth and smooth and did not contain any grainy particles, as did the unmodified low molecular weight polyethylene oxide extruded films of Example 21. Films produced from the modified polyethylene oxide compositions. generally they have better smoothness, smoothness and greater clarity than similarly produced films of modified polyethylene oxide compositions generally have better smoothness and clarity than similarly produced films of modified n-polyethylene oxide compositions. Therefore, it has been found that the films of modified polyethylene oxide compositions exhibited significantly improved film processing and can be more easily and economically processed into thin films useful for personal care applications in contrast films of polyethylene oxide compositions. modified.

Stress Properties of Modified Polyethylene Oxide Films Stress tests were carried out on the films produced from the compositions of Examples 2-13, 15, 16, 18-20 and of the POLYOX® WSR N-polyethylene oxide resin as detailed above. The tension properties of each of the films was tested and the direction of the machine (MD) and in the transverse direction (CD) were measured and are presented in Table 6.

Table 6 Film Stress Properties The processed films of the unmodified POLYOX® WSR N-80 polyethylene oxide resin of Example 2 possessed low breaking elongation values. The mechanical properties of the POLYOX® WSR N-80 polyethylene oxide film were tested and measured within 24 hours of film processing and are expected to decrease considerably with aging. Only coarse films of not less than 7.4 mils thick are capable of being processed from the unmodified POLYOX® WSR 12 polyethylene oxide resin of Example 6. Transverse direction properties could not be measured for the films of Example 6 due to the great variations in the thicknesses in the transversal direction of the films.

The mechanical properties of the processed films of four polyethylene oxide compositions Examples 2-5, modified from the polyethylene oxide resins had a molecular weight of 600,000 g / mol before the modification were tested. These films have high breaking elongation values ranging from 570 to 736 percent. These modified polyethylene oxide compositions have molecular weights and molecular weight distributions similar to the molecular weight and molecular weight distribution of the polyethylene oxide POLYOX® WSR N-80 but have significantly improved mechanical properties compared to the processed films of the Polyethylene oxide resin of unmodified low molecular weight. It is believed that these improved mechanical properties are obtained, at least in part, are the increased chain interactions between the modified polyethylene oxide chains introduced by the grafting of HEMA and PEG-MA threads into the polyethylene oxide. Additionally, it is believed that the grafted polar groups resulted in hydrogen bonding. between the neighboring polyethylene oxide chains linking the chains in both solid and molten states.

Even the modification of polyethylene oxide resins with low levels of monomers produces improved mechanical properties. This was demonstrated by the high elongation measurements at the break, peak stress and breaking energy observed for the films of Examples 11, 12 and 13. The grafting, even at low levels, improved the fundamental properties of the polyethylene oxide, allowing for Both thin films are processed from polyethylene oxide In general, processed films of the modified polyethylene oxide compositions were found to have improved mechanical properties over similarly processed films of conventional resins. Modified polyethylene oxide films showed dramatic improvements in tensile properties, greater than 600 percent in tension and 200 percent in effort in the direction of the machine and greater than 1,400 percent in tension and 200 percent in effort in the transverse direction. Additionally, the films produced from the modified polyethylene oxide compositions were observed to have balanced properties in the direction of the machine against the transverse direction. These films exhibited improved peak to break and break energy values. More importantly, these films have reduced modulus values which demonstrate their improved flexibility compared to unmodified polyethylene oxide films. The improved flexibility of films containing the modified polyethylene oxide d is particularly desirable for disposable applications with water discharge specifically for disposable personal care products with water discharge.

Quantitative FT-IR Analysis Fourier transformation infrared spectroscopy analysis (FT-IR) was carried out on thin processed films of the compositions of Examples 1, 3 5. The spectra obtained from this analysis are shown in Figure 3. The lower line is the spectr observed for Example 1, polyethylene oxide of approximate molecular weight of 600,000 g / mol extruded and unmodified. The middle line is the spectrum observed for Example 3, the polyethylene oxide of approximate molecular weight of 600.0 grams / mole grafted with 5 percent HEMA. And the upper line is the spectrum observed for Example 5, the polyethylene oxide of approximate molecular weight of 600,000 g / m grafted with 5 percent PEG-MA.

The small peaks observed at approximately 1,725 centimeters "1 in the upper and middle spectrum of l Examples 5 and 3 respectively are the absorption peaks of PE MA and HEMA respectively.This absorption peak approximately 1,725 centimeters" 1, was not observed for oxide of unmodified polyethylene as shown in the lowest specimen of Figure 3.

Crystal Morphology The unmodified POLYOX® WS 205 polyethylene oxide film having an approximate molecular weight initiates reported 600,000 g / mol of Example 1 and a film produced from a modified sample of the same initial resin was analyzed using polarized light microscopy. In addition to being of a greater thickness, the unmodified film possessed spherulite crystals greater than the film produced from the modified polyethylene oxide under the same processing conditions. The spherulites in the unmodified sample were observed to be of the order of 20 to 50 microns d, while the spherulites in the modified sample n were observable under the same amplification and are believed to be in the order of less than 1 miera in size. The crystal structure of the films changed dramatically due to grafting. It is believed that the improved mechanical properties of the films containing the modified polyethylene oxide s produce at least in part from the changes in the crystal morphology. Additionally, the resistance of the modified films to the physical aging is expected to improve as a result of the improvement observed in the crystal structure.

COMPARATIVE EXAMPLE A A polyethylene oxide resin having a molecular weight of about 200,000 g / mol was processed through a Haake extruder under similar conditions as the following modified examples of the invention for comparative purposes and to demonstrate that polyethylene d-oxide resins do not conventional modified can not be processed with fiber melt. The unmodified polyethylene oxide resin of molecular weight of 200,000 g / mol was used for this comparative example was obtained from Planet Polymer Technologies. The resin obtained from Planet Polymer Technologies was in pellet form and was composed of POLYOX® WSR N-80 polyethylene oxide resin manufactured by Union Carbide Corporation.

For processing, the extruder bar temperatures were set at 170, 180 and 180 degrees centigrade for the first, second and third heating zones respectively and 190 degrees centigrade for the matrix. Screw speed was set at 150 revolutions per minute. Polyethylene oxide resin was fed to the extruder at a rate of about 5 pounds per hour. No monomer or initiator was added to the polyethylene oxide resin of Comparative Example A. The unmodified polyethylene oxide extruded under the above-mentioned conditions was cooled in air and pelleted for later use. Attempts continued to process with melt the unmodified polyethylene oxide of Comparative Example A in the fibers. Because the molten polyethylene oxide of Comparative Example A had too low a melt elasticity and a very low melt strength to allow attenuation of the polyethylene oxide melt, the fibers could not be melt processed using the spinning techniques of conventional fiber, such as the Lurgi gun, the starter gun and the free fall. The melted polyethylene oxide extruded from the spin plate s easily broke and did not allow the unmodified polyethylene oxide resin to be pulled into fibers. Only threads of about 1 to 2 millimeters in diameter were able to be produced from the unmodified polyethylene oxide of Comparative Example A.

COMPARATIVE EXAMPLE B A polyethylene oxide resin having a molecular weight of about 100,000 g / mol was processed through a Haake extruder under the same conditions of Comparative Example A. The molecular weight polyethylene oxide resin of 100,000 g / mol which was used for this Comparative Example B was obtained from Planet Polymer Technologies was in the form of a pellet and was combined with the POLYOX WSR N-10 resin manufactured by Union Carbide Corporation. Also, attempts were made to melt-process the unmodified polyethylene oxide of Comparative Example B into fibers. Fibers of diameters of less than about 100 micrometer can not be processed by melt of the polyethylene oxide resin of 100,000 g / molecular weight. mol not modified using conventional fiber spinning techniques. Even though the melt can only be pulled very slowly and the melt is easily broken, making commercial production of impractical polyethylene oxide fibers. Thus, Comparative Examples A and B demonstrated that the unmodified polyethylene oxide resins of the prior art can not be processed with fiber melt.

EXAMPLES Polyethylene Oxide Compositions Suitable for Fiber Manufacturing Polyethylene oxide resin POLYOX® WSR N-1 of 100,000 g / mol was fed to a Haake extruder at 5.3 pounds per hour along with 0.53 pounds per hour of PEG-MA monomer 0.026 pounds per hour of free radical initiator LUPERSOL 101 , Example 31 of Table 7. POLYOX WSR N-80 polyethylene oxide of 200,000 g / mol was modified in the same manner with the same monomer and initiator at the same relative amounts, Example 32 in Table 7. When the monomer and initiator were added to the polyethylene oxide base resins during extrusion, the melt elasticities and the melt strengths of the polyethylene oxide resins were visibly improved. These modified polyethylene oxide compositions were collected in volume and then ground into a powder for further fiber processing.

The melt viscosities of the polyethylene oxide resins were observed to have been substantially reduced by the modification with the monomer and the initiator. The melt viscosity of the modified and unmodified polyethylene oxide resins of 200,000 grams / mol was measured at various cutting rates and are presented in Figure 7. Melt viscosity of the modified polyethylene oxide resin, WSR N-80, was 319 Pascal * seconds (hereinafter Pa * s) to 1,000 seconds "1. In contrast, the melt viscosity of the same polyethylene oxide resin is modified by the addition of the monomer and the initiator, Example 32, f reduced to 74 Pascals * second at the same cutting rate.

The melt viscosities of Comparative Example A and Example 32 were determined by means of melting rheology tests carried out on a Goettfert Rheograph 2003 capillary ream. The rheometer was operated with a matrix of 30/1 millimeter in length / diameter at 195 Celsius grad. The apparent melt viscosities measured Pascals * seconds were determined at cutoff rates of 50, 100, 200, 500, 1,000 and 2,000 seconds "1 of developed rheology curves for each of the polyethylene oxide compositions. for the two respective polyethylene oxide compositions are presented in Figure 7. Over the entire range of the cor-rates tested, the modified polyethylene oxide exhibited lower apparent viscosities than the polyethylene oxide of which this modified f.

The modification by grafting the monomer onto the polyethylene oxide provided a drop of 77 pcent in the melt viscosity. The reduced viscosity provided by the modification of polyethylene oxide has to the possible fiber spinning of polyethylene oxide. The fibr of very small diameters, in the range of 20-30 micrometers, were able to be continuously pulled from the polyethylene oxide resins modified above. The fibers within this diameter range are useful for making non-woven fibers linked with yarn. Polyethylene oxide fibers and fabrics are disposable with water discharge and water dispersible and can be used as components in disposable personal care products with water discharge.

When the addition of monomer and initiator was stopped during the extrusion process, the properties of the polyethylene oxide resins reverted to their previous values and the fibers could not be pulled from the unmodified polyethylene oxide melt. This demonstrated that the modification occurs and improves the properties of polyethylene oxide which is critical for fiber manufacture and commercial viability.

Other examples of the modified polyethylene oxide resins were produced to further demonstrate the invention. These other examples of the modified polyethylene oxide resins were produced by varying the molecular weights, 100,000 and 200,000 g / mol, and the suppliers of polyethylene oxide, Union Carbide and Planet Polym Technologies Inc., (a combiner, from here hereinafter abbreviated PPT); the monomers, 2-hydroxyethyl methacrylate and poly (ethylene glycol) the ethyl ether methacrylate described above and the amount of monomers; the quantity of the initiator of LUPERSO 101; and the extruder. The various parameters used in the various examples are listed in Table 7 given below. The percentage by weight of the components used in the examples was calculated in relation to the weight of the base resin, polyethylene oxide, unless indicated otherwise.

Table 7 Components and Processing Conditions of the Examples Examples 31, 32 and 33 were processed in a Haake extruder under similar conditions as described in the comparative examples mentioned above. The exact same extruder design, temperatures and screw speed were used. However, Examples 31, 32 and 33 included addition of monomer and initiator to the polyethylene oxide resin in order to modify said polyethylene oxide resin. The listed amounts of monomer and initiator d were added to the Haake extruder feed throat contemporaneously with the polyethylene oxide resin. The Examples 34, 35, 36 and 37 the ZSK-30 extruder detailed above was modified. The heated fourteen barrel of the ZSK-30 extruder consists of seven heating zones. For the modification of Examples 34-37, seven zones of the extruder ZSK-30 were all set at 180 degrees centigrade and the screw speed was set at 30 revolutions per minute. The respective monomer, HEMA or PEG-as listed in Table 7, was injected into the barrel number and the initiator was injected into barrel number 5. Both the monomer and the initiator were injected through a nozzle injector with pressure at the same rate. The order in which polyethylene oxide, monomer and initiator n are added is critical. The initiator and the monomer can be added at the same time or in the reverse order. It should be noted that the order used in the examples is preferred.

Although the invention has been demonstrated by the examples, it is understood that the polyethylene oxide, the polar vinyl monomer, the initiator and the conditions can be varied depending on the type of modified polyethylene oxide composition and the desired properties.

Fiber Manufacturing Process Attempts were made to melt the processed fibers of the polyethylene oxide compositions of Examples 31, 32 and 33 using conventional processing techniques. The modified polyethylene oxide compositions of Examples 31, 32, and 33 were processable co-melted into fibers by a spin-linked process of research scale in contrast to the unmodified polyethylene oxide compositions of Comparative Examples A and which they could not be extruded in a melt with a suitable melt strength and an elasticity for processing into fibers. The melt processability of the modified polyethylene oxide resins was demonstrated by means of a conventional spinning bonding process on an experimental spinning line comprising a twin screw extruder, a melt metering pump and a spinning plate. The process linked with spinning was used to spin the fibers but was not used to join the fibers.

Free falling fibers and hand pulled fibers or by an initiating gun on a fiber spinning line were produced from the modified polyethylene oxide composition of Example 31. Free falling fibers and fibers pulled by a Lurgi gun and by a gun initiated on a fiber spinning line were produced from the polyethylene oxide composition of Example 32. Free-falling fibr and fibers pulled by a gun initiated on the fiber spinning line were produced from modified polyethylene oxide composition. of Example 33 Although no attempts have been made to process fibers of the modified polyethylene oxide compositions of Examples 34, 35, 36 and 37, it is expected that the modified polyethylene oxide compositions will be processable with melted fibers. The appearance of the modified and extruded polyethylene oxide compositions of Examples 34, 35, 3 and 37 was similar to the appearance of Examples 31, 32 and 33 exhibiting lower viscosities and one more tack material. These reduced melt viscosities made it possible fiber spinning of modified polyethylene oxide compositions and without particularly advantageous for the manufacture of commercial fiber especially when using methods q require melt processing.

Some of the modified polyethylene oxide compositions were converted into melt blown fibers. The fibers retained the same solubility to beneficial agar as unmodified polyethylene oxide. It is property is particularly desirable for disposable applications with water discharge. The fibers produced by the spin-linked process were also soluble in water and p are both easily disposable with water discharge.

Physical Test and Characterization of Fibers Stress tests were carried out on fibers produced from the modified polyethylene oxide compositions of Examples 31, 32 and 33. The tests were carried out using the Sintech l / D voltage tester available from MTS Systems Corporation of Machesny. Park, Illinois. The diameter of the fiber was measured before the test and then the fiber was tested with a 1 inch gap separation and a crosshead speed of 500 millimeters / minute. The diameters and tensile properties of the fibers produced from the modified polyethylene oxide resins of Examples 31, 32, and 3 were measured and reported in Table 8 given below. The fibers made of polyethylene oxide of 200,000 g / mol were significantly more docile than those made of 100.00 g / mol. For fibers made from the same base resin d of polyethylene oxide of molecular weight, higher levels of PEG-MA, for example 10 percent by weight, led to a significantly increased ductility of the fibers. The polyethylene oxide fibers pulled with Lurgi pistol at 10 percent addition of PEG-MA had a peak tension of 7.2 MPa and an elongation at break of 648 percent. The tensile property values are extremely favorable for fibers derived from polyethylene oxide considering unmodified polyethylene oxide very brittle in nature.

Table 8 Stress Properties of the Fibers Produced from Examples 31, 32 and 33 GPC analysis The number average molecular weight (^), the weight average molecular weight (MJ, and the average molecular weight- (Mz) of Comparative Examples A and B and Examples 31, 3 and 33 were determined by permeation chromatography. The GPC analysis was carried out by American Polymer Standard Corporation of Mentor, Ohio From these measurements the polydispersity indices (Mw / Mn) of the respective examples were calculated.The various molecular weights and the polydispersity examples are reported in the Table 9 given below.

NMR analysis The modified polyethylene oxide composition of Examples 31, 32 and 33 was analyzed by NMR spectroscopy. The NMR spectrum 13C and XH of Example 32 are presented as Figures 8 and 9, respectively. The results of this analysis confirmed that the modified polyethylene oxide contained PEG-MA units.

The grafting levels of the modified polyethylene oxide compositions of Examples 31, 32 and 33 com were measured by NMR analysis are reported as percentages by weight of monomer by weight of polyethylene oxide base resin that were grafted to the resin of polyethylene oxide d and were reported in Table 9. The non-grafted monomer percentages of Examples 31, 32 and 33 are in the similar manner reported in Table 9.

Table 9 Chemical Properties of Comparative Examples A and B and Modified Polyethylene Oxide Compositions of Examples 31, 32 and 33 The molecular weights of the examples of modified polyethylene oxide d are significantly different from the corresponding unmodified polyethylene oxide resin. Significant reductions in molecular weight and polydispersity indices were observed after the reactive extrusion of the polyethylene oxide with the monomer and the initiator compared to the unmodified extruded polyethylene oxide of the comparative examples. The weight average molecular weight of polyethylene oxide N-80 dropped 148,100 g / mol for polyethylene oxide N-80 not modified but similarly processed from Comparative Example A to 97.2 g / mol for 5% polyethylene oxide grafted with N-80 d Example 31 and to 109,300 g / mol for the N-10% grafted polyethylene oxide of Example 32. Similarly, the weight average molecular weight of the N-10 polyethylene oxide dropped from 115.90 g / mol for the unmodified polyethylene oxide N-10 of Comparative Example B at 90,600 g / mol for 10% of the grafted polyethylene oxide N-10 of Example 33. Therefore, the modification of the polyethylene oxide resins produced a significant reduction in the weight average molecular weight. However, the number average molecular weight was not greatly affected by the modification thus producing a significant decrease in the polydispersity index and, therefore, a narrower molecular weight distribution.

The fundamental changes in the modified polyethylene oxide produced by the chemical graft have profound and unexpected effects on the physical properties of the melt processing of the polyethylene oxide as demonstrated here and discussed above. The narrower molecular weight distributions of the modified polyethylene oxide compositions result in improved solid state and melt properties. Even though it is not desired to be united by the following theory, it is believed that during the process of reactive extrusion of the polyethylene oxide resins, and initiator begins three competitive reactions: 1) the graft and vinyl monomer on the polyethylene oxide , 2) degradation of the polyethylene oxide and 3) cross-linking of the polyethylene oxide. A novel method to achieve improved properties has been developed that is contrary to traditional thinking methodology in polymer development. The method degrades the polymer into shorter chains as opposed to only increasing the molecular weight by grafting and cross-linking. The resulting modified polyethylene oxide compositions have improved the melt strength and melt elasticity, overcoming the inherent de? Ciencies of both the low molecular weight polyethylene oxide and the higher molecular weight polyethylene oxide.

In the case of grafting, the presence of a sufficient amount of monomers as demonstrated in the examples given herein, in the crosslinking is negligible and does not adversely affect the properties of the modified polyethylene oxide. The cross-linking reaction only predominates when there is very little or no monomer present during the modification of the polyethylene oxide resin. Therefore, grafting and degradation reactions of polyethylene oxide must predominate and are desired to produce the polyethylene oxide compositions suitable for fiber and film manufacturing purposes.

The modified polyethylene oxide resins are observed as having improved melt strengths melt elasticities overcoming the inherent deficiencies of both low molecular weight and higher molecular weight polyethylene oxides. These improved melt properties allow the modified polyethylene oxide to be processed into useful fibers with diameters of less than 100 microns using conventional fiber pulling techniques. These same improved melt properties also allow the modified polyethylene oxide resin to be processed and useful films with thicknesses of less than 0.5 mils d inch and with improved balanced solid state properties.

The present invention has been illustrated in detail by the above specific examples. It is understood that these examples are illustrative embodiments and that this invention should not be limited by any of the example details of the description. Those skilled in the art will recognize that the present invention is capable of many modifications and variations without departing from the scope of the invention. Therefore, a detailed description and examples are intended to be illustrative and not to limit in any way the scope of the invention as set forth in the following claims. Rather, the annex clauses should be considered broadly within the scope and spirit of the invention.

Claims (20)

R E I V I N D I C A C I O N S

1. A poly (ethylene oxide) composition has a polydispersity index of less than 10.

2. The poly (ethylene oxide) t composition and as claimed in clause 1, characterized in that poly (ethylene oxide) has a melt temperature of 68 ° C.

3. The poly (ethylene oxide) t composition and as claimed in clause 2, characterized in that poly (ethylene oxide) has an average molecular weight of pe of more than about 60,000 g / mol.

4. The poly (ethylene oxide) t composition and as claimed in clause 3, characterized in that poly (ethylene oxide) has an average molecular weight of pe of more than about 90,000 g / mol.

5. The poly (ethylene oxide) ta composition and as claimed in clause 1, characterized in that poly (ethylene oxide) has a polydispersity index d less than about 6.

6. A modified poly (ethylene oxide) comprising a poly (ethylene oxide) column with polar species grafted to the poly (ethylene oxide) column.

7. The modified poly (ethylene oxide) as claimed in clause 6, characterized in that the polar species is selected from the group consisting of poly (ethylene glycol) methacrylates and 2-hydroxyethyl methacrylate.

8. The modified poly (ethylene oxide) as claimed in clause 7, characterized in that the polar species is poly (ethylene glycol) methacrylate.

9. The modified poly (ethylene oxide) copolymer as claimed in clause 8 characterized in that the poly (ethylene glycol) methacrylate is poly (ethylene glycol) ethyl ether methacrylate.

10. Modified poly (ethylene oxide) as claimed in clause 9, characterized in that poly (ethylene glycol) ethyl ether methacrylate has a number average molecular weight of no more than about 5,000 grams per mole.

11. The modified poly (ethylene oxide) as claimed in clause 7, characterized in that the polar species is 2-hydroxyethyl methacrylate.

12. The modified poly (ethylene oxide) as claimed in clause 6, characterized in that modified poly (ethylene oxide) has a polydispersity index of less than 10.

13. The modified poly (ethylene oxide) as claimed in clause 6, characterized in that modified poly (ethylene oxide) has a molten temperature of less than 68 ° C.

14. Modified poly (ethylene oxide) as claimed in clause 6, characterized in that modified poly (ethylene oxide) comprises from about 0.1 to about 20 weight percent of polar species relative to the weight of the poly column (ethylene oxide) .

15. The modified poly (ethylene oxide) as claimed in clause 14, characterized in that modified poly (ethylene oxide) comprises from about 0.5 to about 10 weight percent of polar species relative to the weight of the poly column (ethylene oxide) .

16. A grafted poly (ethylene oxide) having a polydispersity index of less than 10.

17. The grafted poly (ethylene oxide) and co is claimed in clause 16, characterized in that grafted poly (ethylene oxide) has a melt temperature of less than 68 ° C.

18. The grafted poly (ethylene oxide) and co is claimed in clause 17, characterized in that grafted poly (ethylene oxide) has a weight average molecular weight of more than about 60,000 g / mol.

19. The grafted poly (ethylene oxide) and co is claimed in clause 18, characterized in that grafted poly (ethylene oxide) has an apparent viscosity less than 200 Pascal * seconds at cut-off rates of not less than 10 seconds "1 and of no more than 1,000 seconds "1.

20. The grafted poly (ethylene oxide) is as claimed in clause 16, characterized in that the grafted poly (ethylene oxide) has a polydispersity index d of less than about 6. E S U M E N Modified poly (ethylene oxide) compositions are described. The polyethylene oxide compositions have improved melt processability and properties and can be used to thermally process articles which have improved properties on similarly processed articles of unmodified polyethylene oxide compositions.