KR20030096324A - Processing of Polyhydroxyalkanoates Using a Nucleant and a Plasticizer - Google Patents

Abstract

The present invention relates to polyhydroxyalkanoate copolymer compositions that can be easily and quickly processed into extruded and shaped articles. More specifically, the present invention relates to the melt processing of polyalkanoates containing novel combinations of nucleant and plasticizers to increase the crystallization rate and thus improve processability.

Description

Processing of Polyhydroxyalkanoates Using a Nucleant and a Plasticizer

Polyhydroxyalkanoate (PHA) and other thermoplastic polyesters represent potential raw materials for many useful products. Examples include melt spun fibers, from which nonwovens for medical gowns and masks, blown and cast films for mixed foodstuffs and garbage bags, injection molded bottles for health and personal care products, and biodegradable / compostable Extrusion coatings on paper / paper boards for fast food containers can be made. In the process of making PHA products, it is important to achieve economically desirable line speeds, cycle times and other processing parameters.

Polyhydroxyalkanoate copolymers are very adherent when melt processed, at least in part, due to the extremely slow crystallization rate of the crystalline region. This sticky or "tacky" behavior prevents the polymer from being processed through any melt processing equipment, including extrusion, blending, film and fiber workpieces. Unmodified polymers have a strong tendency to adhere to all parts of the machine, regardless of the constituent material. The polymer also has a strong tendency to attach to itself and to attach to human skin upon contact. Adhesion or adhesion gradually disappears within minutes to hours. However, for any conventional processing technique, this time range is significantly long, and generally the polymer needs to be non-tacky within a few seconds.

Previous studies have shown that some compositions of polyhydroxyalkanoate copolymers can be added to crystallization nucleating agents to increase the crystallization rate to a point where melt processing capacity is acceptable. In addition, such nucleating agents can sometimes improve the physical and mechanical properties of processed articles. Examples of conventional nucleating agents include talc, pulverized mica, calcium carbonate, boron nitride (see eg European Patent No. 0291024) and ammonium chloride (see eg WO 9119759).

US Pat. No. 5,296,521 discloses thermoplastic polyester resins and 0.5-5% by weight of the formula RO [P (O) (Ph) (CH ₂ ) _m O] _n H, wherein R is an alkali or alkaline earth metal; m is 1, 2 or 3; n is an average value in the range of 1 to 5). The nucleating agent may optionally be mixed with the acid or ester form so that at least 50 mol% of the nucleating agent is in the form of a salt. This nucleating agent is preferably in the form of a sodium salt (eg, a sodium salt of hydroxymethylphenyl phosphonic acid or a sodium salt of oligomethylene phenyl phosphinic acid).

U.S. Patent No. 4,536,531 describes carboxylates of Group I and Group II metals on the periodic table as nucleating agents for polyesters, for example acetic acid, propionic acid, caproic acid, palmitic acid, stearic acid, oleic acid, behenic acid and mon The use of metal salts of aliphatic monocarboxylic acids such as carbonic acid is described. Suitable metals are sodium, potassium, lithium, magnesium, calcium, barium and zinc. In these carboxylate salts, not all of the carboxyl groups need to be converted to the salt form, but some of the carboxyl groups may be in salt form and the remaining groups may be in free acid or ester form.

Some documents disclose the use of organic phosphorus compounds as nucleating agents. U.S. Patent 5,061,743 discloses preferred polyhydroxyalkanoate nucleating agents prepared by dry blending cyclohexylphosphonic acid and zinc stearate with polyhydroxybutyrate-co-valerate. This nucleating agent has been described as being particularly advantageous for the nucleation of polyhydroxybutyrate-co-valerate with a high content of hydroxyvalerate. WO 9905208 discloses that organic phosphorus compounds having two or more phosphonic acid residues can be used as nucleating agents for polyhydroxyalkanoates and other thermoplastic polyesters.

Many of these compounds have been found to be effective in increasing the nucleation density of polyhydroxyalkanoates and thus in the rate of crystallization, but certain disadvantages have been associated with their use. For example, dispersion of particulate nucleating agents has been a problem because agglomeration occurs frequently during processing, which can result in stress concentrations and non-uniform regions in the moldings. In addition, nucleating agents such as boron nitride have been shown to act as pigments in some cases, especially in films and injection moldings, resulting in the formation of opaque products in general when transparent products are required. In addition, some nucleation systems contain components that may be environmentally and toxicologically undesirable.

In addition, the polymers in this document tend to be copolymers that do not contain comonomers that effectively increase the amorphousness or reduce the crystallization rate of the polymer. The resulting polymers are often fragile and have undesirable properties. Polyhydroxyalkanoate copolymers containing more modified comonomers to form significant amounts of amorphous form tend to be more preferred polymers because they exhibit a high degree of toughness and elasticity resilience. However, the large amounts of amorphous forms contained in these polymers do not lead to good crystal formation or fast crystallization rates. In addition, the addition of nucleating agents to these polymers generally does not increase the amount or crystallization rate of crystallization sufficiently to produce melt processed products of these polymers. Therefore, a good and cost effective nucleating agent system is required for producing a polyhydroxyalkanoate resin with moderately high crystallinity and excellent moldability, mechanical strength and dimensional stability.

Accordingly, the problem to be solved is to provide a polymer composition that forms tough, flexible polyhydroxyalkanoate that can be easily and quickly processed into a film based product. Another object of the present invention is to provide a continuous melt extrusion method of these polyhydroxyalkanoates. Another object of the present invention is to provide a method for producing a continuous cast film using these polyhydroxyalkanoates.

Summary of the Invention

The present invention, (a) polyhydroxyalkanoate copolymer; (b) nucleating agents; And (c) a polyhydroxyalkanoate copolymer composition that can be processed into a film based product, an extruded article and a molded article, and a coating, comprising a plasticizer, and a method for producing the same.

In one preferred embodiment, a unique combination of poly-3-hydroxy (butyrate-co-octanoate) or poly-3-hydroxy (butyrate-co-hexanoate) is prepared with polyhydroxybutyrate (nucleating agent) and methyl. Polymerize with laurate or dibutylmaleate (plasticizer).

The present invention relates to the field of polyhydroxyalkanoate polymers, articles made therefrom and melt processing methods. More specifically, the present invention relates to melt processing of polyhydroxyalkanoates containing a novel blend of nucleant and plasticizer to increase the chain mobility, crystallization rate and improve the processability compared to conventional melt processing. And cast film extrusion.

Applicants have solved this problem by providing a combination of nucleating and plasticizers in polyhydroxyalkanoate ("PHA") copolymers. By adding a nucleating agent and a plasticizer to the PHA copolymer, crystallization processing occurs within a time range where substantial melt processing is possible. The present invention is applicable in any case where acceleration of the crystallization rate is required. In particular, nucleating agents and plasticizers are used to improve the productivity of PHAs and other thermoplastic polyester products by reducing the number of cycles normally required for the production of films, extruded and molded articles and coatings.

Many terms and abbreviations are used in the present invention. These are defined as follows.

“Poly (3-hydroxybutyrate-co-3-hydroxyoctanoate), also known as“ poly-3-hydroxy (butyrate-co-octanoate) ”, is abbreviated as P3HBO.

"Poly-3-hydroxy (butyrate-co-hexanoate)", also known as "poly-3-hydroxy (butyrate-co-hexanoate)" is abbreviated as P3HBH.

"Polyhydroxyalkanoate" is abbreviated as PHA.

"Polyhydroxybutyrate" is abbreviated as PHB.

Polyhydroxyalkanoate

Polyhydroxyalkanoates ("PHAs") of the present invention include polyhydroxybutyrates (PHBs) including natural polymers such as homopolymers of 3-hydroxybutyrate and 4-hydroxybutyrate. They can also be copolymers of PHB with hydroxy acids, for example PHB with 3-hydroxyhexanoate, 3-hydroxyoctanoate, or long chain hydroxy acids (eg C ₉ to C ₁₂ hydroxy acids ) And copolymers thereof. The PHAs of the invention can also be derived synthetically from hydroxy carboxylic acids. In addition, PHAs can be present primarily in R (-) arrangements, mainly in S (+) arrangements, or in combinations of random, block or other R (-) and S (+) arrangements. As will be appreciated by those skilled in the art, the R (-) and S (+) isomers mean that the repeat units of the polymer can rotate the plane of polarization counterclockwise or clockwise, respectively. Racemic copolymers consist of both R (-) and S (+) repeat units in polymers that can be arranged in any combination, including random or block arrangements.

Preferred examples of the polyhydroxyalkanoate copolymers used in the present invention include poly-3-hydroxy (butyrate-co-octanoate) (y = 3) (P3HBO) and poly-3-hydroxy Hydroxy (butyrate-co-hexanoate) (y = 1) (P3HBH). These block copolymers have a generalized structure where m is 0.7 to 0.97, n is 0.3 to 0.03, and m + n is 1.0.

Wherein R is CH ₃ (CH ₂ ) _y , where y is 0-11.

In general, block copolymers can be prepared in a variety of configurations. For example, in the AB diblock copolymer, the blocks of the polymer A segment are coupled with the blocks of the B polymer segment. In ABA triblock copolymers, blocks of the B segment are coupled with blocks of the A segment at their respective ends. The-(AB) _n -multiblock copolymer has alternating A and B segments where n is a positive integer greater than one. Especially preferred are random block copolymers wherein the PHB segment comprises from 85 to about 95 weight percent of the copolymer. PHAs for use in the present invention have a weight average molecular weight of about 600,000 to more than 1,000,000, and a number average molecular weight of about 280,000 to 500,000 g / mol.

Generally, conventional melt processing makes it difficult to process PHA into films, fibers, filaments, rods, tubes, or other forms having physical integrity. Conventional melt processing methods include continuous melt extrusion processing, cast film extrusion, blown film extrusion, melt spinning processing, and other methods generally known to those skilled in the art. By "polymer difficult to melt" is meant a polymer that exhibits an effective melt strength and / or curing time that would impair the ability to form a product with physical integrity by conventional melt extrusion processing.

"Effective melt strength" means resistance to the molding polymer being drawn to the desired dimensions, for example thickness (for films), or diameter or denier (for fibers or filaments). Polymers with low effective melt strength cannot withstand the minimum strain required to draw the polymer melt to the desired dimensions. For example, the polymeric material may exhibit instability, such as bursting, sagging or draw resonance. The resulting product tends to be very heterogeneous in physical integrity.

"Cure time" means the time required for a shaped polymeric material to achieve a substantially non-tacky or non-stick physical state, under established processing conditions. Curing time is important because blocking may occur if the polymer does not cure in a suitable time during processing. Thus, polymeric materials with residual tack can adhere to themselves and / or to processing equipment even after cooling to below room temperature. This residual tack can limit the rate at which the product can be processed or prevent the product from being collected in a form of suitable quality.

Curing time is affected by polymeric materials and processing equipment and conditions. In general, the curing time should be in seconds under conventional processing conditions. Such conditions typically include a range of temperatures of the chill roll as known in the art to a melting temperature of the material to be processed, which may be about 150 ° C. or less (preferably 120 to 135 ° C.). In general, the longer the number of processing cycles (eg from the melt extrusion point to the harvest point of collection), the longer the number of curing cycles tends to be tolerated.

The term "adhesiveness" or "adhesiveness" is known to those skilled in the art to mean an amount of adhesion or adhesion. Tackiness is generally a subjective measure measured by contact of a finger with a film surface. If the surface is "adhesive", or if it is adherent, it has the property of "adhesive". Adhesion can be measured subjectively on many scales, but to illustrate this concept, flypaper is a Teflon® sheet (polytetrafluoroethylene) (Wilmington, Delaware, USA). A lack of adhesion to the iDu Pont de Nemours and Company may be considered a high point scale. For the purposes of the present invention, a single operator subjectively measures the adhesion after pressing a film of a suitable polymer blend five times between two Teflon® coated aluminum foil sheets. After the fifth compression, the sample film is cooled at room temperature for 10 seconds and the relative force required to first remove this film from the Teflon® sheet is measured. In addition to the force required to peel off the polymer from the worker's glove, the force required to fold the film over itself and then peel off from itself is subjectively monitored. The results are reported as “no stickiness” unless clearly additional force is required to remove the film from the Teflon® sheet or from itself after folding. Subjectively graded “slightly tacky” to “moderately tacky” means that greater force is required in each category to remove the film from the Teflon® sheet and itself. The category of "adhesiveness" generally means that it is extremely difficult to remove the film from the Teflon® sheet when cooled under a standard time of 10 seconds, and it is virtually impossible to separate it from itself after folding the film.

Nuclear agent

A "nucleating agent" or "nucleating agent" is a compound used to artificially introduce nucleation sites for crystallization processing from the molten state of polyhydroxyalkanoate. The detailed description is given under line 36, first paragraph of US Pat. No. 5,534,616. This reference is incorporated herein by reference. Nucleating agents help compensate for the slow crystallization rate of many PHAs due to the low nucleation density. The preferred amount of nucleating agent in the composition is from about 1% to about 10% based on the fill weight of the composition. The nucleating agent in the preferred composition is polyhydroxybutyrate and ranges from about 0.005% to about 20%, more preferably from about 0.05% to about 10%, most preferably from about 0.5% to about 5%, based on the total weight of the composition It is used in the amount of.

Plasticizer

Plasticizers are used in the compositions of the present invention to modify the mechanical properties of molded articles and to improve the processability of the compositions. In general, plasticizers reduce the modulus and tensile strength of polymer products and tend to increase ultimate elongation, impact strength and tear strength. Plasticizers can also be used to enable melt processing at lower temperatures by lowering the melting point of the composition. In the present invention, plasticizers are used as adjuvants to reduce the glass transition temperature to increase the rate at which non-tacky products will be obtained.

External plasticizers known in the art include glycerol, ethylene glycol, and low molecular weight polyethylene glycols. Preferred plasticizers for the PHA tested are di (2-ethylhexyl) (dioctyl) maleate, paraffin, dodecanol, olive oil, soybean oil, polytetramethylene glycol, methyl oleate, n-propyl oleate, tetrahydrofur Furyl oleate, epoxidized linseed oil, 2-ethylhexyl epoxytalate, glycerol triacetate, methyl linoleate, dibutyl fumarate, methyl acetyl ricinoleate, acetyl tri (n-butyl) citrate, acetyl triethyl Citrate, tri (n-butyl) citrate, triethyl citrate, bis (2-hydroxyethyl) dimerate, butyl ricinoleate, glyceryl tri- (acetyl ricinoleate), methyl ricinoleate, n -Butyl acetyl ricinoleate, propylene glycol ricinoleate, diethyl succinate, diisobutyl adipate, dimethyl azelate, di (n-hexyl) azelate and Tri-butyl phosphate. Most preferred plasticizers for the PHA tested include methyl laurate and di-n-butyl maleate. Preferred amounts of plasticizer in the composition are from about 5% to about 35%, more preferably from about 12% to about 20%, based on the total weight of the composition.

Melt extrusion method

Conventional melt extrusion methods are used to produce the extruded and molded articles of the present invention. Such melt extrusion methods include blending of polymer components followed by blend extrusion. In a preferred embodiment, the strand of PHA polymer is extruded through a die plate into a water bath at a temperature of about 30 to 40 ° C. at about 120 to 160 ° C., more preferably at 130 to 145 ° C.

In a preferred melt extrusion method of the present invention, pellets of polymer components are first produced. The PHA nucleating agent and the plasticizer may be first dry blended and then melt mixed in the film extruder itself. In addition, if insufficient mixing occurs in the melt extruder, the components may first be dry blended and then mixed in a preblend extruder and then pelletized before melt extrusion.

The PHA films of the present invention can be processed using conventional methods and used for producing single or multilayer films on conventional film making equipment. The cast or blown film extrusion process used to make the PHA films of the present invention is more fully described in US Pat. No. 6,027,787, which is incorporated herein by reference, and is described in Plastics Extrusion Technology-2 ^nd Ed., Allan A. Griff. (Van Nostrand Reinhold, 1976). In one preferred embodiment, the PHA polymer continuous film is extruded on a roller at a temperature of about 30 to 45 ° C., more preferably about 40 ° C. at about 120 to 160 ° C., more preferably 120 to 140 ° C.

By "film" is meant a continuous piece of extruded material having a high ratio of length to thickness and a high ratio of width to thickness. Although no exact upper or lower limit is required, preferred film thicknesses of the present invention are about 0.05 to about 50 mils, and more preferred film thicknesses are about 0.5 to about 15 mils. The film of the present invention may comprise one or more layers.

It is also possible to prepare the PHA compositions of the invention into certain selected molded articles by conventional injection molding techniques.

The invention is further illustrated in the following examples. It is to be understood that these examples represent preferred embodiments of the present invention and are provided only as examples. From the above description and the following examples, those skilled in the art can identify the essential characteristics of the present invention, and various changes and modifications of the present invention can be applied to various uses and conditions without departing from the spirit and scope of the present invention. have.

The abbreviations are as follows: "mL" means milliliters, "L" means liters, "ft" means feet, "lb" means pounds, and "g" means grams.

General method

Poly-3-hydroxy (butyrate-co-octanoate) (P3HBO) was purchased from Procter and Gamble Company, Inc., Cincinnati, Ohio. Poly-3-hydroxy (butyrate-) from Procter and Gamble Company, Inc (Cincinnati, Ohio), the Biotechnology Development's Jiangmen Center and Tsinghua University (China) Co-hexanoate) (P3HBH) was purchased. PHB was purchased from Aldrich Chemical Company, Inc., St. Louis, Missouri.

<Example 1>

Identifying Combinations of "Active" Nucleants and Plasticizers

The combination of nucleating agent and plasticizer was screened as follows: First, an appropriate amount of nucleating agent PHB and a powder of P3HBO or P3HBH were tumble blended to produce a melt blend of PHB and PHA, specifically P3HBO or P3HBH. Generally, 1 wt% (0.75 g) of PHB was added to the P3HBO (74.25 g) polymer and 3 wt% (2.25 g) of PHB was added to the P3HBH (72.75 g) polymer. (Nutrient addition ratios were determined by anti-adhesion performance in preliminary experiments.) After tumble blending of the appropriate components, power was supplied to a small 16 mm Prism (PRISM) twin screw extruder with a maximum temperature set to 155 ° C. The polymer was melt extruded into a water bath through a single hole 3/16 inch die on a water cooled “nonstick” belt. The polymer tended to adhere to the belt and the polymer was cut to 2-3 feet long and spread over the rack to allow crystallization to occur over time. After 20 minutes to 1 hour, the polymer strands were sufficiently crystallized and could be cut manually (with scissors) or through a blade cutting machine to produce small (2-8 mm long) pellets. This pellet was then pressed into a film under the following conditions: compression temperature (140 ° C.); Pressure (1000 psi); Compression time (2 minutes); And cooling temperature (25 ° C.). The resulting film was then cut into strips 2-5 mm wide and used for the screening process.

Since good mixing equipment was not available for blending very small amounts of polymers and plasticizers, the following method was developed and the melt blends of polymers, nucleating agents and plasticizers were screened accordingly. 0.4 g of the desired plasticizer was added to a small test tube. The test tube containing the plasticizer was placed in a metal bath of Wood heated to 160 ° C. and held there for 10 minutes. After preheating the plasticizer, 1.6 g of a suitable PHA film strip containing PHB nucleating agent (prepared as described above) was added to the test tube. Thereafter, the entire contents of the test tube were further heated at 160 ° C. for 50 minutes. Thereafter, the test tube was removed from the heating bath and cooled at room temperature for at least 1 hour. The resulting polymer blend was removed from the test tube (this test tube was ruptured if necessary). The resulting polymer and any liquid contents are placed on a Teflon® coated aluminum foil sheet (commercially available from E.I.Dupont Nemoas and Company, Wilmington, Delaware, USA) and onto a film. Squeezed. The film was then removed from the sheet, folded over itself and pressed back into the film. The film compression process was repeated five times to ensure good blending of the three components and to evaluate the effectiveness of the nucleating agent plasticizer formulation. Generally the film processing conditions were as follows: compression temperature (140 ° C.); Compression pressure (1000 psi); Compression time (2 minutes); Cooling temperature (room temperature); And cooling time (10 seconds). Immediately after the final film was pressed and cooled for 10 seconds, the sample was peeled off from the Teflon® coated sheet and the adhesion to the Teflon® coated sheet, the film itself, and the worker glove was evaluated. If the adhesion or adhesion as defined is not shown for any surface to which it is exposed, it is rated as "no adhesion". All other grades indicate some degree of stickiness. Thereafter, any residual plasticizer was washed away from the sample and weighed. The incorporation rate of the plasticizer was determined by comparing the final polymer weight with the theoretical weight and recalculating the plasticizer content assuming only plasticizer loss. The sample calculation method is as follows:

Ingredients Added:

1.6 g (nucleating agent + polymer) into film

0.4 g of plasticizer

Total processed ingredients = 1.60 g + 0.40 g = 2.00 g

Theoretical amount of plasticizer (%) = (0.40 g / 2.00 g) × 100% = 20%

Common example:

Actual final weight of film = X g

Assumed plasticizer final weight = X g-1.60 g = Y g

Actual amount of plasticizer (%) = (Y g / X g) × 100%

Specific example:

Actual final weight of film = 1.86 g

Assumed plasticizer final weight = 1.86 g-1.60 g = 0.26 g

Actual amount of plasticizer (%) = (0.26 g / 1.86 g) x 100% = 14%

In no case should it be noted that less than 1.60 g of film was produced, indicating that in all cases some plasticizer was incorporated into the polymer.

Tables 1a to 1c (Examples 1 to 44) below summarize the results of screening nucleating agents and plasticizers containing both P3HBO and P3HBH, respectively, and showing no tackiness. Tables 2a and 2b (Examples 45 to 60) below summarize the comparative examples showing tackiness. The abbreviations Tg used in Tables 1a to 1c and Tables 2a and 2b below represent the glass transition temperature (° C.).

In general, for samples graded "no tack", samples containing more plasticizer tended to be better than samples containing less plasticizer (which showed much less stickiness). Sometimes, some films were still tacky when cooled at room temperature. When these same films were cooled at 65 ° C., some of them did not exhibit tackiness. These films were graded as non-tacky but considered inferior to non-tacky after cooling for 10 seconds at room temperature. Samples showing rapid tack removal were considered candidates for melt processing through injection molding, film extrusion and fiber extrusion.

<Example 2>

Description of continuous melt extrusion and online pelletization of poly-3-hydroxy (butyrate-co-hexanoate) into strands

Blending of Ingredients (Di-n-butylmaleate Plasticizer): In 35 gallons of fiberpack, 15088.6 g of powdered P3HBH and 588.5 g of powdered PHB were added. 3923.0 g of di-n-butylmaleate was slowly added to this powder mixture at a rate at which the liquid plasticizer was immediately absorbed into the powder. The fiberpack was then placed on a barrel tumbler and tumbled for 6 hours to ensure good mixing.

Extrusion and Pelletization of Polymer Strands (Di-n-butylmaleate Plasticizer): After the polymer components were tumbled as above, the resulting mixture was fed into a 30 mm twin screw extruder at a rate of approximately 10 lbs / hour. The extrusion temperature was set to maintain a barrel temperature gradient of 120 ° C. to 160 ° C. The screw RPM was kept at 100. The resulting molten polymer was extruded through a 3/16 inch die into a 12 foot long water trough maintained at a temperature of 34 ° C. to 38 ° C. The polymer was cut at a rate of 6-8 ft / min and fed directly into a Conair polymer cutter. A total of 40.9 lb pellets were harvested.

The resulting polymer strands showed some stickiness within the top six feet of the quench trough. After the strands became non-tacky in the water trough, the polymer became non-tacky during the processing operation or at any time during subsequent processing operations.

<Example 3>

Description of continuous melt extrusion and online pelletization of poly-3-hydroxy (butyrate-co-hexanoate) into strands

Blending and Extrusion of Polymer Strands, and Pelletization (Methyl Laureate Plasticizer): The following components were blended in a similar manner as described for the polymer blended with di-n-butylmaleate in Example 2: P3HBH 11,793 g , 459.5 g PHB and 3063 g methyl laurate. The resulting mixture was then fed into a 30 mm extruder set to maintain a barrel temperature gradient of 120 ° C. to 160 ° C. as described above. The screw RPM was maintained at 100 and the polymer was extruded through a 3/16 inch die into a 12 foot long water trough maintained at 34 ° C. to 38 ° C. The polymer was snore and cut at a rate of approximately 12 ft / min with a polymer cutter. The polymer quench time (time when no more adhesion was observed) was approximately 25 seconds. A total of approximately 32 lbs of nonstick pellets were harvested. Methyl laureate accelerated the quenching time faster and therefore the cutting rate faster.

<Example 4>

Description of continuous cast film preparation using poly-3-hydroxy (butyrate-co-hexanoate) and methyl laurate plasticizer

P3HBH pellets plasticized with methyl laureate and nucleated with PHB prepared in the previous example were fed into a single screw extruder equipped with a 14 inch film die and set to maintain a barrel / die temperature gradient of 140 ° C to 120 ° C. The resulting polymer extrudate was cast on a 12 inch diameter stainless steel roll set at a temperature of 40 ° C. The extruded film was collected on a quench roll and then on a packaging roll in a speed range of 2 ft / min to 13 ft / min to produce a film having a thickness in the range of 1 mil to 10 mil. The film was non-tacky and measured according to the properties summarized in Table 3 (ASTM D 882-95a-Standard Test Method for Tensile Properties of Thin Plastic Sheeting). ).

Claims (25)

A reduced tackiness polyhydroxyalkanoate polymer composition comprising (a) a polyhydroxyalkanoate copolymer, (b) a nucleant, and (c) a plasticizer. A reduced tack polyhydroxyalkanoate polymer composition comprising (a) 55-94% polyhydroxyalkanoate copolymer, (b) 1-10% nucleating agent, and (c) 5-35% plasticizer . The polyhydroxyalkanoate polymer composition of claim 1, wherein the polyhydroxyalkanoate copolymer is selected from compounds of formula (I) <Formula I> In the formula, R is CH ₃ (CH ₂ ) _y , wherein y is 0 to 11, m is 0.7 to 0.97, n is 0.3 to 0.03, and m + n is 1.0. The polyhydroxyalkanoate copolymer according to claim 1, wherein the polyhydroxyalkanoate copolymer is selected from the group consisting of poly-3-hydroxy (butyrate-co-octanoate) and poly-3-hydroxy (butyrate-co-hexanoate). The selected polyhydroxyalkanoate polymer composition. 2. The polyhydroxyalkanoate polymer composition of claim 1, wherein said nucleating agent is polyhydroxybutyrate. The polyhydroxyal compound of claim 1, wherein the nucleating agent is selected from the group consisting of talc, pulverized mica, calcium carbonate, boron nitride, ammonium chloride, sodium salt and carboxyl salts of group I and group II metals on the periodic table. Decanoate polymer composition. The method of claim 1, wherein the plasticizer is di-n-butyl maleate, methyl laurate, dibutyl fumarate, di (2-ethylhexyl) (dioctyl) maleate, paraffin, dodecanol, olive oil, soybean oil, Polytetramethylene glycol, methyl oleate, n-propyl oleate, tetrahydrofurfuryl oleate, epoxidized linseed oil, 2-ethylhexyl epoxytalate, glycerol triacetate, methyl linoleate, dibutyl fumarate, methyl Acetyl ricinoleate, acetyl tri (n-butyl) citrate, acetyl triethyl citrate, tri (n-butyl) citrate, triethyl citrate, bis (2-hydroxyethyl) dimerate, butyl ricinoleate , Glyceryl tri- (acetyl ricinoleate), methyl ricinoleate, n-butyl acetyl ricinoleate, propylene glycol ricinoleate, diethyl succinate, diisobutyl acetonitrile A polyhydroxyalkanoate polymer composition selected from the group consisting of diate, dimethyl azelate, di (n-hexyl) azelate and tri-butyl phosphate. Contacting the polyhydroxyalkanoate polymer with a nucleating agent and a plasticizer to form the polyhydroxyalkanoate polymer composition, thereby improving the processability of the polyhydroxyalkanoate polymer composition by reducing the tackiness. The method of claim 8, further comprising extruding the polyhydroxyalkanoate polymer composition. The method of claim 9, further comprising pelletizing the extruded polyhydroxyalkanoate polymer composition. The method of claim 10 further comprising extruding the pelletized polyhydroxyalkanoate polymer composition. The method of claim 10 wherein the polyhydroxyalkanoate polymer composition is extruded through a compounding extruder. An extruded article comprising the polyhydroxyalkanoate polymer composition of claim 1. The extruded article according to claim 13 in the form of fibers, filaments, rods, tubes or cast films. The cast film of claim 14 wherein the film thickness is from about 0.05 to about 50 mils. The cast film of claim 14 wherein the film thickness is from about 0.10 to about 15 mils. An extruded article produced by the method of claim 8. An extruded product produced by the method of claim 9. An extruded product produced by the method of claim 11. An extruded article produced by the method of claim 12. An extruded article produced by the method of claim 8 in the form of a fiber, filament, rod, tube or cast film. An extruded article produced by the method of claim 9 in the form of a fiber, filament, rod, tube or cast film. An extruded article produced by the method of claim 11 in the form of a fiber, filament, rod, tube or cast film. An extruded article produced by the method of claim 12 in the form of a fiber, filament, rod, tube or cast film. An injection molded article comprising the polyhydroxyalkanoate polymer composition of claim 1.