US 20090234042A1 (19) United States (12) Patent Application Publication (10) Pub. No.: US 2009/0234042 A1 Luinstra (43) Pub. Date: Sep. 17, 2009

(54) TRANSPARENT BLENDS OF (86). PCT No.: PCT/EP07/53759 POLY PROPYLENE CARBONATE S371 (c)(1), (2), (4) Date: Oct. 23, 2008 (75) Inventor: Gerrit Luinstra, Mannheim (DE) (30) Foreign Application Priority Data

Correspondence Address: Apr.p 27,s 2006 (EP) ...... O61132O15 CONNOLLY BOVE LODGE & HUTZ, LLP Mar. 27, 2007 (EP) ...... O7104484.6 PO BOX 2207 Publication Classification WILMINGTON, DE 19899 (US) (51) Int. Cl. COSL 69/00 (2006.01) (73) Assignee: BASF SE, Ludwigshafen (JP) (52) U.S. Cl...... 523/105:524/502 (57) ABSTRACT (21) Appl. No.: 12/298,251 This invention is directed to transparent blends of polypropy lene carbonate with poly lactide and/or polyhydroxyal kanoates, to a process for the preparation of said blends as (22) PCT Filed: Apr. 18, 2007 well as the use of said blends. US 2009/0234042 A1 Sep. 17, 2009

TRANSPARENT BLENDS OF goods (e.g. Vegetables, fruits, meat) or to uniformly dying at POLY PROPYLENE CARBONATE low effort and costs. We thus set out to find blend components for polypropylene carbonate to improve the glass temperature and/or young modulus and to keep the excellent transparency 0001. This invention is directed to transparent blends of in the resulting materials. polypropylene carbonate with polylactide and/or polyhy 0007 Surprisingly, it is found that a transparent polypro droxyalkanoates, to a process for the preparation of said pylene carbonate (PPC) blend is formed by blending it with blends as well as the use of said blends. PLA (polylactid acid) independently of the ratio of the two 0002 High molecular weight Polypropylencarbonate components (PLA and PPC) in the blend. (PPC) is a thermoplastic, amorphous (transparent) material 0008. Yet in another embodiment of this invention, trans with a glass temperature in the range of 25 to 45° C. Latter is parent blends of polypropylene carbonate and PHB(V) are depending on the carbonate linkage percentage and the pres prepared, wherein the maximum amount of PHB(V) is not ence and amount of plasticizers like cyclic propylene carbon exceeding 15 parts by weight of a total of 100 in the sum with ate, which is a typical thermal decomposition product and/or polypropylene carbonate. This is very Surprising and favor side product of the synthesis. This means that the softening able for the properties of the blend. point of the polypropylene carbonate is usually at room or 0009. In addition, the blends according to the invention body temperature. This is disadvantageous for some applica have a higher glass temperature than the starting material tions in for example packaging sector: container prepared PPC. Furthermore, we found that the elastic modulus of said from polypropylene carbonate through injection or blow blends could be improved without losing the transparency. moulding will loose their shape inside a closed car on a Sunny The resulting blends can be processed using standard meth day in the Sun. In addition, granulate of polypropylene car ods including injection and blow moulding and are Suitable bonate tend to clog together at ambient temperature. As a for applications in packaging, play (toys, recreational), consequence, the transport in form of the usual pellets from hygiene (household) and medical, construction, sporting and manufacturer to customers may resultina Sticky block, which art SectOr. cannot be handled by standard equipment. As a result addi tional costs arise, for example for necessary milling or melt Details ing equipment. 0003. The above situation is unfavourable for the applica (0010. The transparent blends of PPC comprise the follow tion of polypropylene carbonate as a thermoplastic material. ing components wherein the sum of the parts of PPC and PLA An increase in the glass temperature and young modulus of or PHB are 100 parts by weight the thermoplastic material would improve the properties with a) a first embodiment: respect to application purposes and processing. The glass 0011 (i) 1-99 parts by weight of polypropylencarbonate temperature of a polymeric material can for example be having a molecular weight (Mn) between 30,000 and increased through the formation of blends with other materi 5,000,000 Da, als including with other polymers. 0012 (ii) 99-1 parts by weight of polylactid, 0004 Blends of polypropylene carbonate are known, 0013 (iii) 0.1-25 parts of an additional component that is however, they are all non-transparent as the result of a non known to function as an antioxidant, a flame retardant, a compatibility. This is expected, since different polymers tend filler, a (metal) complexing agent, a plasticizer or process to be immiscible. This has been explained by for example the ing aid, pigment, dye, brightener and/or antistatic agent; differences in solubility parameter Van Krevelen, Chapter 0014. The first embodiment comprises preferably: 7.: from a theoretical point of view, the solubility parameter 00.15 (i) 10-90 parts by weight of polypropylencarbonate of two components have to be identical within 0.1 (J/cm)'. having a molecular weight (Mn) between 30,000 and This is rarely the case, and it is thus to be expected that 50,000 Da, polymers in general are immiscible as is observed for the 0016 (ii) 90-10 parts by weight of polylactid, opaque blends of polypropylene carbonate with SAN, PS, PP, 0017 (iii) 0.5-15 parts of an additional component that is PMMA (see examples). E.g. U.S. Pat. No. 4,912,149 known to function as an antioxidant, a flame retardant, a describes non-transparent blends of polypropylene carbonate filler, a (metal) complexing agent, a plasticizer or process and PVC. ing aid, pigment, dye, brightener and/or antistatic agent; 0005 Blends of polyhydroxybutyrate (PHB) or polyhy droxybutyrate-covalerate (PHBV) and polypropylene car O bonate are reported in U.S. Pat. No. 6,576,694. The reported b) a second embodiment: blends are, however, non transparent as expected on account 0018 (i) 85-99 parts by weight of polypropylencarbonate of the different solubility parameter as explained above. The having a molecular weight (Mn) between 30,000 and reported blends consist of 30-70 parts of polypropylene car 5,000,000 Da, bonate respectively 70-30 parts of polyhydroxyalkanoates. 0019 (ii) 15-1 parts by weight of polyhydroxyalkanoate, Blends like this were also reported in for example Gaodeng 0020 (iii) 0.1-25 parts of an additional component that is Xuexiao Huaxue Xuebao 2004, 25, 1145 (CA: 141:350588) known to function as an antioxidant, a flame retardant, a or Macromolecular symposia 2004, 210, 241, J. Appl. Chem. filler, a (metal) complexing agent, a plasticizer or process 2004,92,2514-21 or ibid 2003,90,4054-60. All these reports ing aid, pigment, dye, brightener or antistatic agent; are concerned about melting behavior of the PHB, but did not 0021. The second embodiment comprises preferably: find a transparent PPC based material. 0022 (i) 90-98 parts by weight of polypropylencarbonate, 0006. However, there are good reasons for the use of trans 0023 (ii) 10-2 parts by weight of polyhydroxybutyrate, parent materials. They provide appealing qualities in form of 0024 (iii) 0.5-15 parts of an additional component that is attractive design options, direct visual contact to packaged known to function as an an antioxidant, a flame retardant, a US 2009/0234042 A1 Sep. 17, 2009

filler, a (metal) complexing agent, a plasticizer or process and 100, most preferably between 2 and 10. The polypropy ing aid, pigment, dye, brightener or antistatic agent; lene carbonate may also contain up to 1% carbamate or urea O entities. c) a third embodiment comprising mixtures of the first and 0039 Polylactide (PLA) is semi-amorphous with a Tg of second embodiments: around 60° C. and useful in this invention. PLA is a commer 0025 (i) 5-97 parts by weight of polypropylencarbonate, cial available polymer that is based on Substantially enantio 0026 (iia) 80-2 parts by weight of polylactid, meric pure lactic acid (see Nature Works(R) von Cargill Dow). 0027 (iib) 15-1 parts by weight of polyhydroxyalkanoate, Lactic acid is preferentially obtained from an agricultural 0028 (iii) 0.5-15 parts of an additional component that is biological source like Sugar or starch in a fermentative pro known to function as an antioxidant, a flame retardant, a cess. Generally speaking any PLA with a Tg larger than 40° filler, a (metal) complexing agent, a plasticizer or process C. is useful in this invention. The molecular weights are ing aid, pigment, dye, brightener or antistatic agent; preferably in the range of number average Mn between 5,000 0029. The third embodiment comprises preferably: and 5,000,000 Da, preferably between 10,000 and 250,000 0030 (i) 30-97 parts by weight of polypropylencarbonate, Da, most preferably between 25,000 and 150,000 Da. PLA 0031 (iia) 60-2 parts by weight of polylactid, may have been treated prior to its application in this invention 0032 (iib) 10-1 parts by weight of polyhydroxybutyrate, with agents to improve its properties, e.g. like those men 0033 (iii) 0.5-15 parts of an additional component that is tioned by Sinclair R. G. in Pure & Appl. Chem. 1996, A33, known to function as an antioxidant, a flame retardant, a 585-97. filler, a (metal) complexing agent, a plasticizer or process 0040 Polyhydroxyalkanoates embrace preferably poly ing aid, pigment, dye, brightener or antistatic agent; hydroxybutyrate (PHB(V)), particularly preferred poly-3-hy O droxybutyrate (PHB) and polyhydroxybutyrate covaleriate d) a fourth embodiment preferably: (PHBV). Generally speaking, any crystalline PHB(V) is use 0034 (i) 20-80 parts by weight of polypropylencarbonate, ful in this invention when it improves the young modulus of PPC component blend. PHB(V) may be obtained commer 0035 (ii) 60-15 parts by weight of polylactid, cially from e.g. Aldrich. Also copolymers of 3-hydroxybu 0036 (iii) 0.5-15 parts of an additional component that is tyric acid and other hydroxyacids may be used in this inven known to function as an antioxidant, a flame retardant, a tion. A special case of the latter is the copolymer of filler, a (metal) complexing agent, a plasticizer or process 3-hydroxybutyric acid (see Biocycle(R) of PHB Industries) ing aid, pigment, dye, brightener or antistatic agent, and 3-hydroxy Valeric acid, with a maximum of 30% of the 0037 (iv) 20-5 parts by weight of a biodegradable ali latter (see Enmat(R) of Tianan). 4-Hydroxybutyrate as avail phatic or aliphatic/aromatic polyester. able by Metabolix is especially preferred. 0038 Polypropylenecarbonate (PPC) useful in this inven 0041 Aliphatic or aromatic-aliphatic polyesters can be tion is the resulting copolymer of the copolymerization of used as bio-degradable polyesters (component (iv)). Pre carbon dioxide and propylene oxide. The polymer may con ferred elements of the polyesters are: tain both ether and carbonate linkages in the main chain. The percentage of carbonate linkages is dependent on the reaction 0042 aliphatic dicarbonic acids as Succinic, adipic or conditions and for example the nature of the catalyst. Prefer Sebacinic acid, or esters or mixtures thereof, ably the polymer comprises more than an 85 and mostly 0.043 occasionally aromatic dicarbonic acids astereph preferred more than a 90 percentage of carbonate linkages of thalic acid or esters thereof and all linkages between former PO monomer. Several catalyst 0044 diols as 1,4-butanediol or 1,3-propanediol. systems are known that catalyze the copolymerization; for 004.5 Ecoflex(R) (BASF Aktiengesellschaft), Eastar Bio(R) example zinc glutarate as described in U.S. Pat. No. 4,789, and Origo Bi(R) (Novamont), BionolleR (Showa Highpoly 727. Furthermore, PPC can be prepared according to Soga et mers) are preferred bio-degradable polyesters. al., Polymer Journal, 1981, 13, 407-10. A particularly pre 0046. The above polymers may be applied in form of ferred process in preparing high-molecular weight PPC is pellets or powder or be molten prior to blending. The pellets disclosed in WO-A 06/061237. Mn of material obtained by have preferable dimensions of 0.1 to 20 mm, most preferably the above process is about 70-90,000; Mw is 300,000 Da; the between 2 and 7 mm. They may have any shape. The powder ether to carbonate linkage ratio is 7 to 93. The polymer is also commercially available e.g. from empower materials or Ald is preferably in the range of 1-1000 um. rich. This material is also useful in this invention. The PPC 0047. The blends of the invention may contain any anti may have been treated with several agents to improve its oxidant known in the art such as but not limited to hindered properties, for example with anhydrides like MSA, acetic phenols, like IrganoxR) 1010 obtainable from Ciba Speciality anhydride, isocyanates or epoxides The molecular weights of Chemicals or Uvinul R. obtainable from BASF Aktiengesell the PPC are generally in the range of number average Mn schaft. The amount of the anti oxidant(s) used in this inven between 30,000 and 5,000,000 Da, preferably between tion may be about 0.1-2 parts by weight, preferably not 35,000 and 250,000 Da, most preferably between 40,000 and exceeding 1% by weight relative to the blend polymeric com 150,000 Da. PPC of lower molecular weight than about ponents. Mn=25,000 Da suffers from a low glass temperature Tg (<25° 0048. The blends of the invention may contain any plasti C.) and has a too low Young's modulus (Iso 527-2, DIN cizer, as for example phthalates, triethyleneglycol diacetate, 53455: <400 MPa) and a break stress lower than 10 MPa (and citrates, terephthalic esters, adipinic ester, Succinic ester, mal is not very suitable in this invention on account of the low onic ester, maleic ester, etc. entanglement density. The ratio of number average and 0049. Using plasticizers the continuous phase of PPC can weight average molecular weight lies between preferably 1 be extended to a lower PPC content in the blend. US 2009/0234042 A1 Sep. 17, 2009

0050. The blends of the invention may contain any filler 0058. The blends according to the invention comprises Such as caolin, calcium carbonate, talcum, silica, cellulose, blends of polypropylene carbonate and PLA or blends of crayon or starch. Preferred fillers are calcium carbonate and polypropylene carbonate and 1 to 15 parts by weight of PHB starch. (V). These blends are transparent and have improved proper 0051. The blends of the invention may contain any stabi ties compared to PPC with respect to glass temperature and/or lizer in form of an anhydride, diepoxide such as preferred young modulus. Accordingly said blends can be used in many glycidyl-methacrylate (see Joncryl(R) ADR 4368 from new applications such as food packaging in form of sheeting Johnson Polymer) or epoxidized oils such as MerginatR) or containers for Solids or liquids like beverages, or toys as an ESBO from Hobum, Hamburg or Edenol R. B316 vfrom Cog alternative in applications typical for (plasticized) PVC. Also nis, Düsseldorf), caprolacton and/or diisocyanates. The in construction purposes e.g. as an interlayer in between blends also may comprise additional components that window panels. A further advantage of commercial relevance improve its properties e.g. thermal stability, biodegrability, is the fact that the blends and their fragments are hydrolyti resistance to (bio)degradation, burning behavior or process cally- and/or bio-degradable by natural occurring microor ing aids. Also additives like pigments, dyes, brighteners, anti ganisms. static agents (such as ten-sides) and the like may be added. 0059 Foams of the blends according to the invention can 0052 Blends of polypropylene carbonate can be obtained be formed as shown in EP 07102477.2 and EP 07102497.0: by any of several of known methods, for example by combin “foam extrusion principles and practice'. Shau-Tarng Lee, ing Solutions of the blend components or by roller mixing or 376 pages, CRC Press, 2000; “thermoplastic foam extru by compounding in an extruder or kneader and alike. In a sion', James Thorne, Carl Hanser, 2006. The foams have the preferably embodiment, the extrusion and pelletization of the following advantages: blends are performed in an extruder with a single or twin 0060 Translucent, highly light-transmissive foam screw. In yet another preferred embodiment, the blends are Structure prepared by roller mixing of the components. In these cases, 0061 Soft touch—even coextruded the material is molten in the temperature range of 150-230° 0062 Biodegradibility in compost plant C., preferably in the range of 170-200° C. 0063 CO-trap by the use of PPC 0053. In another preferred embodiment, the blend is pre 0064. Useful for food grade applications pared from a solvent. Any solvent dissolving at least one of the components may be used; preferably a solvent is used that 0065 Highly UV-resistant dissolves both components. Preferred solvents include 0.066 Suitable for deep-drawing. dichloromethane, trichloromethane, tetrahydrofurane, 0067 Shortcomings for some applications might be the N-methylpyrrolidon, dimethylsulfoxide, esters like ethyl low temperature resistance and the low hydrolytic stability. acetate, ketones like acetone or methylethylketone. Most pre 0068. The foams can be used as foam trays for meat, fish, ferred are volatile solvents like trichloromethane and tetrahy fruits and vegetables; clampshells for fast food; protective drofurane. films for e.g. products with sensitive Surfaces as consumer 0054 Blends may be processed into a number of forms goods, cars or electronic goods, e.g. television sets, radios, e.g. for transport or processing. Most preferred the blends are mp3 players and cellphones; separation layers for packaging; prepared by compounding on an extruder and the resulting foam trays ant inserts for fruit or vegetable crates; foamed melt Subsequently processed into a strand, which is Subse cleaning cloth or foamed beads for fish boxes quently cut into pellets or milled into a powder. 0069. The blends according to the invention can be per 0055. In order to evaluate the properties of the blends, they fectly used for transparent, rigid or semi-rigid packaging or were processed into sheets of 1 mm thickness and 6.6 cm for displayS. Relevant production processes are disclosed in: area. All blends were transparent by the eye, e.g. by looking “Polymer Extrusion’, Chris Rauwendaal, Carl Hanser, 1986: through against a brighter light or when covering a flat under “Thermoforming, James Thorne, Carl Hanser, 1986; "Ein ground. This is highly Surprising since blends of high molecu führung in die Kunststoffverarbeitung”, Walter Michaeli, lar weight polymers are generally opaque as the result of Carl Hanser, 2006: “Handbuch Spritzgie?Ben”, Friedrich breaking of light at the phase boundaries of the insoluble Johannaber, W. Michaeli, Carl Hanser, 2004; “Blow Molding dispersed components. A transparent blend may result if the Handbook'. Dominik V. Rosato et al., Carl Hanser, 2004; comprising polymers are fully miscible, as it has been "Kunststoff Maschinenführer, Friedrich Johannaber, Carl observed for example in blends of polystyrene and polyphe Hanser, 2004. nylether. This is not the case here, as follows from the fact that 0070. In the field of extrusion of films and thermoforming the blends exhibit glass temperatures close to those of the (inline or off-line) the following applications are particularly components. We find that the blends of PLA and PPC are interesting: cups, lids, trays and straws for catering or take transparent because of matching refractive indices (1.46). away food; transparent packaging for dairy products; trans Thus, although phase boundaries are present in the blend, parent, semi-rigid packaging for sausage including cold cut, light is not scattered. This is also highly surprising. meat, cheese, fish and vegetarian food; food trays; blister 0056. In case of PHB, a crystalline part was obtained with packs for pills, medical products and non-food goods. a melt temperature in the range 150-200°C. with a crystalli 0071. With extrusion-blow-molding e.g. bottles for bever zation temperature in the range of 0 to 80°C., preferable in the ages, cosmetics, detergents, crop protection agents or chemi range of 20-60° C., most preferable in the range of 40-50° C. cals are available. 0057 Pellets of the blends or blends prepared in situ may 0072. With profile extrusion hygiene products like tooth be processed into sheeting, containers or other forms also as brushes, combs, cotton buds, lipstick, brushes; long lines for component of a 2K processing set up using injection or blow the fishery industry; infusion tubes or raffia can be produced. moulding or by rotary molding. Also techniques like deep 0073. Injection blow molding of the blends according to drawing or compression molding could be used. the invention leads inter alia to bottles for beverages (as US 2009/0234042 A1 Sep. 17, 2009

mineral water or soft drinks), cosmetics, detergents, crop late with a carbonate linkages content of 93-95% (by NMR). protection agents or chemicals. Mn=70.000 Da, Mw =320,000 Da. Tg 31-33°C. In another 0074 Film extrusion is disclosed e.g. in “Kunststoff-Fo batch using 1 kg of Zinc glutarate to prepare 10 kg of PPC, a lien Herstellung-Eigenschaften-Anwendung. Joachim material with Mn=42,000 and Mw =200,000 Da was Nentwig, Carl Hanser, 2001. By this process the blends obtained. according to the invention are transformed to: films for I0083 Polypropylene carbonate (PPC) could also be hygiene applications; e.g. back sheets for nappies, lady care obtained commercially from empower materials with a car products; bags for fruits and vegetables; carrier bags, shop bonate content of about 98, Mw of 250.000 Da and a glass pers; compost bags; waste bags; peelable lidding film—trans temperature of 40°C. parent or opaque — weldable lidding films—transparent or I0084 PLA was obtained from Cargill Dow (Nature(R) opaque —; shrink film, sausage casings, salad films, stretch Works 4041 D): film (cling film) for fruits and vegetables, meat and fish; I0085 PHB was obtained from PHB Industries (Bio stretch film for pallet wrap; films for nets. cycle R1000). 0075. Due to the excellent barrier properties the blends I0086 Mechanics (elongation at break) were determined according to the invention are predestinated for packing of according to ISO 527-2. meat, poultry, meat products, processed meat, sausages; Sea food, fish, crab meat; cheese, processed cheese; desserts; Preparation of PPC/PLA Blends. pastry, e.g. with meat, fish, poultry, tomato; bread, biscuits, Blend Preparation Using Solvents bakery products; fruits, fruit juices, vegetables, tomato paste, salads; pet food; pharmaceuticals; coffee, coffee-like prod Example 1 ucts; milk- or chocolate powder, coffee creamers, baby food; I0087 PPC (20g) was dissolved in 80 g of chloroform and dehydrated food; jams and jellies; spreads, chocolate paste; mixed with solution of PLA (20g) in 80 g of chloroform. The menus. For more detailed information see the reference resulting clear Solution was evaporated to dryness in a “Food Processing Handbook”, James G. Brennan, Wiley vacuum. The blend was isolated as a transparent material with VCH, 2005. few gas bubbles. After cutting, the material was pressed into 0.076 A detailed review regarding packaging technology a sheet of 1 mm thickness at 180°C. using pressure of 200bar. is shown in references: “Food Packaging Technology”. Rich pressing time 8 min. It is transparent by the eye. Highest Tg ard Coles, Derek McDowell, Mark; Blackwell Publisching, was determined at 50° C. CNC Press, 2003 and “Wursthillen Kunstdarm-Herstellung Eigenschaften, Anwendung, Gerhard Effenberger, Holz Example 2 to 4 mann Verlag, 1991. Starting from the blends according to the I0088. By the same procedure blends with a weight per invention e.g. modified atmosphere packaging, transparent centage of 70% (example 2), 40% (example 3) and 20% barrier films, boilable and sterilisable films and non-metal (example 4) PPC were obtained. All blends were transparent barrier films are available. by visual inspection. 0077. The blends according to the invention are also useful I0089 GPC measurements of blend of examples 1 to 4 for the following applications: e.g. bowls, beakers, utensils, showed that no breakdown of molecular weight had taken washing machines, cooking machines, (garden) furniture, place, rather a Superposition of the individual components television sets, radios, mp3 players, cell phones, children's was obtained (Mn=70 to 90 kDa, Mw =300 kDa). Highest Tg toys, like for example playing balls, sand molds, shovels, was found at 50° C. rakes, pawns, dices, rattlers, toy cars, three wheelers, bicycles, and also equipment used in table-top games like Comparison Example 5 and 6 balls and protective wear. 0090 These examples show that blends of polypropylene 0078 Because of the design options the blends are useful carbonate with polymers of comparable solubility parameter for hygiene products like toothbrushes, combs, Q tips, lip are not transparent. Stick or brushes, extruded piping for garden hoses 2 and (0091. In example 5, 20g of PS was dissolved in 80 g of 3-dimensional works of art etc. chloroform and mixed with 20 g of polypropylene carbonate 0079. Due to the interesting haptic behavior the blends dissolved in 80 g of chloroform. according to the invention can be used in footwear, e.g. soles, 0092. In example 6, 20 g of Ecoflex(R) from BASF in lays, in lays for ski boots, knee pads, epaulettes and in lays Aktiengesellschaft (a copolyester of adipinic acid, 1,4-bu in bras or other sport, cosmetic or medical products. tanediol and terephthalic acid) was dissolved in 80 g of chlo 0080. The blends may also be formed into fibers e.g. by a roform and mixed with 20 g of PPC dissolved in 80 g of spinning process for the preparation of garments, bet sheets or chloroform. Both the mixed solutions of example 5 and 6 blankets. were not fully clear. The dried sheets were fully intransparent as well as the compression molded sheets of 1 mm thickness EXAMPLES thereof. DSC measurements showed glass transitions coinci 0081. In the examples the following materials were used: dent with those of the components (PS: 101° C., Ecoflex-39° 0082 Polypropylene carbonate was obtained by copoly C.). merizing PO and CO, at 80°C. in a 1:2 mixture with toluene Blend Preparation by Roller Mixing and using Zinc glutarate (1 kg catalyst was used for the prepa ration of 20-50 kg polymer) as catalyst at 50 bar pressure in a Examples 7 and 8 100 L reactor (see also WO 06/061237). The resulting slurry (0093 Rolls were heated to 180° C. roller mixing was was diluted with ethyl acetate and extracted with water con performed for at least 8 minutes or until individual phases taining over 5% acetic acid. PPC was isolated from the were no longer observable (max of 15 min). A total of 101g organic phase with the aid of an extruder to give clear granu was used consisting of 1% Irganox 1010 stabilizer and 60 g US 2009/0234042 A1 Sep. 17, 2009

PPC and 40 g PLA in example 7 and 1% Irganox 1010 stabilizer and 40% PPC and 60% PLA in example 8. In both cases, a clear sheet results that is tough and not tacky to metal, Polypropylene wood and skin. DSC measurements showed that a mixing of carbonate PHB phases was not measurable as two glass transition at 35° C. Experiment (weight%) (weight%) DSC and 59° C. are found, almost identical to those of PPC PLA, respectively. The sheets were cut into smaller pieces (+50 13 90 10 Tm 171, Tg 0° C., Tg 32° C. 100 mm) and subjected to compression molding. Transpar 14 95 5 Tm 183/179, Tg -4° C., ent sheets of 1 mm thickness were obtained. These were Tg 30° C. colorless, tough and stiff and not tacky. 15 98 2 ind Blend Preparation by Compounding in an Extruder 0099. These data show, that two phases are present, one Examples 9 to 11 has the characteristics of PHB, increasing the elastic modulus of the blend on account of the crystalits with Tm=170-180° 0094. Blends of PPC and PLA were prepared by com C., and PPC basically its parent form. pounding in an extruder of the mini molder type with return flow. In a typical experiment, 11 g of polymer were used. The Example 16 to 18 processing temperature was set at 190° C. (180° C. at the entrance). The blend was prepared using the mini molder 0100. As described under example 9, a blend was prepared during 3 to 5 minutes. The hot melt was injection molded into from polypropylene carbonate and PHB, with the addition of a dumbbell with 10-15 bar of pressure at 50° C. Latter were 1% of Irganox 1010 by weight based upon the total weight of easily demolded and Subjected to mechanical measurements. the polymers. The resulting melt was used for injection mold 0095 Experiment 9 consisted of 75% polypropylene car ing to prepare dumbbells. These were evaluated. The material bonate, 25% (by weight) PLA, Experiment 10 was a 50:50 properties are listed in the below table. mixture of polypropylene carbonate/PLA by weight and experiment 11 was a 25% polypropylene carbonate and 75% PLA. All blends were transparent and colorless. The results Polypropylene show, that the modulus increases and favorably for the appli carbonate PHB Emod Stress at cations listed above. Experiment (weight%) (weight%) (MPa) break** 16 90 10 1080 37 17 95 5 870 29 18 98 2 ind 5 StreSS at PPC by PLA by break *(Measured according to ISO 527-2, Experiment weight% weight % Emod (MPa)* (MPa)** **DIN 53455) 9 75 25 n.d. 14 10 50 50 2OOO 38 0101 The Young modulus increased from 600 to about 11 25 75 2700 50 1000 MPa. The composition allows one to adjust the modu 1OO 600 6 lus. *according to ISO 527-2, 1-12. (canceled) **DIN 53455) 13. A transparent blend comprising 0096. The mechanical properties were measured: the elas i) 1 to 99 parts by weight of polypropylencarbonate having tic modulus had increased from about 600 to 3500 MPa, and a number molecular weight (Mn) of from 30,000 to could be adjusted with the composition. Furthermore, the 5,000,000 Da and a Young's modulus of at least 400 resistance to break was significantly increased. Several glass Mpascal; transitions Tg of the blends were found, the highest decisive ii) 99 to 1 parts by weight of polylactid; and for the Emod was found at 58° C. iii) 0.1 to 25 parts of an antioxidant, a flame retardant, a filler, a (metal) complexing agent, a plasticizer or pro Preparation of PPC/PHB Blends cessing aid, a pigments, a dye, a brightener, an antistatic agent, or combinations thereof; Comparison Experiment 12 wherein the sum of the parts of said polypropylencarbonate 0097. A blend using 20% of PHB and 80% of PPC was and said polylactid is 100 parts by weight. prepared using roller mixing as described in example 7. Mix 14. A transparent blend comprising ing time was 8 minutes and temperature was 180° C. The i) 85 to 99 parts by weight of polypropylencarbonate hav resulting sheet was easily removed and nontransparent after ing a number molecular weight (Mn) of from 30,000 to 5,000,000 Da and a Young's modulus of at least 400 visual inspection. Mpascal; Example 13 to 15 ii) 15 to 1 parts by weight of polyhydroxyalkanoates: iii) 0.1 to 25 parts of an antioxidant, a flame retardant, a 0098. As described in experiment 12, blends of PPC and a filler, a (metal) complexing agent, a plasticizer or pro lower content of PHB were prepared using roller mixing. In cessing aid, a pigments, a dye, a brightener, an antistatic all experiments, Irganox 1010, 1% by weight based on the agent, or combinations thereof; sum of weights of PPC and PHB was added. The next table wherein the sum of the parts of said polypropylencarbonate shows the results. and said polylactid is 100 parts by weight. US 2009/0234042 A1 Sep. 17, 2009

15. The transparent blend of claim 13, wherein said cessing aid, a pigments, a dye, a brightener, an antistatic polypropylencarbonate has a number molecular weight Mn agent, or combinations thereof of from 35,000 to 250,000 g/mol Da. wherein the sum of the parts of said polypropylencarbon 16. The transparent blend of claim 13, wherein said ate, said polylactid, and said polyhydroxybutyrate is 100 polypropylencarbonate has a break stress of at least 10 MPas parts by weight. cal. 20. The transparent blend of claim 13, wherein said trans 17. The transparent blend of claim 13, wherein the C-units parent blend is prepared using an extruder, by kneader or of said polypropylencarbonate are from 90% to 100% linked roller mixing, by compression, or by extrusion blow mould via a carbonate group. 1ng. 21. A slow release matrix for use in agricultural and medi 18. The transparent blend of claim 13, wherein said trans cal applications comprising the transparent blend of claim 13. parent blend comprises a stabilizer, a plasticizer, and/or a 22. A packaging, a toy, a sporting good, a hygiene product, filler a household product, a medical product, a cosmetic product, 19. A transparent terblend comprising an electronic appliance, an electric appliance, or an optical (i) 30 to 97 parts by weight of polypropylencarbonate; device comprising the transparent blend of claim 13. (iia) 60 to 2 parts by weight of polylactid: 23. A barrier packaging or a semi-rigid packaging com (iib) 10 to 1 parts by weight of polyhydroxybutyrate; and prising the transparent blend of claim 13. (iii) 0.5 to 15 parts of an antioxidant, a flame retardant, a filler, a (metal) complexing agent, a plasticizer or pro c c c c c