使用四異丙基鈦為觸媒，藉由兩階段（酯化與聚縮合）反應，合成聚丁二酸二丁酯(PBSu)、聚丁二酸二乙酯(PESu)、聚丁二酸二丙酯(PPSu)、聚丁二酸甲基二丙酯(PMPSu)及三種系列的共聚酯PBPSu、PBMPSu與PEBSu。透過本質黏度與凝膠滲透層析儀(GPC)的量測，可得到所合成聚酯的分子量。所合成的聚酯其本質黏度約為0.97 ~ 1.62 dL/g，相對分子量約為2.4x10000 ~ 11.9x10000 g/mol，聚酯可以很容易壓製成膜。共聚酯的組成與鏈段分佈可由核磁共振儀(NMR)氫譜與碳譜測得，這些共聚酯的亂度值均趨近於1.0，顯示共聚單體在共聚酯鏈段序列分佈是屬於無規則分佈。
共聚酯的熱性質與熱穩定性分別使用微差式掃瞄熱卡計(DSC)與熱重分析儀(TGA)來測量，所有的共聚酯皆僅有一個玻璃轉移溫度(Tg)。PBPSu共聚酯隨著丁二酸二丙酯(PS)單元導入，不僅縮減了玻璃轉移溫度與熔點(Tm)的差距，亦降低其冷結晶的能力，從而使其結晶度降低。將丁二酸甲基二丙酯(MPS)單元與丁二酸二丁酯(BS)單元分別導入PBSu與PESu，可發現PBMPSu與PEBSu共聚酯也有此現象產生。熱分解啟始溫度為熱重損失微分曲線可偵測到變化的初始溫度，所有聚酯的熱分解啟始溫度大都約在240 οC，明顯高於聚縮合反應的溫度(220 οC)，顯示在合成這些聚酯的過程並沒有使用熱穩定劑的必要性。此外，同系列的共聚酯其熱穩定性與組成沒有明顯變化。
聚酯在低於熔點5-20 οC下等溫結晶所得的試片，在室溫下以X射線繞射儀量測，由共聚酯的WAXD圖譜可知將PS或MPS單元導入PBSu，會明顯抑制PBSu的結晶行為。而當BS單元導入PESu聚酯時，此現象也發生在PEBSu共聚酯。根據X射線繞射儀與DSC的量測結果，PMPSu為一非晶態的聚酯，顯示高分子鏈上的甲基取代基對結晶的抑制作用具有效果。

Three series copolyesters [poly(butylene succinate-co-propylene succinate) (PBPSu), poly(butylene succinate-co-2-methyl-1,3-propylene succinate) (PBMPSu) and poly(ethylene succinate-co-butylene succinate) (PEBSu)] and their homopolyesters [poly(butylene succinate) (PBSu), poly(ethylene succinate) (PESu), poly(propylene succinate) (PPSu) and poly(2-methyl-1,3-propylene succinate) (PMPSu)] were synthesized by a two-step reaction (esterification and polycondensation) with titanium tetraisopropoxide as the catalyst. Molecular weights of all synthesized polyesters were determined by intrinsic viscosity and gel permeation chromatography (GPC) measurements. The values of intrinsic viscosity (0.97 ~ 1.62 dL/g) and relative molecular weight (2.4x10000 ~ 11.9x10000 g/mol) indicate that these polyesters can be made into films without complications. Compositions and sequence distributions of copolyesters were determined by analyzing the spectra of 1H NMR and 13C NMR. The randomness values of these copolyesters are closed to 1.0 that represents random sequence distribution of the comonomers.
Thermal properties and stabilities were characterized using differential scanning calorimeter (DSC) and thermogravimetric analyzer (TGA), respectively. All copolyesters exhibited a single glass transition temperature (Tg). For PBPSu copolyesters, incorporating propylene succinate units to PBSu not only narrows the window between Tg and melting temperature (Tm), but also retards the cold crystallization ability, thereby lowering the crystallinity to a considerable extent. This phenomenon also occurred in PBMPSu and PEBSu copolyesters when the 2-methyl-1,3-propylene succinate (MPS) and butylene succinate (BS) units were incorporated into PBSu and PESu, respectively. Tstart is the temperature of first detectable deviation from the derivative curve of weight loss. Tstarts of all synthesized polyesters around 240 οC, higher than the temperature of polycondensation reaction (220 οC), demonstrates that there is no necessity of using a thermal stabilizer during the synthesis of these polyesters. Additionally, the thermal stability does not vary significantly with compositions in the same series polyester.
Wide-angle X-ray diffractograms (WAXDs) at room temperature were obtained from polyesters crystallized isothermally at a temperature around 5-20 οC below their melting temperatures. WAXD patterns of two series polyesters elucidated that the incorporation of PS or MPS units into PBSu markedly inhibits the crystallization behavior of PBSu. The phenomenon also occurred in PEBSu copolyesters when BS units were incorporated into PESu. Results of WAXD and DSC measurements showed that PMPSu is a amorphous polyester. The retarding effect on crystallization by methyl substituents on the polymer chain is efficient.

Contents
致 謝………………………………………………………………….………………I
Abstract……………………………………………………………………………......II
摘 要...…………………………………………………………………….……….IV
Contents…………….……………………………………………………………….V
List of Schemes..……………………………………………………….………….VII
List of Tables……………………………………………………………………….VIII
List of Figures………………………………………………………………………. IX
Chapter 1 Introduction……………………………..……………………………....…1
1.1 Background……………………………………………………………….1
1.2 Purposes of this study…………………………………………………….5
Chapter 2 Literature review………………………………………………………......7
2.1 Synthesis of polyesters……………………………………………………7
2.2 Biodegradability of aliphatic polyesters………………………………….7
2.3 Applications…….………………….……………………………………11
Chapter 3 Experimental…………………………………………………..…………12
3.1 Materials…..………………………………………………………….…12
3.2 Synthesis of polyesters….………………………………………….……12
3.2.1 PBSu, PPSu and PBPSu copolyesters…...…………………….……12
3.2.2 PMPSu and PBMPSu copolyesters……...…………………….……13
3.2.3 PESu and PEBSu copolyesters………..….…………………………14
3.3 Measurements of molecular weights…...……………………………….14
3.4 Measurements of intrinsic viscosity....………………………………….14
3.5 NMR analyses..………………………...……………………………….15
3.6 Preparation of specimens………………………………………………..15
3.7 Measurements of thermal properties…...……………………………….16
3.8 Measuring thermal stability……....………….………………………….16
3.9 Wide-angle X-ray diffraction measurements..………………………….16
Chapter 4 Results and discussion…………………………..…………………..……18
4.1 Modifications for polymerization……………………………………….18
4.2 PBPSu series polyesters………………………………………………...19
4.2.1 Intrinsic viscosity and molecular weight of PBPSu polyesters…..... 19
4.2.2 1H and 13C NMR analysis of homopolyesters………………………20
4.2.3 1H and 13C NMR analysis of PBPSu copolyesters………………….20
4.2.4 Thermal properties of PBPSu polyesters……………………………23
4.2.5 Thermal stability of PBPSu polyesters……………………………...24
4.2.6 Wide angle X-ray diffraction patterns of PBPSu polyesters……...25
4.3 PBMPSu series polyesters………………………………………………25
4.3.1 Intrinsic viscosity and molecular weight of PBMPSu polyester…..25
4.3.2 1H and 13C NMR analysis of PBMPSu copolyesters...…………..…26
4.3.3 Thermal properties of PBMPSu polyesters…………………………28
4.3.4 Thermal stability of PBMPSu polyesters………………...…………30
4.3.5 Wide angle X-ray diffraction patterns of PBMPSu polyesters…..….31
4.4 PEBSu series polyesters………………………………………………...32
4.4.1 Intrinsic viscosity and molecular weight of PBMPSu polyesters…32
4.4.2 1H and 13C NMR analysis of PEBSu copolyesters…………………32
4.4.3 Thermal properties of PEBSu polyesters…………………………...34
4.4.4 Comparison of thermal properties of homopolyesters……………...36
4.4.5 Thermal stability of PEBSu polyesters……………………………..36
4.4.6 Wide angle X-ray diffraction patterns of PEBSu polyesters………..37
Chapter 5 Conclusions………………………………………………………………38
References……………………………………………………………………………40
Publications……………………………………………………………………….….94

[1] Chandra R, Rustgi R. Biodegradable polymers. Prog Polym Sci 1998;23:1273- 1335.
[2] Mochizuki M, Hirami M. Structural effects on the biodegradation of aliphatic polyesters. Polym Adv Technol 1997;8:203-209.
[3] Carothers WH. Polymerization. Chem Rev 1931;8:353-425.
[4] Doi Y, Steiunbchel A. Biopolymers, vol. 3b. Wiley-VCH Verlag. Weinheim, Germany, 2001, chapter 10.
[5] Takiyama E, Harigai N, Hokari T. Production of aliphatic polyester. JP Patent H5-70566, Mrach 23; 1993.
[6] Takiyama E, Seki S. Production of aliphatic polyester. JP Patent H5-70572, March 23; 1993.
[7] Takiyama E, Fujimaki T, Seki S, Hokari T, Hatano Y. Method for manufacturing biodegradable high molecular aliphatic polyester. US Patent 5,310,782, May 10; 1994.
[8] Takiyama E, Hatano Y, Fujimaki T, Seki S, Hokari T, Hosogane T, Harigai N. Method of producing a high molecular weight aliphatic polyester and film thereof. US Patent 5,436,056, July 25; 1995.
[9] Fujimaki T. Processability and properties of aliphatic polyesters, “BIONOLLE”, synthesized by polycondensation reaction. Polym Degrad Stab 1998;59:209-214.
[10] Kumagai Y, Kanesawa Y, Doi Y. Enzymatic degradation of microbial poly(3-hydroxybutyrate) films. Makromol Chem Phys 1992;193:53-57.
[11] Abe H, Doi Y, Aoki H, Akehata T. Solid–state structures and enzymatic degra- dabilities for melt-crystallized films of copolymers of (R)-3-hydroxybutyric acid with different hydroxyalkanoic acids. Macromolecules 1998;31:1791-1797.
[12] Gan Z, Abe H, Doi Y. Crystallization, melting, and enzymatic degradation of biodegradable poly(butylene succinate-co-14 mol % ethylene succinate) copolyester. Biomacromolecules 2001;2:313-321.
[13] Gan Z, Abe H, Kurokawa H, Doi Y. Solid-state microstructures, thermal properties, and crystallization of biodegradable poly(butylene succinate) (PBS) and its copolyesters. Biomacromolecules 2001;2:605-613.
[14] Ahn BD, Kim SH, Kim YH, Yang JS. Synthesis and characterization of the biodegradable copolymers from succinic acid and aliphatic acid with 1,4-butanediol. J Appl Polym Sci 2001;82:2808-2826.
[15] Nikolic MS, Djonlagic J. Synthesis and characterization of biodegradable poly(butylene succinate-co-butylene adipate)s. Polym Degrad Stab 2001;74: 263-270.
[16] Kuwabara K, Gan Z, Nakamura T, Abe H, Doi Y. Molecular mobility and phase structure of biodegradable poly(butylene succinate) and poly(butylene succinate- co-butylene adipate). Biomacromolecules 2002;3:1095-1100.
[17] Zhu C, Zhang Z, Liu Q, Wang Z, Jin J. Synthesis and biodegradation of aliphatic polyesters from dicarboxylic acids and diols. J Appl Polym Sci 2003;90:982-990.
[18] Cao A, Okamura T, Nakayama K, Inoue Y, Masuda T. Studies on syntheses and physical properties of biodegradable aliphatic poly(butylene succinate-co- ethylene succinate)s and poly(butylene succinate-co-diethylene glycol succinate)s. Polym Degrad Stab 2002;8:107-117.
[19] Cao A, Okamura T, Ishiguro C, Nakayama K, Inoue Y, Masuda T. Studies on syntheses and physical characterization of biodegradable aliphatic poly(butylene succinate-co-ε-caprolactone)s. Polymer 2002;43:671-679.
[20] Kim MN, Kim KH, Jin HJ, Park JK, Yoon JS. Biodegradability of ethyl and n-octyl branched poly(ethylene adipate) and poly(butylene succinate). Eur Polym J 2001;37:1843-1847.
[21] Chae HG, Park SH, Kim BC, Kim DK. Effect of methyl substitution of the ethylene unit on the physical properties of poly(butylene succinate). J Polym Sci Part B: Polym Phys 2004;42:1759-1766.
[22] Oishi A, Nakano H, Fujita K, Yuasa M, Taguchi Y. Copolymerization of poly(butylene succinate) with 3-alkoxy-1,2-propanediols. Polym J 2002;34:742- 747.
[23] Mani R, Bhattacharya M, Leriche C, Nie L, Bassi S. Synthesis and characterization of functional aliphatic copolyesters. J Polym Sci Part A: Polym Chem 2002;40:3232-3239.
[24] Nikolic MS, Poleti D, Djonlagic J. Synthesis and characterization of biodegradable poly(butylene succinate-co-butylene fumarate)s. Eur Polym J 2003;39:2183-2192.
[25] Mochizuki M, Mukai K, Yamada K, Ichise N, Murase S, Iwaya Y. Structure effects upon enzymatic hydrolysis of poly(butylene succinate-co-ethylene succinate)s. Macromolecules 1997;30:7403-7407.
[26] Rizzarelli P, Puglisi C, Montaudo G. Soil burial and enzymatic degradation in solution of aliphatic co-polyesters. Polym Degrad Stab 2004;85:855-863.
[27] Iwata T, Doi Y, Isono K, Yoshida Y. Morphology and enzymatic degradation of solution-grown single crystals of poly(ethylene succinate). Macromolecules 2001;34:7343-7348.
[28] Cho K, Lee J, Kwon K. Hydrolytic degradation behavior of poly(butylene succinate)s with different crystalline morphologies. J Appl Polym Sci 2001;79: 1025-1033.
[29] Traub HL, Hirt P, Herlinger H, Oppermann W. Synthesis and properties of fiber-grade poly(trimethylene terephthalate). Die Angew Makromol Chem 1995; 230:179-187.
[30] Walter T, Augusta J, Muller RJ, Widdecke H, Klein J. Enzymatic degradation of a model polyester by lipase from rhizopus delemar. Enzyme Microb Technol 1995;17:218-224.
[31] Ranucci E, Liu Y, Lindblad MS, Albertsson AC. New biodegradable polymers from renewable sources: High molecular weight of poly(ester carbonate)s from succinic acid and 1,3-propanediol. Macromol Rapid Commun 2000;21:680-684.
[32] Liu Y, Ranucci E, Lindblad MS, Albertsson AC. New segmented poly(ester- urethane)s from renewable resources. J Polym Sci Part A Polym Chem 2001; 39:630-639.
[33] Liu Y, Ranucci E, Lindblad MS, Albertsson AC. New biodegradable polymers from renewable sources: Polyester-carbonates based on 1,3-propylene-co-1,4- cyclohexanedimethylene succinate. J Polym Sci Part A Polym Chem 2001;39: 2508-2519.
[34] Liu Y, Ranucci E, Lindblad MS, Albertsson AC. New biodegradable polymers from renewable sources: Segmented copolyesters of poly(1,3-propanediol succinate) and poly(ethylene glycol). J Bioact Compat Polym 2002;17:209-219.
[35] Papageorgiou GZ, Bikiaris DN. Crystallization and melting behavior of three poly(alkylene succinates). A comparative study. Polymer 2005;46:12081-12092.
[36] Bikiaris, DN, Papageorgiou GZ, Achilias DS. Synthesis and comparative biodegradability studies of three poly(alkylene succinate)s. Polym Degrad Stab 2006;91:31-43.
[37] Papageorgiou GZ, Bikiaris DN. Biodegradable poly(alkylene succinate) blends: thermal behaviour and miscibility study. J Polym Sci Part B: Polym Phys 2006; 44:584-597.
[38] Soccio M, Finelli L, Lotti N, Gazzano M, Munari A. Poly(propylene isophthalate), poly(proplyene succinate), and their random copolymers: Synthesis and thermal properties. J Polym Sci Part B Polym Phys 2007;45: 310-321.
[39] Umare SS, Chandure AS, Pandey RA. Synthesis, characterization and biodegradable studies of 1,3-propanediol based polyesters. Polym Degrad Stab 2007;92:464-479.
[40] Tsai CJ, Chang WC, Chen CH, Lu HY, Chen M. Synthesis and characterization of polyesters derived from succinic acid, ethylene glycol and 1,3-propanediol. Eur Polym J 2008;44:2339-2347.
[41] Sullivan CJ, Dehm DC, Reich EE, Dillon ME. Polyester resins based upon 2-methyl-1,3-propanediol. J Coat Technol 1990;62:37-45.
[42] Bello P, Bello A, Riande E. Conformational characteristics and crystalline order in poly(2-methyl-1,3-propane glycol terephthalate). Macromolecules 1999;32: 8197–8203.
[43] Nalampang K, Johnson AF. Kinetics of polyesterification: modelling and simulation of unsaturated polyester synthesis involving 2-methyl-1,3- propanediol. Polymer 2003;44:6103-6109.
[44] Suh J, Spruiell JE, Schwartz SA. Melt spinning and drawing of 2-methyl-1,3- propanediol-substituted poly(ethylene terephthalate). J Appl Polym Sci 2003;88: 2598-2606.
[45] Lewis CL, Spruiell JE. Crystallization of 2-methyl-1,3-propanediol substituted poly(ethylene terephthalate). I. Thermal behavior and isothermal crystallization. J Appl Polym Sci 2006;100:2592-2603.
[46] Huang YJ, Jiang WC. Effects of chemical composition and structure of unsaturated polyester resins on the miscibility, cured sample morphology and mechanical properties for styrene/unsaturated polyester/low-profile additive ternary systems: 1. Miscibility and cured sample morphology. Polymer 1998;39: 6631-6641.
[47] Huang YJ, Chen LD. Effects of chemical composition and structure of unsaturated polyester resins on the miscibility, cured sample morphology and mechanical properties for styrene/unsaturated polyester/low-profile additive ternary systems: 2. Mechanical properties. Polymer 1998;39:7049-7059.
[48] Kharas GB, Kamenetsky M, Simantirakis J, Beinlich KC, Rizzo AMT, Caywood GA, Watson K. Synthesis and characterization of fumarate-based polyesters for use in bioresorbable bone cement composites. J Appl Polym Sci 1997;66:1123- 1137.
[49] Kharas GB, Villasenor G, Diener CA, Baugh M, Mccolough K, Mikach S, III AS, Whitesell J, Watson K. Synthesis and characterization of fumarate copolyesters for use in bioresorbable bone cement compositions. J Macromol Sci, Pure Appl Chem 2006;43:855-863.
[50] Diakoumakos CD, Jones FN. Studies on the chemical, physical and mechanical properties of high-solids clearcoats prepared from hydroxyl-terminated isophthalate-based oligoesters and a melamine resin. Surf Coat Technol 2001; 140:183-194.
[51] Song DK, Sung YK. Synthesis and characterization of biodegradable poly(1,4- butanediol succinate). J Appl Polym Sci 1995;56:1381-1395.
[52] Yoo Y, Ko MS, Han SI, Kim TY, IM S, Kim DK. Degradation and phsical properties of aliphatic copolyesters derived from mixed diols. Polym J 1998;30: 538-545.
[53] Montaudo G, Rizzarelli P. Synthesis and enzymatic degradation of aliphatic copolyesters. Polym Degrad Stab 2000;70:305-314.
[54] Umemoto S, Kobayashi N, Okui N. Molecular weight dependence of crystal growth rate and its degree of supercooling effect. J Macromol Sci Part-B Phys 2002;B41:923-938.
[55] Oishi A, Zhang M, Nakayama K, Masuda T, Taguchi Y. Synthesis of poly(butylene succinate) and poly(ethylene succinate) including diglycollate moiety. Polym J 2006;38:710-715.
[56] Aburto J, Alric I, Thiebaud S, Borredon E, Bikiaris D, Prinos J and Panayiotou C. Synthesis, characterization, and biodegradability of fatty-acid of amylose and starch. J Appl Polym Sci 1999;74:1440-1451.
[57] Lenz RW; Marchessault R. Bacterial polyesters: Biosynthesis, biodegradable plastics and biotechnology. Biomacromolecules 2005;6:1-8.
[58] Qiu Z, Ikehara T, Nishi T. Crystallization behavior of biodegradable poly(ethylene succinate) from the amorphous state. Polymer 2003;44:5429-5437.
[59] Patel M, Crank M, Marscheider-Weidemann F, Schleich J, Hüsing B; Angerer G. Techno-economic feasibility of large-scale production of bio-based polymers in Europe (PRO-BIP), 2004.
[60] Siracusa V, Rocculi P, Romani S, Rosa MD. Biodegradable polymers for food packaging: a review. Trends Food Sci Technol 2008;19:634-643.
[61] Xu YX, Xu J, Sun YB, Liu DH, Guo BH, Xie XM. Crystallization behavior of poly(butylene succinate-co-propylene succinate)s. Acta Polym Sin 2006;8:1000- 1006.
[62] Xu YX, Xu J, Guo BH, Xie XM. Crystallization kinetics and morphology of biodegradable poly(butylene succinate-co-propylene succinate)s. J Polym Sci Part B Polym Phys 2007;45:420-428.
[63] Xu YX, Xu J, Liu DH, Guo BH, Xie XM. Synthesis and characterization of biodegradable poly(butylene succinate-co-propylene succinate)s. J Appl Polym Sci 2008;109:1881-1889
[64] Papageorgiou GZ, Bikiaris DN. Synthesis, cocrystallization, and enzymatic degradation of novel poly(butylene-co-propylene succinate) copolymers. Biomacromolecules 2007;8:2437-2449.
[65] Chen CH, Lu HY, Chen M, Peng JS, Tsai CJ, Yang CS. Synthesis and characterization of poly(ethylene succinate) and its copolyesters containing minor amounts of butylene succinate. J Appl Polym Sci 2009;111:1433-1439.
[66] Yamadera R, Murano M. The determination of randomness in copolyesters by high resolution nuclear magnetic resonance. J Polym Sci Part A-1: Polym Chem 1967;5:2259-2268.
[67] Newmark RA. Sequence distribution in polyethylene/tetramethylene terephthalate copolyesters by 13C NMR. J Polym Sci Polym Chem 1980;18:559- 563.
[68] Ko CY, Chen M, Wang HC, Tseng IM. Sequence distribution, crystallization and melting behavior of poly(ethylene terephthalate-co-trimethylene terephthalate) copolyesters. Polymer 2005;46:8752-8762.
[69] Backson SCE, Kenwright AM, Richards RW. A 13C NMR study of transesterification in mixtures of poly(ethylene terephthalate) and poly(butylene terephthalate). Polymer 1995;36:1991-1998.
[70] Chatani Y, Hasegawa R, Tadokoro H. Polym Prepr Jpn 1971;20:420.
[71] Ichikawa Y, Suzski J, Washiyama J, Moeki Y, Noguchi K, Okuyama K. Strain- induced crystal modification in poly(tetramethylene succinate). Polymer 1994; 35:3338-3339.
[72] Ichikawa Y, Suzski J, Washiyama J, Moeki Y, Noguchi K, Okuyama K. Crystal transition mechanisms in poly(tetramethylene succinate). Polym J 1995;27:1230- 1238.
[73] Ihn KJ, Yoo ES, Im SS. Structure and morphology of poly(tetramethylene succinate) crystals. Macromolecules 1995;28:2460-2464.
[74] Ichikawa Y, Kondo H, Igarashi Y, Noguchi K, Okuyama K, Washiyama J. Crystal structures of α and β forms of poly(tetramethylene succinate). Polymer 2000;41:4719-4727.
[75] Chen CH, Peng JS, Chen M, Lu HY, Tsai CJ, Yang CS. Synthesis and characterization of poly(butylene succinate) and its copolyesters containing minor amounts of propylene succinate. Colloid Polym Sci 2010;288:731-738.
[76] Alexander LE, X-ray diffraction methods in polymer science. Krieger: Huntington, NY, pp 423 (1969).
[77] Fuller CS, Erickson CL. An x-ray study of some linear polyesters. J Am Chem Soc 1937;59:344-351.
[78] Bunn CW. Molecular structure and rubber-like elasticity II. The stereochemistry of chain polymers. Proc R Soc 1942;A180:67-81.
[79] Ueda AS, Chatani Y, Tadokoro H. Structure studies of polyesters. IV. molecular and crystal structures of poly(ethylene succinate) and poly(ethylene oxalate). Polym J 1971;2:387-397.
[80] Ichikawa Y, Washiyama J, Moteki Y, Noguchi K, Okuyama K. Crystal modification in poly(ethylene succinate). Polym J 1995;27:1264-1266.
[81] Jin HJ, Lee BY, Kim MN, Yoon JS. Properties and biodegradable of poly(ethylene adipate) and poly(butylene succinate) containing styrene glycol units. Eur Polym J 2000;36:2693-2698.
[82] Tserki V, Matzinos P, Pavlidou E, Vachliotis D, Panayiotou C. Biodegradable aliphatic polyesters. Part I. Properties and biodegradation of poly(butylene succinate-co-butylene adipate). Polym Degrad Stab 2006;91:367-376.