Effects of L‐phenylalanine as a nucleation agent on the nonisothermal crystallization, melting behavior, and mechanical properties of poly(3‐hydroxybutyrate‐co‐3‐hydroxyhexanoate)

Poly(3-hydroxybutyrate-co-3-hydroxyhexa- noate) (PHBHHx) is a thermoplastic biopolyester with a slow crystallization rate. L-Phenylalanine (L-PH) was used to improve the crystallization rate of PHBHHx. The noni- sothermal crystallization kinetics and melting behaviors of PHBHHx and PHBHHx/L-PH samples were characterized and compared with differential scanning calorimetry. At cooling rates of 2, 5, 10, and 208C/min, PHBHHx/L-PH could crystallize at higher temperatures than pure PHBHHx. A modified Avrami equation based analysis showed that the addition of L-PH shortened the half-time of crystallization of PHBHHx from 9.6 to 8.0 min and increased the composite rate constant of PHBHHx from 0.201 to 0.283 during the nonisothermal crystallization process at a cooling rate of 108C/min. For other cooling rates, similar trends of changes were observed. These indicated a faster crystallization rate of PHBHHx in the presence of L-PH. PHBHHx/L-PH samples showed a higher melting temperature and a sharper melting peak than those of the pure PHBHHx, which suggested that L-PH as a nucleation agent improved the perfection of the PHBHHx crystals. Stress-strain measurements showed that both PHBHHx and PHBHHx/L-PH maintained their ductile and elastic properties during the 60 days of the aging study. 2008 Wiley Periodicals, Inc. J Appl Polym Sci 110: 2950-2956, 2008

[1]  Y. Inoue,et al.  Effect of Aging on the Mechanical Properties of Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) , 2007 .

[2]  I. Noda,et al.  Miscibility and crystallization behavior of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) and methoxy poly(ethylene glycol) blends , 2006 .

[3]  Guoqiang Chen,et al.  The application of polyhydroxyalkanoates as tissue engineering materials. , 2005, Biomaterials.

[4]  Y. Inoue,et al.  Nucleation Mechanism of α-Cyclodextrin-Enhanced Crystallization of Some Semicrystalline Aliphatic Polymers , 2005 .

[5]  Y. Inoue,et al.  Effect of lignin particles as a nucleating agent on crystallization of poly(3‐hydroxybutyrate) , 2004 .

[6]  Y. Inoue,et al.  Modal difference in comonomer-unit compositional distributions of poly(3-hydroxybutyrate-co-4-hydroxybutyrate)s biosynthesized by two strains, Ralstonia eutropha and Alcaligenes latus. , 2004, Biomacromolecules.

[7]  Jun Xu,et al.  Direct AFM Observation of Crystal Twisting and Organization in Banded Spherulites of Chiral Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) , 2004 .

[8]  A. E. Dowrey,et al.  Polymer alloys of Nodax copolymers and poly(lactic acid). , 2004, Macromolecular bioscience.

[9]  M. Yasuniwa,et al.  Thermal analysis of the double-melting behavior of poly(L-lactic acid) , 2004 .

[10]  Y. Inoue,et al.  Alpha-cyclodextrin-enhanced crystallization of poly(3-hydroxybutyrate). , 2003, Biomacromolecules.

[11]  X. Sun,et al.  Melting behavior and crystallization kinetics of starch and poly(lactic acid) composites , 2003 .

[12]  A. Tonelli,et al.  Melting and crystallization behaviors of biodegradable polymers enzymatically coalesced from their cyclodextrin inclusion complexes. , 2003, Biomacromolecules.

[13]  Huili Yang,et al.  Effect of nucleating agents on the crystallization of poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) , 2002 .

[14]  P. Hu,et al.  Study on the three-dimensional proliferation of rabbit articular cartilage-derived chondrocytes on polyhydroxyalkanoate scaffolds. , 2002, Biomaterials.

[15]  S. Padgette,et al.  Biosynthesis and properties of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) polymers. , 2002, Biomacromolecules.

[16]  S. Park,et al.  Industrial scale production of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) , 2001, Applied Microbiology and Biotechnology.

[17]  J. Hao,et al.  Miscibility, thermal behaviour, morphology and mechanical properties of binary blends of poly[(R)‐3‐hydroxybutyrate] with poly(γ‐benzyl‐L‐glutamate)+ , 2001 .

[18]  Li-song Dong,et al.  Nonisothermal crystallization and melting behavior of poly(?-hydroxybutyrate)-Poly(vinyl-acetate) blends , 1999 .

[19]  Y. Inoue,et al.  Studies on comonomer compositional distribution of the bacterial poly(3-hydroxybutyric acid-co-3-hydroxypropionic acid)s and crystal and thermal characteristics of their fractionated component copolyesters , 1998 .

[20]  Xiangling Ji,et al.  The double-melting behavior of poly(ether diphenyl ether ketone) , 1997 .

[21]  J. N. Hay,et al.  The physical ageing of amorphous poly(hydroxybutyrate) , 1996 .

[22]  H. Abe,et al.  Microbial synthesis and characterization of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) , 1995 .

[23]  R. Marchessault,et al.  Multiple melting in blends of isotactic and atactic poly(β-hydroxybutyrate) , 1994 .

[24]  R. Marchessault,et al.  Melting and Crystallization in Bacterial Poly(.beta.-hydroxyvalerate),PHV, and Blends with Poly(.beta.-hydroxybutyrate-co-hydroxyvalerate) , 1994 .

[25]  Pj Piet Lemstra,et al.  Crystallization phenomena in bacterial poly[(R)-3-hydroxybutyrate]: 2. Embrittlement and rejuvenation , 1993 .

[26]  Y. Inoue,et al.  Structure and physical properties of bacterially synthesized polyesters , 1992 .

[27]  A. Anderson,et al.  Occurrence, metabolism, metabolic role, and industrial uses of bacterial polyhydroxyalkanoates. , 1990, Microbiological reviews.

[28]  Y. Doi,et al.  New bacterial copolyesters produced in Alcaligenes entrophus from organic acids , 1988 .

[29]  P. Barham,et al.  The relationship between microstructure and mode of fracture in polyhydroxybutyrate , 1986 .

[30]  A. Jeziorny.  Parameters characterizing the kinetics of the non-isothermal crystallization of poly(ethylene terephthalate) determined by d.s.c. , 1978 .

[31]  M. Avrami.  Granulation, Phase Change, and Microstructure Kinetics of Phase Change. III , 1941 .

[32]  M. Avrami.  Kinetics of Phase Change. II Transformation‐Time Relations for Random Distribution of Nuclei , 1940 .

[33]  M. Avrami.  Kinetics of Phase Change. I General Theory , 1939 .