Synthesis and Thermostability of Crystalline/Amorphous Triblock Copolymers Consisting of PHBV and PMMA
Author(s): Heng-xue Xiang, Shi-chao Wang, Xiao-shuang Wen, Zhe Zhou, Mei-fang Zhu, State Key Lab for Modification of Chemical Fibers & Polymer Material, College of Materials Science and Engineering, Donghua University
Pages: 40-48
Year: 2014 Issue: 1
Journal: Acta Polymerica Sinica
Keyword: Crystalline /amorphous; PHBV; PMMA; Triblock copolymer; Thermodegradation kinetics; ATRP;
Abstract: Crystalline /amorphous triblock copolymers PMMA-b-PHBV-b-PMMA with bacterial polyester poly-( 3-hydroxybutyrate-co-3-hydroxyvalerate)( PHBV) as crystalline component and polymethyl methacrylate( PMMA) as amorphous component were prepared via atom transfer radical polymerization( ATRP). Molecular weight and molecular weight distribution,molecular structure have been characterized by gel permeation chromatography( GPC),together with Fourier transform infrared spectroscopy( FTIR),and1H nuclear magnetic resonance(1H-NMR). The morphology of the triblock copolymers was characterized by polarizing optical microscopy( POM). Thermal stabilities have been studied by thermal gravimetric method( TG),and the degradation activation energy was calculated by Horowitz-Metzger method. Results showed that the maximum yield of triblock copolymer was 92. 39%. The crystalline morphology of neat PHBV shows obvious banded spherulites. With PMMA content increase,the crystalline morphology of triblock copolymers changes from "banded pattern"to "radial pattern",with a decreasing radius of spherulites. When the molar ratios of PMMA and PHBV is 10 ∶ 1,the edge of spherulites becomes unclear. The TG analysis revealed that T0,T5%,T max of triblock copolymer with the molar ratios of PMMA and PHBV between 2∶ 1 and 8∶ 1 were raised to 25,15 and 40 ℃,and the degradation activation energy of triblock copolymers may decrease from 428. 25 kJ·mol-1to 169. 83 kJ·mol-1.
Pages: 40-48
Year: 2014 Issue: 1
Journal: Acta Polymerica Sinica
Keyword: Crystalline /amorphous; PHBV; PMMA; Triblock copolymer; Thermodegradation kinetics; ATRP;
Abstract: Crystalline /amorphous triblock copolymers PMMA-b-PHBV-b-PMMA with bacterial polyester poly-( 3-hydroxybutyrate-co-3-hydroxyvalerate)( PHBV) as crystalline component and polymethyl methacrylate( PMMA) as amorphous component were prepared via atom transfer radical polymerization( ATRP). Molecular weight and molecular weight distribution,molecular structure have been characterized by gel permeation chromatography( GPC),together with Fourier transform infrared spectroscopy( FTIR),and1H nuclear magnetic resonance(1H-NMR). The morphology of the triblock copolymers was characterized by polarizing optical microscopy( POM). Thermal stabilities have been studied by thermal gravimetric method( TG),and the degradation activation energy was calculated by Horowitz-Metzger method. Results showed that the maximum yield of triblock copolymer was 92. 39%. The crystalline morphology of neat PHBV shows obvious banded spherulites. With PMMA content increase,the crystalline morphology of triblock copolymers changes from "banded pattern"to "radial pattern",with a decreasing radius of spherulites. When the molar ratios of PMMA and PHBV is 10 ∶ 1,the edge of spherulites becomes unclear. The TG analysis revealed that T0,T5%,T max of triblock copolymer with the molar ratios of PMMA and PHBV between 2∶ 1 and 8∶ 1 were raised to 25,15 and 40 ℃,and the degradation activation energy of triblock copolymers may decrease from 428. 25 kJ·mol-1to 169. 83 kJ·mol-1.
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