摘要
以生物质聚酯聚(3-羟基丁酸酯-co-3-羟基戊酸酯)(PHBV)为结晶组分、聚甲基丙烯酸甲酯(PMMA)为无定形组分,通过原子转移自由基聚合法(ATRP)制备了ABA型结晶/无定形三嵌段共聚物.采用凝胶色谱法(GPC)、傅里叶红外光谱(FTIR)和核磁共振氢谱(1H-NMR)表征了三嵌段共聚物的分子量及其分子量分布和化学结构;使用热失重分析仪(TG)测试了三嵌段共聚物的热稳定性,并通过Horowitz-Metzger法计算了嵌段共聚物的降解表观活化能.研究表明,三嵌段共聚物的最大转化产率为92.39%;当单体与大分子引发剂的比例为8∶1时,三嵌段共聚物的T0、T5%、T max温度分别提高25 K、15 K和40 K,三嵌段共聚物降解表观活化能E a可由纯PHBV的428.25 kJ·mol-1降低至169.83 kJ·mol-1.
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）, and 1H nuclear magnetic resonance （IH-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 tribloek 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% , Tmax 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-1 to 169.83 kJ·mo1-1.
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
2014年第1期40-48,共9页
Acta Polymerica Sinica
基金
国家杰出青年科学基金(基金号50925312)
长江学者和创新团队发展计划(项目号T2011079
IRT1221)
高等学校博士点基金(基金号20100075110007)
上海市自然科学基金(基金号13ZR1401700)
中央高校基本科研业务费专项基金(基金号CUSF-DH-D-2013007)资助项目
