转矩流变仪研究羧酸对聚乳酸热稳定性的影响  

Study of the Influence of Carboxylic Acids on the Thermal Stability of Polylactide Acid by Torque Rheometer

作　　者：梅常春[1] 桂宗彦[1] 陆冲[1] 陈其祥[1] 程树军[1] 

机构地区：[1]华东理工大学材料科学与工程学院超细材料制备与应用教育部重点实验室,上海200237

出　　处：《塑料工业》2010年第12期52-55,共4页China Plastics Industry

摘　　要：通过建立模型,计算流动活化能(Ef)和降解速率常数(K),用转矩流变仪研究了癸酸、十二酸和十六酸对聚乳酸(PLA)热稳定性的影响。结果表明:羧酸的加入降低了聚乳酸的热稳定性。随着羧酸主链碳原子数增加,羧酸对聚乳酸的热稳定性影响呈逐渐降低的趋势;羧酸的摩尔分数从0%增至1.00%时,PLA/羧酸体系的熔体黏度从238.4 Pa.s下降至142.1 Pa.s,Ef从70.28 kJ/mol增至159.04 kJ/mol,K从0.72×10-3m in-1增至3.46×10-3m in-1。Thermal stability of polylactide acid （PLA） in the presence of the additive caprie acid, lauric acid and palmitelaidic acid was studied by torque-rheometer combined with the establishment of a model, to calculate the activation energy （Ef） as well as degradation rate constants （K）. The results showed that the carboxylic acid decreased the thermal stability of PLA. As the number of carbon atom on main chain increased, influence of the carboxylic acid on thermal-stability of PLA decreased gradually. Moreover, when the additive molar fraction of carboxylic acid increased from 0% to 1.00%, the melt viscosity decreased from 238.4 Pa · s to 142. 1 Pa · s, and Ef increased from 70.28 kJ/mol to 159. 04 kJ/mol while K increased from 0. 72×10^-3min ^-1 to 3.46 ×10^-3min^ -1, respectively.

关 键 词：聚乳酸 转矩流变仪 热稳定性 流动活化能 降解速率常数 

分 类 号：TQ321.2[化学工程—合成树脂塑料工业]