加工温度与助剂对聚碳酸亚丙酯热降解性影响

摘要

通过特性黏度法研究加工温度与助剂对聚碳酸亚丙酯(PPC)热降解性的影响,并采用凝胶渗透色谱法评价特性黏度法结果的可靠性.结果表明:PPC对温度敏感,温度升高,特性黏度变低,相对分子质量变低.当加工温度从120℃升高到160℃,PPC的特性黏度从2.16 dL/g下降到1.31 dL/g,继续升高到200℃时,特性黏度从1.31dL/g下降到1.18 dL/g,说明温度越高,PPC特性黏度越低,热降解加剧,在120-160℃下降解速率较在160-200℃下快.在加工温度为140℃时,PPC的特性黏度为1.62 dL/g,PPC/MAH和PPC/AO1010的特性黏度比PPC的特性黏度分别提高了0.65 dL/g和0.25 dL/g,说明封端剂MAH、热稳定剂AO1010的加入能抑制PPC的热降解,提高PPC的热稳定性.采用特性黏度法研究PPC热降解的方法是可行的,且经济、方便、快捷,是研究PPC热降解性、可实现在线分析的一种良好方法.%The effect of processing temperature and additives on the thermal degradation of poly propylene carbonate (PPC) was researched by intrinsic viscosity method, and the reliability of result was analyzed by GPC ( gel permeation chromatography). The results show that PPC is sensitive to temperature. With the temperature increase, the intrinsic viscosity and the relative molecular mass of PPC become lower. The temperature increases from 120 ℃ to 160 ℃ ,the intrinsic viscosity of PPC decreases from 2. 16 dL/g to 1. 31 dL/g. The temperature increases from 160 ℃ to 200 ℃ , the intrinsic viscosity of PPC decreases from 1. 31 dL/g to 1. 18 dL/g. It indicates that the intrinsic viscosity of PPC becomes lower and the thermal degradation becomes faster with the temperature increase, and the degradation rate is faster at 120-160℃ than that at 160-200 ℃. The intrinsic viscosity of PPC is 1.62 dL/ g at the processing temperature of 140 ℃ , and that of PPC/MAH and PPC/AO1010 increases by 0. 65 dL/g and 0. 25 dL/g than PPC, respectively. The thermal stability of PPC can be improved in the processing by adding the capping agents MAH and antioxidant AO1010. The study on the thermal degradation of PPC by intrinsic viscosity method is feasible. It is economic, convenient, quick, and a good method of on-line analysis.