PVC及PMMA在CO_2环境中玻璃化转变特性的研究

对聚合物在CO2环境中的玻璃化转变特性进行了研究。利用蠕变柔量法,在自建的实验装置上,对聚氯乙烯和聚甲基丙烯酸甲酯在CO2环境中不同压力下的玻璃化转变温度进行了测定,并利用间接法测定了对应状态下聚合物中CO2的质量分数。结果表明,在CO2环境中2种材料的玻璃化转变温度显著降低。利用基于经典热力学与统计热力学理论构建的模型,对聚合物中不同的CO2质量分数对应的玻璃化转变温度值进行了计算,得到的计算结果与实验结果较吻合。

Research on characteristic of PVC and PMMA glass transition in CO2

Glass transition temperature(T_g) is an important characteristic parameter,which indicates the plasticity of polymers.In order to make an effective research on the glass transition characters,the T_g of PVC and PMMA in CO_2 at different pressure is tested by the application of creep compliance on the self-established experimental device and the content of CO_2 in the corresponding state is determined by using indirect testing method.The result proves that the T_g of the two materials in CO_2 decreases greatly.The calculation results of T_g with different CO_2 content by using the theoretical model,which is based on classical and statistical thermodynamics agrees well with the experimental result.