摘要
玻璃化转变温度（Tg）是聚合物重要的特性参数，压缩CO2环境中聚合物的玻璃化转变温度的测定，更是超临界流体技术在聚合物科学领域中成功应用的前提条件。根据蠕变柔量实验原理，自建一套测定高压环境下玻璃化转变温度的实验装置。利用该装置对聚对苯二甲酸乙二醇酯（PET）、聚苯乙烯（PS）、聚氯乙烯（PVC）以及聚甲基丙烯酸甲酯（PMMA）在大气中及压缩CO2环境中的Tg进行了测定。设定实验的平衡吸附温度为室温，平衡吸附压力范围分别为：PET，0～3．5MPa；PS，0～11．0MPa；PVC，0～9．0MPa；PMMA，0～4．5MPa。在大气中测定的结果与文献中的结果相吻合，表明所设计的实验方法及实验装置是可靠并有效的，可用于高压环境下聚合物的玻璃化转变温度的测定。从压缩CO2中的聚合物Tg测定结果可以看出，CO2对聚合物具有较明显的溶胀、增塑作用，可显著降低聚合物的Tg。
Glass transition temperature （Tg） is an important characteristic parameter of polymers. The investigation of polymers＇ Tg in compressed CO2 is especially necessary for the application of supercritical fluids technique in polymer science. In this paper, based on creep compliance experimental principle,an apparatus for testing Tg of polymers in high pressure environment is established. Glass transition temperature of PET,PS,PVC and PMMA in atmosphere and in compressed CO2 has been tested. In the experiment processes, the equilibrium adsorption temperature is room temperature, and the equilibrium adsorption pressure ranges are as following.0～3.5 MPa for PET,0～11.0 MPa for PS, 0～9.0 MPa for PVC and 0～4.5 MPa for PMMA. The Tg obtained in atmosphere using this apparatus agree well with those in literature. This proves that the experimental method and the apparatus developed in this work are reliable and valid,so they can be applied to determine Tg of polymers at high pressure. From the results of Tg of polymers in compressed CO2 ,we can conclude that CO2 has distinct swelling and plasticizing effects on polymers,so that CO2 can make Tg of polymers decrease largely.
出处
《高压物理学报》
EI
CAS
CSCD
北大核心
2006年第3期243-248,共6页
Chinese Journal of High Pressure Physics
基金
国家自然科学基金(20277004)
作者简介
李志义（1959-），男，教授，博士生导师，主要从事超临界流体过程及特殊流动过程研究．E-mail：lizy@dtut．edu．cn.
通讯作者：刘学武（1974），男，讲师，博士，主要从事超临界流体、粉体研究工作．Email：liu_xuewu@21cn．com.
