EG-SCCO_2-PET三元体系相平衡  

Phase equilibrium of EG-SCCO_2-PET ternary system

作　　者：蒋春跃[1] 王秀祥[1] 孙志娟[2] 张玉[2] 

机构地区：[1]浙江工业大学化学工程学院,浙江杭州310014 [2]浙江工业大学海洋学院,浙江杭州310014

出　　处：《化学工程》2017年第6期27-31,共5页Chemical Engineering(China)

基　　金：国家自然科学青年基金资助项目(21104066);浙江省自然科学基金资助项目(LY15B060006)

摘　　要：利用超临界二氧化碳(SCCO_2)来辅助聚合物系脱挥可有效降低聚合物中挥发物含量,从而有利于改善聚合物的性能,且SCCO_2易与体系分离,可避免传统脱挥方式带来的问题。SCCO_2相平衡的分配参数是研究聚合物分离体系的基础,用实验方法获得分配系数对于指导SCCO_2来辅助聚合物系脱挥具有重要的意义。文中采用静态法研究了乙二醇(EG)-超临界二氧化碳(SCCO_2)-聚对苯二甲酸乙二醇酯(PET)三元体系相平衡,并探究了温度和压力对相平衡的影响。在温度为323.15—363.15 K,压力为9—17 MPa范围内,测得PET样品中EG在SCCO_2中的溶解度为0.392—1.13 g/L,并进一步计算得到EG在SCCO_2相与PET相间的分配系数为0.070 8—0.419 7,结果表明在合适的温度及高压下,SCCO_2可有效脱除PET中的挥分。Supercritical Carbon Dioxide （SCCO2 ） was used to remove volatile in the process of solid phase polycondensation, which improved properties of the obtained polymer. Moreover, it was easy to separate SCCO2 from the polymerization system, so some problems caused by traditional separation way could avoid. Distribution coefficients of phase equilibrium was the seperation basis of the polymerization system with SCCO2. Thus, it was very important to obtain the distribution coefficients by experimental method for removing volatile with SCCO2 in the process of solid phase polycondensation. Ternary phase equilibrium of ethylene glycol （EG） -supercritical carbon dioxide（ SCCO2 ）-polyethylene terephthalate（PET） was investigated by the static method. Moreover, the effects of temperature（323.15-363.15 K） and pressure （9-17 MPa） on the phase equilibrium were analyzed in detail. The results show that the solubility of EG in SCCO2 for PET sample is 0. 392-1. 13 g/L in this system, and the distribution coefficients of EG between the SCCO2 and PET phases calculated is 0. 070 8-0. 419 7, which indicates that the volatile in PET can be removed effectively at specific temperature and high pressure.

关 键 词：脱挥 静态法 聚对苯二甲酸乙二醇酯 相平衡 分配系数 

分 类 号：TQ013.1[化学工程]