Metastable polymer blends by precipitation with a compressed fluid antisolvent

被引：33

作者：

Mawson, S ^{[1
]}

Kanakia, S ^{[1
]}

Johnston, KP ^{[1
]}

机构：

[1] UNIV TEXAS, DEPT CHEM ENGN, AUSTIN, TX 78712 USA

来源：

POLYMER | 1997年 / 38卷 / 12期

基金：

美国国家科学基金会;

关键词：

metastable polymer blend; compressed fluid; phase separation;

D O I：

10.1016/S0032-3861(96)00852-X

中图分类号：

O63 [高分子化学（高聚物）];

学科分类号：

070305 ; 080501 ; 081704 ;

摘要：

Metastable polymer blends of polycarbonate (PC) and poly(styrene-co-acrylonitrile) (SAN) are formed by spraying polymer solutions into liquid and supercritical fluid CO2. Because of the rapid mass transfer between the CO2-phase and the solution phase, the blends are trapped in a metastable state before they can phase separate. A transition from a metastable blend with a single glass transition temperature, T-g in the form of particles, to a phase-separated 100 mu m fibre is observed with an increase in polymer concentration from 3.0 to 9.0wt%. This transition is related to the calculated concentration for the dilute to semi-dilute transition, C*, of PC/SAN in THF and the characteristic times for polymer-polymer and polymer-solvent phase separation. PC and SAN do not form a blend at 35 degrees C because of plasticization by CO2. They also do not form a metastable blend when 1.0mm droplets are precipitated into a liquid antisolvent, heptane. (C) 1997 Elsevier Science Ltd.

引用

页码：2957 / 2967

页数：11

共 43 条

[1] CRYSTALLIZATION OF BISPHENOL A POLYCARBONATE INDUCED BY SUPERCRITICAL CARBON-DIOXIDE [J].