铸膜液熟化时间对制备PVDF微孔膜结构与结晶的影响  

Effect of Maturation Time of Dopes on the Morphology and Crystallization of PVDF Membranes

作　　者：王许云[1,2] 张林[1] 陈欢林[1] 周志军[1] 

机构地区：[1]浙江大学材化学院,浙江杭州310027 [2]青岛科技大学化工学院,山东青岛266042

出　　处：《高分子材料科学与工程》2009年第7期57-60,共4页Polymer Materials Science & Engineering

基　　金：国家973计划项目(2003CB615706)

摘　　要：铸膜液的熟化时间对膜内部微观孔结构具有较大影响。当天配制的铸膜液制膜过程中首先发生瞬时液-液分相,稀聚合物相成核,所成膜内部形成有指状大孔的胞腔状结构。经一定熟化时间的铸膜液,熟化过程中内部首先发生固-液微相分离。制膜过程中,铸膜液内微液相区发生液-液相分离,微晶固相区凝胶固化,形成网络状结构。当天配制的铸膜液制得的PVDF膜,主要为β型结晶结构。随着铸膜液熟化时间延长,所制得膜β型结晶所占比例减少,α型结晶所占比例增多。PVDF membranes were prepared by immersion precipitation method. The effects of the maturation time of the dopes on the morphology and crystallization of prepared membranes were examined. For the dope prepared in the initial day, liquid-liquid demixing is ahead of the solid-liquid demixing in the process of the membrane formation. In the maturation process, solid-liquid micro-phase separation occurs first in the system, which results in the existence of the micro-liquid phase and micro-solid phase crystallite area in the dopes. In the process of the membrane formation, liquid-liquid demixing takes place by nucleation and growth of droplets of the polymer rich phase in the micro-liquid phase, and the micro-solid phase crystallites are connected by the polymer chains together forming a three dimensional network gelation morphology. With the maturation time lasting of the dopes, the proportion of ＂β＂ crystallite is decrease, but that of ＂α＂ crystallite increase for the prepared PVDF membranes.

关 键 词：聚偏二氟乙烯(PVDF) 相转化 熟化时间 成膜机理 结晶 

分 类 号：TB383[一般工业技术—材料科学与工程]