文献类型：期刊文献

英文题名：Influence of post-treatments of porous poly(vinyl alcohl) membranes

作者：Wang, Yan-Li[1];Yang, Hu[1];Xu, Zhen-Liang[1]

机构：[1]E China Univ Sci & Technol, Chem Engn Res Ctr, Shanghai 200237, Peoples R China

年份：2008

卷号：107

期号：3

起止页码：1423

外文期刊名：JOURNAL OF APPLIED POLYMER SCIENCE

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000251769700008)】；

语种：英文

外文关键词：mechanical properties; membranes; morphology; poly(vinyl ethers)

摘要：Porous poly(vinyl alcohol) (PVA) membranes were prepared by a phase-inversion method. The influence of chemical crosslinking and heat treatments on the swelling degree, resistance to compaction, mechanical strength, and morphology of porous PVA membranes was extensively studied. The crosslinking degree and crystallinity of the membranes, calculated from IR spectra, increased with the treatment time. The porosity, calculated on the basis of swelling experiments, showed a decreasing trend for heat-treated membranes but remained almost at a constant value for crosslinked membranes. Such a change was further proved with scanning electron microscopy pictures. The behavior was explained by the rearrangement of PVA chains during the heat-treatment process, which led to morphological changes in the membranes. The mechanical properties of the porous membranes in dry and wet states were measured, and a great difference was observed between crosslinked and heat-treated membranes in the dry and wet states. The crosslinked membranes showed good mechanical properties in the dry state but became fragile in the wet state. On the contrary, the heat-treated membranes were more flexible in the wet state than in the dry state. This change was explained by the turnaround of inner stress in the systems during the swelling process. (c) 2007 Wiley Periodicals, Inc.