文献类型：期刊文献

英文题名：Chain flexibility characterization of poly(oxymethylene)

作者：Xu, ZD; Su, CW; Li, D; Huang, Y; Mays, JW

机构：[1]E China Univ Sci & Technol, Inst Polymer Sci & Engn, Shanghai 200237, Peoples R China;[2]Univ Alabama, Dept Chem, Birmingham, AL 35294 USA

年份：1998

卷号：4

期号：5

起止页码：471

外文期刊名：INTERNATIONAL JOURNAL OF POLYMER ANALYSIS AND CHARACTERIZATION

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000077812600006)】；

语种：英文

外文关键词：poly(oxymethylene); characteristic ratio C-infinity; chain flexibility; dilute solution viscosity; MHS equation

摘要：Flory's characteristic ratio C-infinity for poly(oxymethylene) (POM) has been measured by Stockmayer from viscosity measurements in hexafluoroacetone sesquihydrate. The value of C-infinity determined was 10.5, almost the same as that for polystyrene. This C-infinity value was suspected of being higher than the real C-infinity value of POM because of the strong solvation power of hexafluoroacetone hydrate and its specific interaction with POM. In this paper, the C-infinity of POM were determined in m-cresol at 100 degrees C and p-chlorophenol at 60 degrees C via intrinsic viscosity measurements. Characteristic ratios of 6.72 and 6.97 were found at 60 degrees C and 100 degrees C, respectively. The results show that the POM chain is more flexible than polystyrene and is similar in flexibility to polyethylene chain. The positive temperature coefficient of chain dimensions indicates that more compact chain conformations have lower energies. The Mark-Houwink-Sakurada equations for POM in m-cresol (100 degrees C) and p-chlorophenol (60 degrees C) have been evaluated simultaneously.