文献类型：期刊文献

英文题名：Effects of cross-linking by MgCl2 as an initiator on the properties of EVOH

作者：Wang, Bin[1];Lu, Chong[1];Hu, Jing[1];Lu, Weixin[1]

机构：[1]East China Univ Sci & Technol, Sch Mat Sci & Engn, Shanghai 200237, Peoples R China

年份：2022

卷号：35

期号：5

起止页码：665

外文期刊名：JOURNAL OF THERMOPLASTIC COMPOSITE MATERIALS

收录：;EI(收录号：20201308353829);WOS:【SCI-EXPANDED(收录号:WOS:000523878800001)】；

语种：英文

外文关键词：EVOH; MgCl2; cross-linking; mechanical properties

摘要：Ethylene vinyl alcohol (EVOH) with excellent barrier properties has insufficient thermomechanical properties. The introduction of magnesium chloride (MgCl2) as an initiator in EVOH blends improved its properties by cross-linking. Torque behavior and gel experiment analysis indicated that a cross-linking in EVOH was formed. The cross-linking mechanism was confirmed through C-13 nuclear magnetic resonance spectroscopy (C-13 NMR) and Fourier-transform infrared (FTIR) spectrometry. In C-13 NMR spectra, the splitting peaks of CH carbon and CH2 carbon tended to disappear, and the stretching vibration peak of -C=C- was observed in the FTIR spectra. The formation of hydrogen bond between MgCl2 and EVOH destroyed the intramolecular and intermolecular hydrogen bonds of EVOH, which contributed to the dehydration of -OH to form -C=C-, and -C=C- was the basis for a cross-linking reaction. The thermal analysis of blends demonstrated that the melting temperature and crystallization temperature decreased, and the crystallinity gradually disappeared when the MgCl2 content increased. Glass transition temperature significantly increased as the intermolecular force enhanced. Thermogravimetric analysis showed that a cross-linked structure could improve the thermostability of EVOH with an increase in the MgCl2 content. Mechanical test results revealed a remarkable increase in the tensile strength of EVOH as the MgCl2 content increased.