锂电黏接剂用聚偏氟乙烯溶液的流变性质及分析方法研究  

Study on the Rheological Properties and Analytical Methods of Polyvinylidene Fluoride Solutions for Lithium Electric Adhesives

作　　者：吴旭晴[1] 吴于松[1] 欧阳希凯 邹丁艳[1] 邵丽萍 许远远[1] WU Xuqing;WU Yusong;OUYANG Xikai;ZOU Dingyan;SHAO Liping;XU Yuanyuan(Sinochem Lantian Co.,Ltd.,Zhejiang Research Institute of Chemical Industry Co.,Ltd.,Hangzhou 310023,China)

机构地区：[1]中化蓝天集团有限公司,浙江省化工研究院有限公司,浙江杭州310023

出　　处：《塑料工业》2024年第11期94-99,共6页China Plastics Industry

摘　　要：锂电黏接剂用聚偏氟乙烯(PVDF)的相对分子质量比较高,根据聚合工艺可将其划分为两类,乳液法PVDF与悬浮法PVDF,两种PVDF的分子结构差异很大,导致其流变性质相差较大。本文通过使用凝胶渗透色谱仪、差示扫描量热仪、核磁共振波谱仪和旋转流变仪,系统研究了乳液法和悬浮法PVDF的分子结构与流变性质。结果表明,乳液聚合PVDF存在一定量的微凝胶和少量的支化结构,悬浮聚合PVDF为长直链结构,悬浮聚合PVDF具有更高的熔点和结晶度。两种PVDF溶液的流变性质差异较大,乳液聚合PVDF在低剪切速率区黏度较高,剪切变稀的临界剪切速率偏低;悬浮聚合PVDF在低剪切速率时,表现为第一牛顿区,临界剪切速率高。此外,通过研究PVDF溶液流变性质与其相对分子质量的关系,得到长直链PVDF溶液零剪切黏度与重均分子量之间的关系。该关系的建立使悬浮法PVDF通过流变测试计算得到重均分子量成为可行的分析方法。The relative molecular mass of polyvinylidene fluoride(PVDF)used for lithium electric adhesives is relatively high.According to the polymerization technique,PVDF could be divided into two categories,emulsion-polymerized PVDF and suspension-polymerized PVDF.Due to the structure differences,the rheological properties of the two PVDFs are unlike.In this paper,the molecular structures and rheological properties of PVDFs produced by the emulsion and suspension methods were systematically studied by using gel permeation chromatograph,differential scanning calorimeter,nuclear magnetic resonance spectrometer and rotary rheometer.The results show that there are some microgels and a few branched structures in emulsion-polymerized PVDF.The suspension-polymerized PVDF has long straight chain structures,a higher melting point,and a higher crystallinity.The rheological properties of the two PVDF solutions are very different.The viscosity of emulsion-polymerized PVDF is relatively high at low shear rate,the critical shear rate of shear thinning is lower.The suspension-polymerized PVDF shows the first Newtonian region at low shear rate and has a high critical shear rate.Besides,through investigating the relationships between the PVDF solution rheological properties and the relative molecular mass,the relationships between the zero shear viscosity of long straight chain PVDF solution and the weight-average molecular weight are obtained.The established relationship makes it feasible to calculate the PVDF weight-average molecular weight by the rheological method.

关 键 词：聚偏氟乙烯 聚合物流变性质 零剪切黏度 重均分子量 

分 类 号：TQ325.4[化学工程—合成树脂塑料工业]