碱溶胀缔合型增稠剂及其流变行为影响因素分析

Overview of Hydrophobically-Modified Alkali-Swellable Emulsion Thickener and Analysis of Factors Affecting Its Rheological Behavior

碱溶胀缔合型增稠剂(HASE)是一类常用于水性涂料的通用流变助剂。它一般是由甲基丙烯酸(MAA)、丙烯酸乙酯(EA)、疏水缔合单体(HAM)通过乳液共聚制得。HASE黏度大小及其流变行为受诸多因素影响。本文主要研究了影响HASE流变行为的几个因素,包括共聚物酸含量、单体种类及配伍、共聚物相对分子质量、疏水缔合单体的种类与结构(包括乙氧基链的长度、端基烷基链段的长度),以及HASE应用体系内介质(离子浓度、表面活性剂的种类与含量、PH及中和用碱的种类)。明确了不同流变性能要求下,HASE结构设计的要求。

The hydrophobically-modified alkali-swellable emulsion(HASE)thickener is a kind of rheological additives commonly used in waterborne coatings.It consists of a copolymer of methacrylic acid(M A A),ethyl acrylate(EA)and hydrophobically-modified associative monomer(HAM).The viscosity and rheological behavior of HASE are affected by various factors.In this paper,several factors that affected the rheological behavior were analyzed and discussed,including the acid content of copolymer,types and ratio of monomers,the molecular weight of copolymer,the types and structures of hydrophobically-modified associative monomer(HAM)(including the length of ethoxyl chain and end alkyl chain)and the medium in which HASE was used(including ion concentration,type and content of surfactants,pH value and neutralizing alkali).The requirements of HASE structure design with different rheological properties was confirmed.