MAA-AMPS-HEMA-MA共聚物浆钙分散剂的合成与表征

Synthesis and Application of Quadripolymer Dispersant of Methacrylic Acid-2-Acrylamide-2-Methylcsulfonic Acid-Hydroxyethyl Methacrylate-Maleic Anhydride

以甲基丙烯酸(MAA)、2-丙烯酰胺-2-甲基丙磺酸(AMPS)、甲基丙烯酸羟乙酯(HEMA)以及马来酸酐(MA)为单体,采用反应活性较低的衣康酸(IA)作为分子量调节剂,共聚得到MAA-AMPS-HEMA-MA四元聚合物,再将共聚物与碳酸钙包覆剂硬脂酸钠进行复配得到复配分散剂。以四元聚合物合成工艺作为研究对象,考察了单体比例和IA浓度对四元聚合物分子量的影响;再以复配分散剂应用性能作为研究对象,用Brookkfield DV-Ⅱ+可编程黏度计和扫描电镜等仪器测定不同分子量的复配分散剂对造纸涂料碳酸钙的分散性能的影响,对分散后颗粒表面形态进行表征。结果表明,单体摩尔配比(MAA:AMPS:HEMA:MA)为4:1:1:1、IA:MAA为2:8,聚合物与硬脂酸钠按质量比5:1进行复配,所得到的复配分散剂对碳酸钙分散效果较好。复配分散剂的最佳用量为0.8%,此时浆钙分散体系黏度降至68.4mPa s(未加分散剂的浆钙黏度412.4 mPa s)。

The quadripolymer dispersants were synthesized with methacrylic acid （MAA）, maleic anhydride （MA）, 2-acrylamide-2-methylcsulfonic acid （AMPS） and hydroxyethyl methacrylate （HEMA） as monomers, itaconic acid （IA） as molecular weight regulator, which were then composited with sodium stearate. The influences of monomer ratio, temperature, initiator concentration and IA concentration on the molecular weight of the synthesized quadripolymer dispersants were studied firstly. Then the dispersant capacities of the quadripolymers and their mixtures with sodium stearate were characterized by Brookfield rotary viscometer and scanning electron microscope. The experiment results show that the mixture with polymer/sodium stearate mass ratio of 5/1 and the polymer prepared with molar ratio of the monomers MMA：AMPS：HEMA：MA=4：1：1：1 and W（IA）/W（MMA）=2：8 exhibits good dispersive performance for the dispersal of calcium carbonate system, its suitable used amount is 0.8%（w/w）, and the viscosity of the calcium carbonate system could be decreased from 412.4 mPa.s to 68.4 mPa.s