交联剂含量对憎水改性缔合型增稠剂性能的影响

以甲基丙烯酸、丙烯酸乙酯和功能单体二十二烷基聚氧乙烯醚甲基丙烯酸酯为原料,过硫酸铵为引发剂,变化交联剂邻苯二甲酸二烯丙酯(DAP)的量,采用半连续乳液聚合方法合成了DAP含量不同的憎水改性缔合型增稠剂乳液.测定了乳液的黏度和乳胶粒粒径及其分布等性能.考察了乳液运动黏度和透光率随pH的变化.随着pH值的增加,乳液的透光率...

IMPACT OF CROSS-LINKER AMOUNT ON THICKENING PERFORMANCE IN ASSOCIATIVE LATEX THICKENERS

Through semi-batch emulsion polymerization,hydrophobically modified associative thickener latexes were prepared using methacrylic acid and ethyl acrylate as the main monomers,behenyl polyethoxylate ether methacrylate as the functional monomer and dially phthalate(DAP) as the crosslinking agent.Ammonium persulfate was used as the initiator.Properties of the thickener latexes prepared with different amount of DAP,including viscosity,particle size and size distribution,were determined.Evolutions of the viscosity and light transmittance with increasing pH in the thickener latexes were followed.With pH starting from 6.0,light transmittance of the thickener latexes sharply increased,reached a maximal value at pH around 8.1,it remained relatively constant with continuing pH increase.As to the viscosity,a significant increase was also observed at the same time with the light transmittance,followed by a slow decline afterwards.It was found that the properties of the thickener latexes were closely related to the DAP amount used in their preparation.Thickening performance and shearing resistance of the associative thickeners were enhanced when thickener polymers were slightly crosslinked with a low amount of DAP;A too large amount of DAP led to deteriorated swelling and dissolution for the latex particles under alkaline condition,reducing therefore the thickening performance of the thickener.The results were fully interpreted and the thickening mechanism was discussed.