Abstract:

A waterborne polyacrylate colloid with hard core and soft shell structure was synthesized with methyl methacrylate (MMA), styrene (St), butyl acrylate (BA), methacrylic acid (MAA) as monomers, diacetone acrylamide (DAAM) as crosslinking monomer and adipic acid dihydrazide (ADH) as crosslinking agent. By adjusting the glass transition temperature (T_g), the emulsion can be self?forming film without adding film forming additive at room temperature. The influence of DAAM?ADH crosslinking system on the properties of latex films was investigated. DSC and TGA analysis showed that the T_g and thermal stability of crosslinked latex films are higher than those of uncrosslinked films. When the mass ratio of DAAM in core?shell is 1∶2, the comprehensive performance of latex films is better than that distributed in core or shell alone. With the increase of DAAM content, the water absorption decreased from 18.99% to 4.38%, and the Gel Fraction increased from 79.30% to 90.84%. When the molar ratio of ADH/DAAM is 1.25, the water absorption reaches the lowest and the Gel Fraction reaches the maximum.

Key words: Room temperature self?crosslinking, Zero film forming additive, Waterborne polyacrylate, Ketone hydrazine crosslinking

摘要：

以甲基丙烯酸甲酯（MMA）、苯乙烯（St）、丙烯酸丁酯（BA）、甲基丙烯酸（MAA）为单体，以双丙酮丙烯酰胺（DAAM）为交联单体，以己二酸二酰肼（ADH）为交联剂，合成了具有硬核软壳结构的水性聚丙烯酸酯胶体。通过调节玻璃化转变温度（T_g），使乳液在室温下不添加成膜助剂就可以自成膜。探究了DAAM?ADH交联体系对乳胶膜性能的影响，DSC和TGA分析结果表明交联后乳胶膜的T_g和热稳定性高于未交联的薄膜；当DAAM在核与壳中的质量比为1∶2时，综合性能优于其单独分布在核或壳中；随着DAAM质量分数的增加，吸水率从18.99%降低至4.38%，凝胶分数从79.30%提高至90.84%；当n（ADH）/n（DAAM）为1.25时，吸水率最低，凝胶分数最大。

关键词: 室温自交联, 零成膜助剂, 水性聚丙烯酸酯, 酮肼交联