不同交联层厚度的聚丙烯酸酯乳液的制备及压敏性能

Preparation and Properties of Polyacrylic Pressure-Sensitive Adhesives with Different Crosslinking Layer Thicknesses

通过调控增长阶段交联剂参与反应的时间,采用半连续种子乳液聚合方法制备了一系列固含量为50%,乳胶粒粒径相同但交联层厚度不同的聚丙烯酸酯乳液。采用动态光散射、凝胶渗透色谱和动态力学热分析等手段,考察了交联层厚度对乳液聚合过程、聚合物分子结构及分子运动的影响。结果表明,交联层厚度对聚合过程和乳液稳定性没有明显影响;随着交联层厚度的增加,聚合物的凝胶含量和储能模量增加,可溶部分相对分子质量和缠结相对分子质量减小。依据FINAT标准测试了该乳液压敏胶的初黏力、剥离力和耐持黏性。控制交联层厚度在合适范围,可得到压敏性能均衡的乳液。

By regulating the feed time of the crosslinking agent in the growth stage,a series of poly(butyl acrylate)/poly(butyl acrylate-co-methacrylic acid-co-1,4-butanediol dimethacrylate)(PBMBD)latexes with the same particle size and different crosslinking layer thicknesses were synthesized at a solid content of 50%via semi-continuous emulsion polymerization.The effects of crosslinking layer thickness on emulsion polymerization,molecular structure,and molecular motion were investigated by dynamic light scattering(DLS),gel permeation chromatography(GPC)and dynamic mechanical thermal analysis(DMA).The results show that the crosslinking layer thickness has no significant effect on the polymerization process and emulsion stability.With the increase of the crosslinking layer thickness,the gel content and storage modulus of the polymer increase,while the molecular weight of the soluble polymer and entanglement molecular weight decrease.According to FINAT test methods,the tack force,peel force and shear resistance of the emulsion were evaluated.The emulsion with balanced pressure-sensitive properties can be obtained by controlling the crosslinking layer thickness in an appropriate range.