一种高强度双组分拼板胶PVAc乳液的制备

以聚乙烯醇为保护胶,配合乳化剂,将混合单体采用半连续乳液聚合法滴加制备一种高强度双组分拼板胶用聚醋酸乙烯酯(PVAc)乳液。研究了pH缓冲剂、聚乙烯醇、主单体和功能单体的种类及用量对乳液稳定性和耐水性等的影响。结果表明,NaHCO_3可保乳液聚合反应平稳,提高单体转化率和贮存稳定性;疏水型软单体叔碳酸乙烯酯的引入,可以有效地改善胶膜的柔韧性并提高乳液的固化速度、耐水性;适量甲基丙烯酸甲酯可明显降黏并改善乳液的施工便捷性;甲基丙烯酸和羟乙基丙稀酸酯的引入,可以改善乳液冻融稳定性和耐水强度的同时,还能调节拼板胶的使用期。

Preparation of PVAc Emulsion as Two-component Plate Alignment Adhesive With High Strength

Poly(vinyl acetate) (PVAc) emulsion as a kind of two-component plate alignment adhesive with really high shear strength,was prepared by semi-continuous emulsion polymerization,which was composed of polyvinyl alcohol (PVA) as protective colloid,emulsifier and the mixed monomer.The effect of varieties and amounts of pH buffer solution,PVA,main monomers and functional monomers on the stability of emulsion and water resistance was investigated.The results showed that NaHCO3 could optimize the polymerization stability,storage stability and conversion rate;Hydrophobic soft monomer Veova-10 could improve the flexibility of the film,accelerate the drying speed and enhance resistance to water.Methyl methacrylate could help the application more convenient by reducing viscosity.Methyl acrylate acid and hydroxyethyl acrylate could improve the freeze-thaw stability and water-resistance strength,as well as working life.