新型聚醋酸乙烯乳液的改性及合成工艺探讨研究

Study on Modification and Synthesis of a New Type of Polyvinyl Acetate Emulsion

通过丙烯酸改性聚醋酸乙烯乳液,得到适用于高速粘结设备的乳液。采用种子乳液聚合合成工艺,合成聚醋酸乙烯核结构,再将丙烯酸和醋酸乙烯单体接枝到核结构上,形成壳结构,对聚醋酸乙烯进行改性,降低了乳液的最低成膜温度,提高了乳液的粘度,合成了一种新型的白乳胶。对单体的滴加速度、壳结构单体的配料比例、引发剂的加入方式及加入量、保护胶体的种类和用量等因素对乳液性能的影响进行了研究。实验结果表明,当m(AA)∶m(VAC)=3∶10,AA 0.73%(质量分数,下同);引发剂用量0.3%;PVA1788∶PVA1799=1∶2为配方比例,可以得到满足生产需要的乳液;在合成工艺上,采取引发剂加入方式为分步补加,改性单体通过核壳结构对聚醋酸乙烯进行改性。通过配方和合成工艺的研究,本实验得到了能够适用于高速粘结设备的乳液产品。

Polyvinyl acetate emulsion was modified with acrylic acid to obtain the emulsion that can be used in high-speed bonding of equipments. The nuclear structure of polyvinyl acetate was synthesized by seeded emulsion polymerization process, and then acroleic acid and vinyl acetate monomers were grafted on the nuclear structure to form the shell structure. A new type of white latex was obtained by modifying polyvinyl acetate to reduce the minimum film formation temperature of emulsion and increase the viscosity. The influence of monomer adding speed, ratio of monomers, initiator adding way and dosage, protective agent type and dosage on emulsion properties was investigated. The results show that, the optimal reaction conditions are as follows： maa：mvac=3：10, PVA1788：PVA1799=1：2, AA dosage 0.73%,initiator dosage 0.3%.