Study on foam formation mechanism and application performance of pressure sensitive adhesive emulsion
Acrylic emulsion with different emulsifier dosages was prepared.The synthesis process of acrylic emulsion formula and the mechanism of foam formation were analyzed.The influence of emulsifier dosage,emulsion surface tension,emulsion solid content and defoamer on the foam and application performance of pressure sensitive adhesive emulsion was discussed.It was clear that the main reasons for foam formation were the high foaming rate of emulsifier,the high surface tension of foam,the high rotational viscosity because of high solid content of emulsion,and the selection and amount of defoamer.The research results showed that,(1)The emulsifier dosage not only had a great impact on the weather resistance of pressure sensitive adhesive and the stability of emulsion polymerization,but also had a great impact on the foam formation.Taking all factors into consideration,it was advisable to control the dosage of emulsifier at 0.50％.(2)The control of surface tension in the pressure sensitive adhesive emulsion system was directly related to the change of foam surface tension,and the emulsion surface tension should be controlled within the range of 38-40 mN/m.(3)The solid content of pressure sensitive adhesive emulsion had a direct impact on the rotational viscosity of emulsion and foam content,and also had a crucial impact on the application performance of emulsion.(4)Adding an appropriate amount of defoamer was the best scheme to improve the defoaming ability of pressure sensitive adhesive emulsion,and the application conditions were convenient.Different systems of defoamers had good effects on the elimination of foam.Mineral oil defoamer-A and polyether defoamer-C could provide good defoaming performance,weather resistance and film forming performance when the mass fraction was 0.05％,and their comprehensive application effect was better than other systems of defoamers.(5)The addition mode of defoamer could affect the dispersion performance of defoamer.The emulsification dispersion mode of emulsion could improve the dispersion of defoamer,reduce the foam of emulsion,and improve the film forming performance of emulsion.
万方数据
维普
