Preparation and properties of acrylate prepolymer and its pressure sensitive adhesive
Acrylate polymer was synthesized through free radical polymerization using methyl methacrylate(MMA),isooctyl acrylate(2-EHA),acrylic acid(AA),and hydroxyethyl acrylate(HEA)as comonomers,azobisisobutyronitrile(AIBN)as initiator,and ethyl acetate(EA)as solvent.Then,acrylate prepolymer was systhesized by grafting isocyanate ethyl acrylate(AOI)monomer,which was used to prepare UV curable pressure sensitive adhesive(PSA).The effects of structural properties and reaction temperature on the relative molecular weight and distribution of prepolymers,as well as low dosages of functional monomer AA and crosslinking monomer AOI,and weight average molecular weight(Mw)on PSA performance were investigated.The research results showed that,(1)Infrared spectroscopy analysis showed that almost all prepolymers and monomers participated in the polymerization reaction.The analysis of relative molecular weight and distribution showed that the mass average molecular weight(Mn)and weight average molecular weight(Mw)decreased with the increasing reaction temperature,but the distribution coefficient(PDI)remained between 3.56～3.79,and there was no obvious correlation between the change of PDI and temperature.The Tg determined by DSC analysis was-63.53℃,which was much lower than the Tg of PSA reported in other studies(-30～-50℃),and the applicable temperature lower limit was significantly reduced.(2)Overall,when the dosage of AA and AOI was 1.0%and 0.16%,respectively,and the Mw of prepolymer was about 457,000,the comprehensive performance of PSA was relatively optimal.The rheological properties at different frequencies explained the intrinsic relationship between pressure-sensitive performance and viscoelasticity.
万方数据
维普
