Study On Seed Semi-continuous Emulsion Polymerization And Performance Of ASA Resin

ASA resin is a two-phase blended resin with a "sea-island" structure.The continuous phase is the SAN resin,and the dispersed phase is polyacrylate rubber particles.In industrial production,ASA resin is mainly prepared by emulsion grafting-blend method.The SAN polymer is grafted onto the polyacrylate rubber particles by emulsion grafting reaction to improve two phases compatibility;then the SAN resin and the core-shell modifier are melted and blended by means of banburying and open refining.After mixing,a variety of ASA resins are finally obtained.This paper trests ASA resin as the research object,and trests polybutyl acrylate seed emulsion and rubber particle size as the starting point to study in detail the effect of seed semi-continuous emulsion polymerization and rubber particle size on the mechanical properties and fluidity of ASA resin.Mainly did the following work:1.This chapter uses a redox initiation system to carry out the seeded semi-continuous emulsion polymerization of polybutyl acrylate.Emulsifier content and distribution,initiator distribution,feeding method,and feeding rate in the initiating system.In this paper,the seeded semi-continuous emulsion polymerization under pre-emulsion feed is divided into three stages: monomer diffusion,monomer saturation and latex particle growth,and the mechanism of seeded semi-continuous emulsion polymerization under pre-emulsion feed is inferred.The reason for the phenomenon is fully explained.2.A one-step method is used to synthesize polybutyl acrylate rubber particles ranging from 100 to 600 nm,and perform grafting reaction to prepare ASA core-shell modified particles,which are melt blended to form ASA resin.The rubber particle size has a significant effect on the mechanical properties of ASA resin.The rubber content in the ASA resin is 25 wt.%,and the impact resistance of the ASA resin is the best when the rubber particle size is 422.8 nm.After blending rubber particles with a particle size of 82.6nm and 608.8 nm,the impact value can reach up to 609.6 J/m,which has high impact resistance.The tensile strength of ASA resin is maintained at 30 MPa under the two blending systems of single-size rubber particles and large-size and small-size rubber particles.The relationship curve between the complex viscosity η*-ω and the storage modulus G’-ω of the ASA resin is related to the interface properties of the two phases,and not directly related to the size of the rubber particles.