Research On The Modified Synthesis Of Water-based Acrylic Resin

In recent years, the application of plastics is growing. However, the defects of plastics make it necessary for the "second decoration". Because of the limit VOCs emissions requirements, water-based paint has developed rapidly, which provides a huge market in the plastic coating area using water-based paint instead of solvent-based paint.This study aims to synthesize the industrial water-based emulsion with excellent adhesion, good wipe of ethanol-resistant and low-cost, for the application of environmental water-based non-toxic plastic coating.In this thesis, the single modified hydroxy acrylic emulsion with a core/shell urea-performance structure is made by the method of pre-emulsified semi-continuous seeded emulsion polymerization. The influence of emulsion polymerization, initiator and functional monomers impact on content of the emulsion coagulation rate, polymerization conversion rate, emulsion viscosity, particle size and water absorption were studied thoroughly; The composition and structure of the polymer were characterized by Fourier Transform Infrared Spectroscopy (FT-IR), Transmission Electron Microscopy (TEM) and Laser Particle Size Analyzer. Two component water-based coatings were prepared by the reaction of the emulsion and the hydrophilic polyisocyanate curing agent. The impact of curing agent type and the total amount of NCO/OH on the properties of the film were studied by FT-IR techniques. The curing reaction of the film was observed by Scanning Electron Microscopy (SEM).The best conditions for the synthesis of edified styrene-acrylic emulsion is as follows: with the-Pre-emulsion semi-continuous seed emulsion polymerization process, the reaction temperature of 78℃,2.7% emulsifier (anionic/non-ionic type=2:1),2% urea monomer,-OH content 1%, and 4% cross-United monomer vinyl triethoxysilane, The result of low temperature curing application in the polarity plastic with water-based isocyanate under NCO/OH=1.4:1 show that the coating on the adhesion is up to 15%, the hardness is up to H, and water resistance meets the standards and wipe of ethanol-resistant 50 times or more. The above self-made coating was compared with the commercially available solvent-based plastic coating. The gloss of water-based paint is not good enough, but it has the advantages of environmental benign and solving the problems of poor adhesion and poor wipe of ethanol-resistant exiting in the current water-based plastic.Water-soluble acrylic resin was synthesized by solution polymerization. The resin was modified by phosphate functional monomer with flash corrosion resistant and anti-rust. Thus, the water-based acrylic shortcomings of the resin were decreased, the adhesion and salt spray resistance of acrylic resin was improved greatly. In the experiment of phosphate functional monomer water-soluble acrylic resin copolymerization, the influence of different dosage of initiator and functional monomers contenting on the performance of resin was discussed. The results show that:with the sub-feed method, the reaction temperature of 100℃, reaction time of 5 h for synthesis of water-soluble modified acrylic resin, the monomer conversion rate reaches 95%; when the phosphate functional monomer's content is 4% and the reaction-based mission-OH content is 3%, the performance of modified resin used in the metal is best, with the hardness of 3H, zero adhesion, water resistance 120h and salt spray resistance of 240h.