Synthesis And Curing Of Acrylic Resin Using For Powder Coatings

Acrylic powder coating that its acrylic resins have excellent light resistance, weatherability, outdoor exposure durability, UV resistance does not break down and turn yellow, long-term to maintain the original luster and color, good heat resistance and Powder coating has become the focus. Acrylic powder coating of the most common type are GMA acrylic powder coating which have better properties while high prices; but the carboxy or hydroxy acrylic resin powder coatings is much more disadvantage.Acrylic resin can be synthesized from the conventional way of free radical solution polymerization, using MMA, GMA, BA and AA as monomers. Analyzing various factors including initiator, solvent, temperature, feed method, polymerization time and post-treatment method which influencing the characteristics of the resin, we have made a final selection of synthesis techniques: The ratio of GMA acrylic resin monomer: GMA: BMA: MMA = 30:20:50, The dosage of initiator of the total mass of monomer:3.5%; The ratio of carboxyl acrylic resin monomer:AA: BMA : MMA = 11:30:59, The dosage of initiator of the total monomer:5%. And the copolymerization of the resin composition, molecular weight and molecular weight distribution, softening point, glass transition temperature, such as epoxy value of the use of differential scanning calorimetry (DSC) and chemical analysis were characterized. Molecular weight of GMA epoxy acrylic resin is 7350; epoxy value is 0.21, softening point is 109℃, the glass transition temperature is 57℃; Molecular weight of carboxyl acrylic resin is 10,710, acid value is 82.54mgKOH/g, softening point is 127.9℃, the glass transition temperature is 60℃. Synthetical epoxy acrylic resin exceed the properties of similar products abroad, carboxyl acrylic resin has reached the properties of similar products abroad.Using of synthetic carboxyl GMA acrylic resin cure epoxy acrylic resin, which add zinc acetate, benzyl triethyl ammonium chloride, 2– methylimidazole or zinc acetylacetonate. we analyse the curing thermal property by DSC, calculate and compare the activation energy by dynamic model.According to the Kissinger corresponding dynamic model,we obtain activation energies of the four catalysts: 72.85kJ/mol, 66.69kJ/mol, 70.24kJ/mol, 82.45kJ/mol; the activation energy of the four catalysts based on Flynn-Wall-Ozawa kinetic model are 77.17kJ/mol, 70.55kJ/mol, 73.71kJ/mol, 85.38kJ/mol; The best catalyst is triethyl benzyl ammonium chloride.