Synthesis And Properties Of Acrylated Polyacrylates

As the environmental situation is getting serious, coatings are developing toward to green paint in order to reduce VOC emission. Because of its unique advantages as high efficiency, energy saving, low VOC, etc. UV curable coatings are widely used for furniture, automotive refinish, optical fibers and consumer electronic products, etc.Acrylate terminated oligomers such as urethane acrylates, epoxy acrylates, acrylated polyacrylates and so on are the most commonly used resin in UV-curable coatings.Acrylated polyacrylate have the advantage of a wide range of raw materials, low cost,easy synthesis, adjustable molecular weight, good weatherability, low cure shrinkage.it can reduce the cure shrinkage and enhance the adhesion of the cured coating with the use of epoxy acrylate or urethane acrylate.In this paper, two kinds of polyacrylate were synthesized by RAFT polymerization,one is epoxy functional polyacrylates used glycidyl methacrylate(GMA) as functional monomer, another one is hydroxyl acrylic resin used hydroxybutyl acrylate(HBA) as the functional monomer. The polydispersity of polyacrylates is lower than 1.36, the molecular weight is controllable. By method of the esterification of acrylic acid and graft acrylate with urethane bond, we synthesized two kinds of acrylated polyacrylates by modification to epoxy functional polyacrylates and hydroxyl acrylic resin.Compared to method of the esterification of acrylic acid, the method of graft acrylate with urethane bond is better due to a smaller amount of catalyst, low reaction temperature and not yellowing. The results of GPC test show that the molecular weight and the polydispersity of polyacrylates have no significant increase after modification. The viscosity of the copolymer solution increase with the decrease of the molecular weight, it will reduce with the content of BA or IBOA increase in copolymer; the viscosity of the copolymer solution didn’t increase significantly before and after modification. The glass transition temperature of the polyacrylates will increase with the increase of the molecular weight; it will decresse significantly with the increase of BA in copolymer.The UV cured study of acrylated polyacrylate show that the gloss of their cured film is high, they have a good adhesion to the PMMA substrate; the higher the content of isobornyl acrylate in copolymer backbone, hardness and wear resistance of the cured film will be better, but the flexibility and adhesion of the cured film will decrease; the higher the content of double bond in copolymer backbone, the hardness,adhesion, abrasion resistance are better. This kind of acrylated polyacrylate have good high has a good comprehensive performance.