Study On Hyperbranched Photopolymerization Of Acrylates

Compared with the liner polymer, hyperbranched polymer(HBP) exhibits a great many outstanding performances, such as low viscosity, high flowability, good solubility. With its highly branched structure, HBPs also exhibit a lot of reactive end groups which can be modified and many hole structures within the molecule. For these special properties, HBPs are widely used in the area of paints, nanomaterials,medicines, catalysts and so on. Meanwhile, comparing the light curing technology and the traditional heat curing technology, light curing technology possesses the advatages of “5E”——Enabling, Economical, Efficient, Energy Saving and Enviromental Friendly. It is mainly used in UV-curing coatings, UV-curing adhesive, UV-curing printing inks, 3D printer and electrical materials. As the extension of light curing technology, the UV-curing HBPs have been got a great deal of attentions in the world research.However, In the light curing system, photoinitiators used have many limits, such as disperal unifomity, compability with the monomer and resin, and the fragment migration after its decomposition. To solve these problems, we fully take advantages of the excellent light curing technology and the outstanding performances of HBP,introducing the photoinitiator into the monomer which can conduct the hyperbranched polymerization. Finally, we got the self-induced monomer of hyperbranched polymerization.The research mainly includes the following three parts:Based on the commercial photoinitiator Darocur 2959[2-hydroxy-4’-(2-hydroxy ethoxy)-2-methyl-propiophe], an acrylated cleavage type radical photoinitiator called A2959, can also be a self-induced monomer, has been synthesized. The structure of A2959 was characterized by NMR. DPC was used to invested the photopolymerizaiton kinetics of A2959, the results shows the initiatied property was almost equal to D2959. The polymer can acquired by self-cleavage and initiation of A2959. But this photopolymerization is easy to produce crosslinking polymerization.It can delay the crosslinking time by adding thiododecyl alcohol.Study the photopolymerization of A2959 and methyl methacrylate. The product was analyzed by 1H NMR and GPC. The paper shows that HBP can acquired, the molecular weight of HBP can reach to 30000 after irradiating 10 minutes, to 50000 after irradiating 20 minutes, also shows the most suitable concentration of A2959 is5%.Polymerizable urethane photoinitiator(A2959) was acquired based on D2959,IPDI and hydroxyl acrylic ester. A2959 includes the acrylate groupe, urethano and photo-initiation groupe. Hyper-branched structure can be acquired after irradiation,which exhibit some new properties. The paper studys the differences between the co-curable film of ACU2959 and other three acrylate monomers and the curable film of acrylate monomers. The properties of curable film were analyzed by Tg, DSC and DMA. The analysis shows that co-curable film of ACU2959 and acrylate monomers has better thermostability, higher Tg, better storage modulus.