Design And Properties Of Photoinitiated Polymerization Gradient Double Bond PEGDMA Microspheres And Its Application

Dispersion polymerization is a commonly methods to synthesis monodisperse nanometer microspheres.The photoinitiated dispersion polymerization has the advantages of high efficiency with high speed and simplicity and good dispersion.In this paper,two ethylene glycol methacrylate(EGDMA)as monomer,2-hydroxy-2-methyl-1-phenyl-1-acetone(Darocurll73)as initiator,methanol as solvent,polyvinyl pyrrolidone(PVP)as the stabilizer,and monomer,solvent and stabilizer on the morphology and microspheres size of polymer microspheres were studied,and using FT-IR and SEM characterized on the morphology of microspheres and microspheres size.And in the photoinitiated dispersion polymerization process with 10mL/min oxygen,using oxygen influence the polymerization degree of polymerization,the size and morphology of pEGDMA microspheres were characterized by FT-IR,XPS,DSC and SEM.Results showed the microspheres size was increased from 270nm to 360nm,the double bond was formed on the surface of the microspheres,and the other residual double bonds were also formed in the inner of microspheres.With the increase of the microspheres size of the microspheres,the relative content of the double bond on the microsphere structure was formed gradient distribution from the interior to the surface.There are double bond in crosslinked pEGDMA microspheres from the inside to the surface and could with hydroxyethyl methacrylate(HEMA)and glycidyl methacrylate(GMA)further polymerization,FT-IR characterized the structure of microspheres,SEM and TEM characterized the size and morphology of microspheres after polymerization.The results showed that the microspheres average diameters were 510 nm and 460nm after pEGDMA microspheres polymerization with function monomer HEMA and GMA.TEM showed that the core-shell structure formed after second polymerization.Secondly,the pEGDMA microspheres as additives in TPGDA resin,through DMA and tensile testing,compared with SiO2 and PMMA microsphere,pEGDMA microspheres could make the resin Tg increased nearly 17?and also could make the tensile strength modulus of the composites increased from 324MPa to 394MPa.The paper show that the pEGDMA microspheres with double bonds could form core-shell structure with functional monomers as well as be used as additives to modify the properties of the resin.