Study On The Complex For Poly(Alkylmethacrylate)

Thermoplastic Polymethylmethacrylate(PMMA) is a commonly used material of manufacturing clinical artificial teeth. It is still widely used clinically due to the advantages of easy processing, better mechanical properties, and similar color to gingivas etc. Hydrophobic composite particles were added into PMMA in different amount in order to improve the mechanical properties of PMMA. The mechanism of improving mechanical properties of PMMA with hydrophobic composite particles was also studied in this paper.Hydrophobic composite particles were synthesized by the methacrylic acid-methyl methacrylate (MAA-MMA) copolymer emulsion reacting with the silica treated with amino silane coupling agent. Amino carboxylate was firstly generated from carboxyl in copolymer reacting with the amino group on the surface of silica, and then amide group was obtained from dewatering of amino carboxylate in the process of heating, finally, MAA-MMA copolymer was coated on the surface of silica by chemical bond. The hydrophobic degree of the composite particles was measured and its structure was identified by the FT-IR spectrum.The polysiloxane/polyether two block polyurethane was also synthesized using the polysiloxane with amino groups, polypropylene glycol and TDI. A ternary complex was obtained when the methyl methacrylate solution containing initiator and MAA-MMA copolymer(UC3000) polymerized and solidified at 50℃in the presence of composite particles and two block polyurethane. The effect of different proportions of the amount of composite particles, UC3000 and polyurethane on the hardness of ternary complex was studied. And the ternary complex was characterized by FT-IR, micro-hardness analysis, optical microscope and impact strength analysis.A ternary complex was obtained when the methyl methacrylate solution containing initiator and UC3000 polymerized and solidified at 50℃in the presence of composite particles, epoxy resin and synthetic polyurethane prepolymer. Isocyanate group can react with hydroxyl group in epoxy resin or hydroxyl group obtained in ring-opening reaction so that cross-linking and curing reaction of epoxy resin could happen.The effect of different proportions of the amount of composite particles, UC3000 and polyurethane on the hardness of ternary complex was studied. And the ternary complex was characterized by FT-IR, micro-hardness analysis, optical microscope and impact strength analysis.Hydrophobic composite particles/PMMA/polyurethane ternary complex and hydrophobic composite particles/PMMA/epoxy resin ternary complex were synthesized. The synthetic mechanism is studied, and structural characteristics are also analyzed by FT-IR and optical microscope in this paper, which showed that the two complexes have excellent mechanical properties and can be used as dental filling materials.