Synthesis And PRoperties Of Ba～(2+)-containing Transparent Polymer Materials

Materials used in the optical members need to be colorless and transparent. Due to the excellent properties such as lightness, good transparency, impact resistance, processability, and dyeability, optical resins were extending a range of their application as transparent materials replacing inorganic optical materials in wide fields. According to the principle of the molecular design, addition of some heavy-metal ions into the polymer chains, could not only synthesize the functional materials which have radio-resistance properties or nonlinear optical properties, but could also improve the glass transition temperature and the refractive index of polymer materials.With the extensive usage of various radiations, there was much interest in the preparation of radio-protective material, especially in the study of transparent radio-protective polymer. Most radio-protective resins usually disperse metal oxide into the polymer. By this method, the metal-containing polymer exhibited good absorption for X-ray and (-ray, but it had poor strength and hardness. Also, metal oxide was easy to dissipate from materials, which would pollute environment.If metal was composed to be a component that has reaction activity, and as a monomer when added into the reaction system to synthesize copolymerized resins, the above shortcoming could be overcome. The synthesis, characterization, and property studies of this series of transparent materials, which were prepared by copolymerization with a monomer containing metal and styrene, have seldom been reported. In this paper, one kind of heavy-metal ions Ba2+ was introduced as its cinnamate with reaction activity. It was regarded as a monomer and copolymerized with styrene and methacrylic acid. So the transparent polymers that contained metal ion were successfully synthesized. In addition, the monomer-solubility phase diagrams and polymer-transparency phase diagrams of some of them were studied in detail. The optical properties, physical properties and radiation shielding properties were also discussed with different contents of monomer.For the optical properties, this kind of optical resin containing ion Ba2+ possessed good visible light transparency. There were a wide monomer-dissolved phase region and a large polymer transparent phase area for Ba(CA)2 /St /MA three-component copolymerization system. In the polymer transparent area, Ba(CA)2 content could be up to 32wt%. The metal-containing optical resins exhibited good radio-resistance properties while they had a high visible light transmittance. The optical resins that contained Ba2+ could absorb almost all X-ray and a part of (-ray with low energies.The refractive index of the homopolymer of Ba(CA)2 and MA were calculated, which were nP(Ba(CA)2) =1.643 and nPMA =1.500, respectively. Therefore the optical resins that contained Ba2+ possessed a high refractive index, and with the content of the metal salt increased in the transparent polymers, the refractive index and density increased linearly. The optical resins that contained Ba2+ possessed good thermal stability and physical properties. When the content of the metal salt increased, the glass transition temperature, the polymer decomposition temperature, the impact strength and the surface hardness of the optical resins improved obviously.