Study On Preparation And Poperties Of Polymer/Inorganic Nanocomposites

Poly methyl methacrylate (PMMA) is the most important material among the acrylicresin. It is one of the most widely used plastics in many areas. On the other hand, it can not be used in some special situation for its inherent limitation, such as the low rigidity of the surface, poor attrition-resistant ability. As the inorganic nanoparticle was encapsulated by PMMA, the performance of the nanocomposite not only could advance its uvioresistant line emission, but also enhance its mechanics and thermal properties. The nanocomposites combine the advantages of the inorganic materials (rigidity,high thermal stability and unique optical, electronic and magnetic properties) and the organic polymers (flexibility, dielectric, ductility and processability), which is different with the single material and conventional composite materials. Moreover, these polymer/inorganic nanocomposites have potential application in electronic, optical, optoelectronic and nonlinear optical fields because the inorganic particles are well dispersed in polymer matrix in nanometer scale. But because of inorganic particles' smaller dimension, bigger specific surface area, higher interfacial energy, they are prone to agglomerate, and consequently cannot exert nanometric effect to full extent. Thus lowering the interfacial energy of nanoparticles, weakening interfacial polarity of nanoparticles and improving compatibility between nanoparticles and polymer become the key technological problems for composite materials. Then, how to enhance the mechanical and thermal properties of PMMA has become a hotspot among the researchers. The work goals of us are to improve compatibility between nanoparticles and polymer, to enhance the mechanical and thermal properties of PMMA, to enlarge the application of PMMA.In this paper, we select nanometer titanium powder as initiative material, modify nanoparticles with silane coupler and organic/inorganic proceses, then poly (methyl methacrylate)/nanocomposite were prepared by two methods. The mechanicas property and thermal stability were investigated by the thermo gravimetric analysis and mechanical property. The main research results as following:(1)Silane coupling agent (KH570) was used to modified nanosized TiO₂ and the influences of these factors (the content of silane coupling agent, PH, modification time) were studied. Then nanosized TiO₂ particles were modified with organic/inorganic method, the mechanism and process of modification were analyzed.(2)The nanocomposite particles with core (nano inorganic particles)-shell (PMMA) were prepared by emulsifier-free polymerization, The effects of many factors such as amount of inorganic nanoparticles, MMA, initiator, drop method of monomer and temperature on emulsifier free polymerization were investigated. The structure and the mechanism of the nanocomposite particle were studied.(3)Poly (methyl methacrylate)/nanocomposite were prepared by in situ Polymerization. The influence of the content of the inorganic nanoparticles on the mechanical property and thermal stability of the composites was investigated by the thermo gravimetric analysis and mechanical property. The kinetics for the thermal degradation of the nanocomposites were studied.