Study On Preparation And Properties Of Polymethyl Methacrylate Nanocompsites

Polymethyl methacrylate (PMMA) is the most important material among theacrylic resin. It is one of the most widely used plastics in many areas. On the otherhand, it cannot be used in some special situation for its inherent limitation, such as thelow rigidity of the surface, poor attrition-resistant ability. So, how to enhance themechanical and thermal properties of PMMA has become a hotspot among theresearchers.In this study, the PMMA/SiO2 nanocompounds were synthesized by emulsionpolymerization. The PMMA/MMT nanocompounds were prepared by emulsionpolymerization and suspension polymerization. The effect of SiO2 (MMT) on themolecular weight of PMMA in the nanocompounds and the particle size of thenanocomposites were investigated by changing the condition of the polymerization.FT-IR, XRD and TEM were used to proved the nanostructure of the composites. Themechanical and thermal properties of the nanocomposites were investigated bystrain-stress test and TGA.The results showed that the PMMA/SiO2 (MMT) nanocompounds weresuccessfully prepared by emulsion polymerization. The exfoliated PMMA/MMTnanocompounds were synthesized during the polymerization. Some factors of thepolymerization had influence on the molecular weight of PMMA in thenanocompounds and the particle size of the nanocompounds, such as the type of themodifiers, the content of SiO2 (MMT), the type and the amount of the initiator, theamount of the emulsifying agent and the temperature of the polymerization. Themechanical and thermal properties of the nanocomposites had been enhancedcompared with the pure PMMA. They were increased with the increase of the contentof the SiO2 (MMT).The exfoliated PMMA/MMT nanocompounds were made by suspensionpolymerization. While, there were a little amount of MMT sheets, which had not beenintercalated by PMMA in the nanocompounds. The type of the initiator and the wayof the pre-soakage had some influence on the structure of the nanocompounds. Thetype of the modifiers, the content of MMT and the way of the pre-soakage had effecton the molecular weight of PMMA in the nanocompounds and the particle size of thenanocompounds. The mechanical properties of the nanocomposites increased first andthen decreased with the increase of the content of the MMT. The thermal propertieswere enhanced with the increased of the content of the MMT.