Preparation Of P(WPS/VAc) With Bigger Microspheres By Suspension Polymerization And Their Properties

In daily life,waste polystyrene foam (WPS) is widely used in many fields, such as packaging, thermal insulation, waterproof, shockproof materials,etc.So it is one type of the plastics,which production increases rapidly. On the other hand, WPS has caused lots of environmental pollutions because it is not easy to decompose in nature after one-time use. In this study,be to aim for protection environment and reducing the production cost, the preparation technology of bigger P(WPS/VAc) microspheres by suspension polymerization of VAc and waste polystyrene foams was studied,and a series size of P (WPS/VAc) polymer bead bigger than traditional size (0.5mm) were prepared.This method fills the market blank of large particles of P(St/VAc), and broadens the area of technology in polymer plastic solid waste recycling, and has important theoretical and practical significance. For the present, many research workers focused on the preparation of the microspheres at the size of nano and micron, therefore the preparation of large size of microspheres will be hot in in the future.So the study on the conditions of the preparation of large particle size and beads polymerization rate of products has important theoretical significance.In the study of suspension polymerization, the effects of amount and varieties of dispersants, content and varieties of initiators,tirrer speed,ratio of oil-water, electrolyte and amount of styrene on ratio of product,rate of bead products and the size of beads were investigated. The results showed that:in the high viscosity of monomer phase, CaCO3, HAP, PVA, CMC and other single dispersant was not enough to sustain the stability of the system,but followed addition order of inorganic dispersant after inorganic dispersant,we get narrow diameter distribution of larger beads; choosed compound dispersants of HAP and CMC with larger surface tension,we gained bigger size of beads than compound dispersants of PVA and HAP;to control the time of adding HAP in a certain range of monomer conversion ratio,we acquired larger of average particle size of beads polymer, but bead products ratio reduced; As the content of NaCl, content of the water or stirring speed increased, the average size of bead reduced, but the change of rate of products and ratio of bead products was complex. As the content of AIBN or reaction temperature increased, the average size of beads increased, and the mean square deviation quality and ratio of bead products had a extreme value;as crosslinking agent DVB used, the average size of beads increases, but their surface becomed coarse, and the mean square deviation quality increased. The water-solubility of VAc affected the ratio of bead product, because VAc of10%content occured reactions in droplets but still remained in water phase.Solvent method was taken to inspect the product compatibility of polymerization, studies showed that the experimental product had better compatibility than PS/PVAc polymer that was dissolved and mixed directly.DSC analysis results showed that two of the glass transition temperature of experimental product, the one was closed to glass transition temperature of pure PVAc. and the other was moved to glass transition temperature of WPS with content of WPS increasing. The thermal properties and microscopic structure of experimental products were studies by TG-DTG.