Study On Suspension Polymerization Of Unsaturated Polyester Resin And Polymer Beads Properties

The aim of this paper is to obtain a kind of polymer jet abrasive in micro-processing, the abrasive beads must have suitable diameter and diameter distribution, high hardness value and strength.With unsaturated polyester resin (UPR) as raw material and suspension polymerization as method, we have discussed the various factors, which affect the particle characters, such as average diameter, diameter distribution and shape. The researches involved: (1) Applicability of inorganic powder and polymer stabilizer in UPR suspension polymerization system;(2) The effects of amount of stabilizer and compound stabilizer and stabilizer assistant on polymer beads diameter and diameter distribution; (3) From the aspect of agitation, we have discussed the effects of agitation speed and agitator type and position on particles diameter and diameter distribution;(4) We also have discussed the effect of reactor type on particle size; (5) Because the raw material is often determinant factor to characters of product, we have discussed the effects of UPR type and kinds and amount of cross-linking agent on polymer beads size and diameter distribution. (6) The effects of reaction temperature and initiator amount and pre-dispersion time were also studied. (7) We have studied the main factors that affect polymer beads hardness, such as reaction time, UPR type, cross-linking agent type and amount, heat treatment and etc. From the tensile-strength and impact-strength of bulk polymerization samples we have found out indirectly the polymer beads mechanical properties, and we also discussed the effect of cross-linking agent on particles mechanical properties. By FT-IR and DSC characterization techniques, we have explained the relationship between polymer structure and properties.As the results of experiment showed, the inorganic powder stabilizers are not suitable for UPR suspension polymerization system alone, while the PVA is well for this system. With the increasing of amount PVA, polymer beads average diameter and diameter distribution is declining, but there are invariable values for both of them. A small amount of stabilizer assistant (SDBS and/or NaCl ) can improve greatly the dispersing condition. With increasing of agitation speed, beads size and size distribution is declining, but this process has a small fluctuation. Reaction temperature and pre-dispersing time have complex influences on beads size and size distribution. Round cylinder flask is beneficial for dispersing. There is a best position for polymerization when double-layer stirrer is used. The kinds of UPR and cross-linking agent have small effects on beads size and size distribution. Polymer hardness will not changed when enough reaction time passed. The hardness of samples of fumarate is higher than that of maleate. With double functional groups as cross-linking agent, such as divinylbenzene, polymer hardness increased greatly, but at the same time, mechanic properties declined some extent.