高分子微球的合成及其在密封剂中的应用

以亲水性4-乙烯基吡啶(4-Vp)为微球的壳层单体、苯乙烯(St)为微球的核层单体,采用一步无皂乳液聚合法制备了PS-P4V P聚苯乙烯-聚(4-乙烯基吡啶)]微球;然后在该高分子微球表面覆盖了一层有机硅,合成了有机-无机杂化PS-P4VP-Si有机硅包覆的聚苯乙烯-聚(4-乙烯基吡比啶)]微球;最后分别将两种微球与聚硫橡胶共混,制备相应的聚硫密封剂。研究结果表明:PS-P4VP、PS-P4VP-Si微球大小均一,两者粒径分别为290 nm和350 nm;两种微球分别作为聚硫密封剂的填料,既能提升密封剂的性能,又能降低密封剂本身的密度(比常规密封剂降低了15%～20%);同时,这两种微球填充的聚硫密封剂具有艮好的耐热性能和耐介质性能,特别是PS-P4VP-Si微球的综合性能更优异。

Synthesis of polymer microspheres and application in sealants

With hydrophilic 4-vinylpyridine(4-Vp) as shell monomer of microsphere,styrene(St) as core monomer of microsphere,a PS-P4VPpolystyrene-poly(4-vinylpyridine)]microsphere was prepared by one-step soap-free emulsion polymerization.Then a organic-inorganic hybrid PS-P4VP-Si(PS-P4VP coated by silicone) microsphere,which surface was coated by a layer silicone,was made.Finally,the corresponding polysulfide sealant was prepared by blend between a microsphere and a polysulfide rubber.The research results showed that the PS-P4VP or PS -P4VP -Si microspheres had uniformity particle sizes,and their particle sizes were 290 nm or 350 nm respectively.Two microspheres,which were used as fillers of polysulfide sealants respectively,had both enhancing properties of sealant and decreasing density of sealant self(15%-20%lower than conventional sealants).And two polysulfide sealants filled by different microspheres had good heat-resistance and medium-resistance.Especially,the properties of PS-P4VP-Si microsphere were better than those of PS-P4VP microsphere.