荧光探针法研究核壳结构有机硅-丙烯酸酯乳液的聚合行为

以芘为荧光探针,探讨了有机硅-丙烯酸酯核壳乳液聚合过程中,芘的第一振动峰(373 nm处)与第三振动峰(384 nm处)荧光强度的比值I1/I3与乳化剂、有机硅单体(D4)和引发剂(KPS)用量之间的关系,并结合聚合过程中探针芘的I1/I3峰值与单体转化率及乳胶粒形态演变之间的关系,研究了核壳结构有机硅-丙烯酸酯乳液的聚合行为.研究结果表明,探针芘的I1/I3峰值随乳化剂用量,D4用量,KPS用量不同发生相应的变化,随单体转化率的增加而增大.当乳化剂用量、D4用量、KPS与总单体的质量比依次为2 g、8 g、0.7%时,得到的乳液具有优良的综合性能.聚合反应过程中,当种子乳胶粒转变为核壳乳胶粒时,芘的I1/I3峰值仍呈现出明显的转变,说明有机硅-丙烯酸酯核壳乳液具有互穿聚合物网络结构.因此,荧光探针可用于研究有机硅-丙烯酸酯核壳乳液聚合反应进程.

STUDEIS ON POLYMERIZATION BEHAVIOR OF ORGANOSILICON-ACRYLATE LATEX WITH CORE-SHELL STRUCTURE USING FLUORESCENCE PROBE TECHNIQUE

The relationship of the amounts of emulsifier,organosilicon monomer octamethylcyclotetrasiloxane(D_4) and initiator(KPS) with the ratio of fluorescence intensity between first vibronic peak of pyrene(λ= 373 nm) and third vibronic peak of pyrene(λ=384 nm) I_1/I_3 was discussed during the emulsion polymerization process,in which pyrene was used as a fluorescence probe.The polymerization behavior of the organosilicon-acrylate latex with core-shell structure was investigated on line with the relationship of monomer conversion and development of morphology in latex particles with the value of I_1/I_3 for probe pyrene during the polymerization process.It showed that the values of I_1/I_3 for probe pyrene changed with changing the amounts of emulsifier, D_4,KPS and increased with increasing the monomer conversion.A good performance emulsion was obtained while the amounts of emulsifier,D_4,mass ratio between KPS and the whole monomer was 2 g,(8 g) and 0.7%,respectively.The values of I_1/I_3 for probe pyrene also changed obviously when the morphology of latex particles transformed from seeded latex particles into core-shell latex particles during the polymerization process.That means the organosilicon-acrylate latex with core-shell structure exhibits an interpenetrating polymer network(IPN) structure.Therefore,fluorescence probe technique can be used to study the progress of the polymerization behavior of organosilion-acrylate latex with core-shell structure.