The SBR seed latices with varying particls size were prepared by "cold" and "hot" emulsion polymerizations. The unreacted monomers, butadiene and styrene, were removed and the total solid content (TSC) of the latices prepared was maintained to be at 10%. Critical micelle concentration (CMC) was measured by soap titration method and the SBR seed latices were stabilized by adding soap solution (80% of CMC). Styrene(ST) and methyl methacrylate(MMA) were grafted onto back-bone activated SBR latices. Potassium persulfate was used as an initiator. Since the latex particles play as seeds, the emulsion polymerization process consists of two stages: the interval I and Ⅱ. The interval Ⅱappeared at around 80% conversion during the activated backbone process, whereas it appeared at around 60% in nonactivated, conventional process. Polymerization rate and grafting efficiency were increased in back-bone activated polymerization process. Other factors, particle size of latices, amount of initiator, chain transfer agent, and monomers, reaction temperature, and agitation rate were also investigated.

"Cold" 유화 중합법과 "Hot" 유화 중합법에 의하여 입자의 크기가 각기 다른 SBR latex를 제조하고 미반응 butadiene과 styrene을 제거한 후 Latex의 Total Solid Content(TSC)를 10%로 조절하였다. Soap titration 방법으로 critical micelle concentration(CMC)을 측정하고 CMC 농도의 80%의 Soap를 첨가하여 latex의 안정성을 증가시킨 후 활성화된 back-bone에 potassium persulfate를 개시제로 하여 styrene(ST)과 methyl methacrylate(MMA)를 graft 중합시켰다. Latex 입자가 seed로 작용하기 때문에 유화중합은 2단계 (interval I과 Ⅱ)로 이루어진다. Back-bone이 활성화되지 않은 중합에서의 interval Ⅱ는 전환율 60% 근처에서 나타나지만 back-bone이 활성화된 중합에서는 전환율 80% 근처에서 나타났다. Back-bone이 활성화된 중합에서의 중합속도와 grafting 효율은 증가되었다. Latex입자의 크기, 개시제의 양, chain transfer agent의 양, monomer의 양, 중합온도, 교반 속도 등도 연구되었다.

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