Abstract: Living free radical polymerizations of styrene were studied with the initiator of benzoyl peroxide in the presence of TEMPO(2,2,6,6-tetramethylpiperidinyl-1-oxy). The purpose of this paper is to explore the polymerization rate enhancement by means of using additives. It was found that styrene polymerization was distinctly accelerated by the addition of small amounts of a 1,3-diketone(acetylacetone, AAT) , a β-keto ester(acetoacetic ester, AAE) or diethyl malonate(DEM) and a strong organic anhydride(trifluoroacetic acid anhydride, TFA). However, some of strong organic acid, chloroacetic acid(CAA), bromoacetic acid(BAA) and 2,4,6-trinitrophenol(TNP) did not enhance the rate of the stable free radical mediated polymerization.

Key words: Stable free radical, Living free radical polymerization, Rate-accelerating additive