Formation of star-like water-soluble polymeric structures in the process of radical polymerization of N-isopropylacrylamide in the presence of C60

Abstract

The formation of star-like N-isopropylacrylamide (NIPA) polymeric structures in the presence of C₆₀ occurs in two steps. In the polymerization induction period, water-insoluble cores of future star-like polymers (SP) are formed. The cores are composed of one or more C₆₀ molecules linked by a C—C bond, five or six initiator radicals, and several short NIPA polymeric chains. The formation of SP begins after the induction period and continues until the end of polymerization through gradual growth of the polymeric layer at the cores. The solubility of SP in water is determined by a certain initial concentration of NIPA. It is suggested that the mechanism of these processes is determined by a dependence of C₆₀ reactivity on the degree of its “substitution”.