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Abstract
A kinetic model of three-dimensional block-polymerization of multifunctional monomers until high state of conversions has been suggested. The model is based on the conception of microheterogeneity of the polymerizing system and a special role of the interphase layer on the border of solid polymer-liquid monomer. The initial assumptions are: (a) the observed polymerization rate is a sum of rates of homophase process taking place in the volume of liquid monomer according to the classical kinetic scheme with the quadratic chain termination, and of a heterophase process taking place in the inter-phase layer in the regime of gel-effect; (b) the clusters of solid polymer in the liquid monomer phase and clusters of liquid monomer in a solid polymer matrix have a fractal structure; (c) the gel-effect in the interphase layer is related to the radical decay rate decrease, and transition of the chain termination control to the rate of chain propagation control. Because of this, the kinetic scheme of the process in the interphase layer incorporates only the elementary reactions of chain propagation which also fulfill the functions of the active radicals decay reactions in the act of their deactivation and function of the reaction initiation of the secondary active radicals from the ‘frozen’ state as the result of their growth into the reaction zone. The obtained kinetic equations for the stationary and nonstationary regime of the process explain all the basic features of the block-polymerization until high states of conversion.