Persoz hardness measurements and the analysis of the temperature dependence of the storage modulus (F) for SBS di- and tetrafunctional methacrylic monomer systems were carried out to determine the distribution of the monomers in the domains or phases of the SBS block copolymer, as well as the aggregation state of each system. The forces of attraction between the monomer and the phases or domains in the matrix (similar solubility parameters with appreciable dipole-dipole and hydrogen bonding interactions) were determinant as for the monomer distribution. The influence of these structural factors on the kinetic parameters of the photoinitiated polymerization of di- and tetrafunctional methacrylic monomers in the SBS matrix was studied. (c) 2005 Wiley Periodicals, Inc.