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Percolation in injection molded polymer blends
Author(s) -
Arends C. B.
Publication year - 1992
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.760321302
Subject(s) - materials science , percolation (cognitive psychology) , polycarbonate , composite material , phase (matter) , percolation threshold , glass transition , polymer , percolation theory , monte carlo method , polymer blend , moduli , modulus , conductivity , mathematics , copolymer , statistics , chemistry , organic chemistry , engineering , neuroscience , electrical engineering , biology , electrical resistivity and conductivity , physics , quantum mechanics
Elastic moduli of injection molded blends of polycarbonate with poly(styrene‐co‐acrylonitrile) (SAN) have been obtained at temperatures between the glass transition temperatures of the two components. When compared with compression molded blends as a function of composition, the moduli were found to differ by as much as a factor of three at intermediate compositions. The variations are ascribed to differences in connectivity between minor component particles. The morphologies of these materials have been modeled using percolation concepts to quantify continuity of the individual phases. The effects of phase continuity resulting from composition as well as dispersed phase shape differences were evaluated. It was found that shape per se has only a minor effect on percolation. However, shape as reflected in the size of dispersed particles relative to the extent of the domain in which they reside is primary for developing a model for continuity of the phases. An empirical relation for percolation in finite domains was devised from Monte Carlo simulations. Modulus values calculated from these continuity considerations agree well with the observed data.