An atomistic model of the amorphous glassy polycarbonate of 4,4-isopropylidenediphenol

Abstract

Abstract : A detailed static atomistic model of the dense, glassy polycarbonate of 4,4'-isopropylidenediphenol ('bisphenol-A polycarbonate', PC) is simulated using a well established technique that previously proved successful for simple vinyl polymers. Initial chain conformations, which are generated using a Monte Carlo technique including periodic continuation conditions, are 'relaxed' using a potential energy minimization. Two sizes of microstructures at densities of 1. 20 g/cm3 were obtained, one with cube edge length of 18 angstrom and the other with an edge length of 30 angstrom. Detailed analysis of the minimized structures indicate intermolecular packing influences create a large variation of chain conformations different from the purely intramolecular ground states, but that it is the intramolecular energy contributions that determine which combinations can or cannot occur. The systems are amorphous, exhibiting random coil behavior, with some weak intermolecular correlations that exist on a very small scale.