High‐performance semi‐interpenetrating polymer networks based on acetylene‐terminated sulfone. II. Phase separation and morphology

摘要

AbstractThe dynamic mechanical behavior, phase separation, and morphology of high‐performance semi‐interpenetrating polymer network (semi‐IPN) obtained from acetylene‐terminated sulfone (ATS‐C) and high‐performance thermoplastics have been studied by torsional braid analysis (TBA) and scanning electron microscopy (SEM). All the ATS‐C/thermoplastic blends studied are compatible before curing. The addition of ATS‐C results in a dramatic reduction in the glass transition temperature (Tg) of the thermoplastic. As the reaction of cure proceeds, the initially compatible blend passes through a stage of partial compatibility to achieve a fully incompatible semi‐IPN. SEM observation of the fracturedetched surface reveals the formation of a co‐continuous two‐phase structure in the semi‐IPNs. The connected globule and network morphology of the cured ATS‐C phase are dispersed in a matrix of the thermoplastic phase. The size of dispersed particles decreases with increasingTgof the thermoplastic. The mechanism of phase separation is discussed. ©