Dielectric and dynamic mechanical studies on homogeneous PBA/PBMA interpenetrating polymer networks

Broadband dielectric relaxation spectroscopy (DRS, 10(-2)- 10(9) Hz), therm ally stimulated depolarization currents (TSDC) techniques and dynamic mecha nical analysis (DMA) were employed to investigate the dynamic glass transit ion and, thus, phase morphology in sequential IPNs of poly(butyl acrylate) (PBA) and poly(butyl methacrylate) (PBMA) with 10 weight % of ethyleneglyco l dimethacrylate (EGDMA) as branching agent. In a parallel investigation, s imilar IPNs with only 0.1 % branching agent showed clearly phase separation . In the highly branched IPNs, forced compatibilization induces miscibility of the two components. The results are discussed in terms of suppression o f cooperativity and dynamic heterogeneity in the IPNs.