2019 Volume 47 Issue 3 Pages 111-117
We have investigated the relation between the polymer and low-mass molecule (LM) dynamics in antiplasticized polycarbonate (PC). Antiplasticization results in enhancement of the Young’s modulus of polymeric materials by adding LMs. Comparison of the dynamic mechanical properties and dielectric relaxation behavior suggests that the LMs are immobile below room temperature (~ 25 ºC) and mobile above room temperature. The LM dynamics shows a similar trend to the local chain motion of PC, indicating the dynamical relation between the two components. Additionally, we investigated the effect of the LM size on antiplasticization and the local chain motion of PC by using alkyl cyano-biphenyl with various carbon numbers and 4-pentyl-4′-cyanoterphenyl. The LM size does not affect the degree of modulus enhancement of PC at the room temperature. However, mechanical relaxation of the local chain motion of PC shows wider temperature dependence for shorter LM size. The activation energy of molecular motion decreases with decreasing LM size, indicating that restriction of the local chain motion of PC and the LMs becomes weaker for smaller LM size.
