Study on the effect of side-chain group on the segmental dynamics of selected methacrylate polymers at ambient and high pressures

摘要

In this work, we have investigated the effect of changes in the side groups within the polymer chain on the glass transition dynamics of selected methacrylate polymers. The relaxation dynamics of the studied polymers: poly (glycidyl methacrylate), poly (hydroxy-propyl methacrylate), poly (isopropyl methacrylate) and poly (n-propyl methacrylate), was investigated with the use of dielectric spectroscopy and differential scanning calorimetry. In addition to that, high-pressure dielectric measurements were performed to understand better the effect of density changes on the segmental dynamics within the studied family of compounds. A comparison of poly (isopropyl methacrylate) and poly (n-propyl methacrylate), that have the same chemical composition while differ only in the molecular orientation of the side-chain group, has revealed pronounced differences in the glass transition temperature of almost 26 K and sensitivity of the segmental dynamics to pressure changes.