Effects of Molecular Weight of Dextran on Dynamic Mechanical Properties in Functional Polymer Blend Systems

Blending of natural/synthetic polymers is one of the most practical way to obtain a new material with desired properties such as thermal, mechanical and dynamic mechanical properties. Dynamic mechanical analysis (DMA) is a strong method to investigate the mechanical/viscoelastic properties, thermal transitions and compatibility in these polymer blend systems. In this study, biocompatible T10 and T40 dextran (DEX) and polymethacrylamide (PMAM) blend systems were prepared by solvent casting method. Variations of dynamic mechanical properties including storage modulus (SM), loss modulus (LM) and tan δ of the DEX/PMAM blends were investigated for all samples at a specific fixed frequency of dynamic mechanical loading in a certain temperature range. Thermal transitions and -relaxations were observed from results of DMA measurements. In general, a single glass transition temperature was observed in binary blend systems. It was found that temperature dependence of dynamic mechanical properties and curves exhibit typical behaviors and strongly depended on the molecular weight, intra- and intermolecular interactions due to the hydrogen bonding in these blend systems.