Tacticity effect on complex formation between tactic PHEMAs and tactic PMMAs

Abstract

Viscometric and calorimetric studies have been carried out on the complex systems of tactic poly(methyl methacrylate) (PMMA) with tactic poly(2-hydroxyethyl methacrylate) (PHEMA). The reduced relative deviation from the additivity of the viscosity, in the systems of tactic PHEMA/tactic PMMA blends which were obtained from non-acidic DMF and acidic DMF(pH=4) medium were measured in various unit mole fraction. By differential scanning calorimeter (DSC) method, we obtained the melting temperature, $T_m$ and the heat of fusion, $\triangle{H}_m$ of PHEMA/PMMA complex systems. From these results, we found that the it-PMMA/st-PHEMA blend doesn``t form the complex, and the st-PHEMA/st-PMMA and it-PHEMA/it-PMMA systems form very weak complexes. On the other hand, the it-PHEMA/st-PHEMA and it-PHEMA/st-PMMA systems form compact complexes. In it-PHEMA/st-PMMA system, the main driving force is the van der Waals force, and in the other systems the hydrogen bonding act as the main driving force. The main objective of this research is to obtain more information about the possibility and the driving force of the complex formation.