Determination of miscibility of PVC/PMMA blends

DETERMINATION OF MISCIBILITY OF PVC/PMMA BLENDS SUMMARY Keywords: Polymer Blends, Miscibility, PVC, PMMA In this study, misciblity of polyvinyl chloride) and poly(methyl metacrylate) blends was studied by viscosimetric, thermal (DSC) and spectroscopic (FT-IR) tecniques. For this purpose, blends were prepared by the method of using common solvent, and tetrahydrofuran (THF) was used as solvent. Flow times of blend solutions prepared in different concentrations (0.4 g/dL, 0.6 g/dL, 0.8 g/dL and 1 g/dL ) and different PMMA ratios ( %20, %40, %60 and %80 ) and polymer solutions and solvent were determined by Ostwald type viscosimeter at different temperatures ( 25°C, 30°C ve 35°C ). The results were evaluated by Ab parameter which is called misciblity parameter. Positive values show miscibility of blends while negative ones show immiscibility. Therefore; at 25 °C, at a concentration of 0,4 g/dl, blend containing 60% PMMA, at a concentration of 0,6 g/dl blend containing 20% PMMA, at a concentarion of 0,8 g/dl blends containing 20%, 40% and 80% PMMA and at a concentration of 1 g/dl blend containing 20% PMMA, at 30 °C, at a concentration of 0,4 g/dl blends containing 40%, 60% and 80% PMMA, at a concentration of 0,6 g/dl blend containing 20% PMMA, at a concentration of 0,8 g/dl blend containing 80% PMMA and at a concentarion of 1 g/dl blend containing 20% PMMA, at 35 °C, at a concentration of 0,4 g/dl blend containing 40% PMMA, at a concentration of 0,6 g/dl blend containing 20% PMMA, at a concentration of 0,8 g/dl blends containing 40% and 80% PMMA and at a concentration of 1 g/dl blend containing 20% PMMA show miscibility. For the miscibility studies by thermal tecniques, blends of 0.8 g/dL concentration and different PMMA contents (%20, %40, %60 ve %80 ) were examined. A unique glass transition temperature were determined for all compositions and it has been concluded that blends with different PMMA contents show miscibility. Besides, according to Gordon Taylor equation the k parameter which shows the degree of miscibility were calculated and the best miscible blend was found as the blend containing 40% PMMA. For spectroscopic studies, blends were examined by a FT-IR. From results, a shift in C-Cl stretcing region of PVC and a shift in C=0 stretching region of PMMA. These shifts show the interaction between CI atoms of PVC with oxygen atoms of PMMA, therefore miscibility of PVC/PMMA blends. Xll