Journal of Applied Polymer Science, Vol.83, No.7, 1425-1431, 2002
Reexamination of the miscibility of stereoregular poly(methyl methacrylate) with poly(vinyl phenol)
Previously, isotactic, atactic, and syndiotactic poly(methyl methacrylates) (PMMAs) (designated as iPMMA, aPMMA, and sPMMA) were mixed with poly(vinyl phenol) (PVPh) separately in tetrahydrofuran (THF) to make three polymer blend systems. According to calorimetry data, iPMMA was found to be miscible with PVPh; however, partial miscibility or immiscibility was found between aPMMA (or sPMMA) and PVPh. According to the article by C. J. T. Landry and D. M. Teegarden, Macromolecules, 1991, 24, 4310, THF is the reason for causing aPMMA and PVPh to phase separate, but 2-butanone instead produces miscible blends. Therefore, in this article these three polymer systems were investigated again using 2-butanone as solvent. Films were prepared under specific conditions to minimize the effect of aggregation in PMMA. The formation of hydrogen bonding between PMMA and PVPh and the attendant changes in the aggregation of PMMA segments were determined in the solid states by means of FTIR. Based on the results of calorimetry, iPMMA and aPMMA were found to be miscible with PV-Ph. For iPMMA/PVPh blends, different degrees of hydrogen bonding were observed based on DSC data and FTIR spectra when compared to previous study. An elevation of the glass transition temperatures (T(g)s) of aPMMA/PVPh blends above weight average was detected and the T-g values were fitted well by the Kwei equation. But partial miscibility was still found between sPMMA and PVPh on account of the observation of two T(g)s in most compositions.