Differences in FTIR spectrum of miscible and phase separated polymer blend of polystyrene acrylonitrile copolymer (SAN) and poly (methyl methacrylate) (PMMA)

Abstract

This work involved the studies of searching the suitable sampling preparation for quantitative analysis, the studies of the effects of phase separation and the prediction of the blending composition of unknown between styrene acrylonitrile copolymer (SAN) and poly (methyl methacrylate) (PMMA) at the weigh percent of SAN: 30, 40, 50, 60, 70, 80, 90 by using Fourier transform infrared spectrometer (FTIR). This polymer blend were prepared by melt mixing method. For the studies of searching the suitable sampling preparation for quantitative analysis by using FTIR. It was found that the film preparation method was the suitable method because it's no effects from dispersing of sample and absorbing of moisture in air. For the studies of the effects of phase separation on the IR spectra of SAN / PMMA blends. It's found that the IR spectra of carbonyl peak of PMMA at wavenumber 1732 cm-1 of miscible samples and phase separated samples were composed from five hidden peak at wavenumber 1720, 1726, 1732, 1738 and 1747 cm-1 respectively at any composition of blending. When comparing the ratio of area under each hidden peaks to area under acrylonitrile peaks, it's found that the ratio of area under hidden peaks at wavenumber 1720, 1726 and 1738 cm-1 to area under acrylonitrile peaks had the same trend. That was the ratio of area under hidden peaks to area under acrylonitrile peaks of miscible samples were higher than those of phase separated samples and found that the ratio of area under hidden peaks to area under acrylonitrile peaks were depend on the quantities of PMMA in blends, if PMMA in blend were higher these ratio were higher too. For the studies of the prediction of the blending composition of unknown between SAN and PMMA the prediction can proceed from the standard curve that plotted between the ratio of area under carbonyl peaks to area under mono-substitution group in SAN at wavenumber 702 cm-1 and weight percent of SAN in blends