Direct characterization of phase behavior and compatibility in PET/HDPE polymer blends by confocal Raman mapping

Abstract

Morphology, chemical distribution and domain size in poly(ethylene terephthalate)/high-density poly(ethylene) (PET/HDPE) polymer blends of various ratios prepared with and without maleic anhydride have been analyzed with confocal Raman mapping and SEM. The ratioimage method introduced here allows us to obtain enhanced chemical images with higher contrast and reliability. Compatibility numbers (N c ) are calculated to evaluate the compatibility of the blends. The incompatible polymer blends show heterogeneous distribution with phase separation behavior, while the semicompatible blends prepared with maleic anhydride show much smaller subphase distributions with less distinct interphases. After the blending modification by maleic anhydride of only 0.5%, the viscosity status and dispersibility between PET and HDPE could be substantially improved, and the interactions that exist between the two phases have also been proved by ATR-FT-IR results. High-spatial-resolution confocal Raman mapping coupled with the ratioimage method provides a very attractive way to characterize the compatibility and phase behavior of the polymer blend through different blending methodologies.

Vibrational Spectroscopy Imaging in Polymers

“…The dissimilarity curves during the corresponding clustering processes are shown in Figures 14.25bFi, 14.26bFi, 14.27bFi, 14.28bFi and 14.29b, respectively [34]. It is observed that there are several leaps in the curves that correspond to the number of clusters in the image data.…”

“…Huan et al [34] studied phase behavior and compatibility in PET/HDPE polymer blends by using confocal Raman mapping. Maleic anhydride-grafted high-density poly(ethylene) (MAH-HDPE) was prepared by melt mixing HDPE with MAH and peroxide at 220 C [51].…”

“…The spatial directed agglomeration clustering was implemented for the segmentation of Raman mapping data measured on the 50% HDPE-50% PET incompatible blend. Figure 14.23a shows an optical image of 50% HDPE-50% PET polymer blend prepared with maleic anhydride [34]. Figure 14.23b illustrates reliability curve for 50% HDPE-50% PET polymer blend prepared with maleic anhydride and Figure 14.23c depicts the dissimilarity curve for the polymer blend.…”

“…The correlation map of the polymer blend with respect to the representative spectra of cluster 2 is shown in Figure 14.23e. Figure 14.24 illustrates the projections of the normalized spectra on the first two PCs for 50% HDPE-50% PET polymer blend prepared with maleic anhydride [34].…”

Recent advances in linear and nonlinear Raman spectroscopy II

“…A variety of special vibrational studies were reported in this reviewed JRS volume: direct characterization of the phase behavior and compatibility in polyethylene terephthalate (PET)/high-density poly(ethylene) (HDPE) polymer blends by confocal Raman mapping, 110 vibrational analysis of ethylene thiourea which provided information on the electronic distribution of nonresonant Raman excited virtual states, 111 theoretical and experimental investigations of the adsorption behavior of thiophenol on gold nanoparticles including the complete assignment of thiophenol fundamental modes, 112 correlation of the methane Raman 1 band position with fluid density and molecular level interactions, 113 Raman spectroscopic investigations of 3-(pent-1-enyl) methyl ether and four deuterium-labeled analogs enabling the correlation between specific structural features and the associated Raman bands. 114 …”