Blends of functionalized terthiophenes with polyethylene as materials for new linear polarizers

The dispersibility of terthiophene alkyl derivatives in polyethylene films was comparatively investigated by calorimetry, differential scanning calori metry (DSC) and microscopy. Polyethylene affinity of the terthiophenes incr eases with increasing linear alkyl chain length, but the increased tendency to separate crystallization gives rise to distinct phases and dishomogenei ty. Drawing of the pm at higher temperature than chromophore and poly(ethyl ene)(PE) melting points (141 degreesC) improves dispersibility with paralle l orientation of chromophore molecules and PE macromolecules. These phenome na are important in determining the high dichroism of new polymeric host-gu est polarizers based on blends of ultra-high-molecular-weight poly(ethylene ) (UHMWPE) with linear anisotropic molecules based on terthiophene nuclei f unctionalized with push-pull and alkyl groups. The PE affinity of the chrom ophores favored by their alkyl chains is one of the key factors in allowing their dispersion in the oriented poly(ethylene) films which show good perf ormances as linear optical polarizers. Copyright (C) 2001 John Wiley & Sons , Ltd.