Phase structure and miscibility in blend of poly(4-methyl styrene) with poly(cyclohexyl methacrylate)

Thermal analysis, optical and scanning electron microscopy were performed t o characterize solution-blended poly(4-methyl styrene) (P4MS)/poly(cyclohex yl methacrylate) (PCHMA) of full compositions. It is concluded that the tru e state of blend phase structure is miscibility with non-specific intermole cular interactions. To probe molecular interactions between the polymer pai rs, FT-IR analysis was also used to assess possible evidence. The FT-IR res ults for the P4MS/PCHMA suggest that the intermolecular interactions betwee n the pairs are likely non-specific and only comparable with those among th e homopolymer molecules. Casting temperature did not seem to have any effec t on the miscible phase structure of P4MS/PCHMA. Both optical microscopy an d SEM characterization revealed that solution casting of P4MS/PCHMA at eith er temperature yielded equally homogeneous phase structure. The cloud point phenomenon is attributed to a thermodynamic lower critical solution temper ature (LCST) but is kinetically irreversible at normally accessible time sc ales. The observed LCST could be made to be reversible in an appropriate en vironment when the molecules were given enough molecular mobility. (C) 1999 Published by Elsevier Science Ltd. All rights reserved.