THE INFLUENCE OF CHAIN CONFIGURATION AND, IN TURN, CHAIN PACKING ON THE SORPTION AND TRANSPORT-PROPERTIES OF POLY(TERT-BUTYL ACETYLENE)

A series of poly(tert-butyl acetylene) (PTBA) polymers was prepared with cis contents, as characterized by C-13 NMR spectroscopy, ranging from 44% to 100%. The sorption and transport properties of propane in this systematically varied series were determined by a sensitive gravimetric sorption technique. As the cis content of the polymer increased, propane solubility and diffusivity decreased markedly and the d-spacing, determined by wide angle x-ray diffraction spectroscopy, decreased monotonically with increasing cis content, suggesting that higher order molecular structure, related explicitly to configurational variations, may strongly influence chain packing in these rigid, glassy materials and, in turn, sorption and transport properties of small molecules in this polymer series. (C) 1993 John Wiley & Sons, Inc.