Thermal Expansion of Amorphous Polymers at Atmospheric Pressure. I. Experimental

Abstract

The design and calibration of a simple volume dilatometer are described. It overlaps and extends to about 250" the range of our cryogenic dilatometer and thus is suitable for expansivity studies of some polymeric high-temperature glasses, the corresponding liquids, and rubbery polymers. Measurements of specific volume are accurate within f1.3 x cm3/g. The results for three methacrylate polymers are given, namely, cyclohexyl. cyclopentyl, and a highly isotactic methyl. The thermal expansivities and derived free-volume quantities are compared with each other and with previous results for homologous series of poly(alky1 methacrylates) and poly-(vinyl ethers). The typical effects in systems with linear side chains, which are reflected in reduced values of the characteristic product h T g , are not encountered in the present systems. They retain "normal" values, not withstanding the enhanced mobility of the rings.

Regression analysis studies of polymer transitions II. TII from specific heat and other data for polyisobutylene

“…These techniques were then applied to volume vs. temperature data of polycycloalkylmethacrylates using the published results of Wilson and Simha. 2 The existence of a liquid-liquid transition, Tll, lying above the glass transition temperature, T,, in these polymers, as suggested in Ref. 2, was dem0nstrated.l The present paper begins by extending these same procedures to adiabatic calorimeter data of Furakawa and Reilly on a classical, much investigated polymer, polyisobutylene (PIB).…”

Deformation behavior of oriented UHMW-PE fibers

“…The dilatometer used in this study has been described in detail elsewhere [15]. The total volume of the cell was about 15 ml.…”

Cell theory and equation-of-state of chain molecular systems: Application to polymer solids

“…Agreement between the computed lines and experimental points [27][28][29][30][31][32][33] is generally quite satisfactory for all the polymers over the entire PVT range [root mean Figure 7, the four isotherms on the low-temperature side are more or less in good accord with the experiment, whereas the fifth isotherm at the highest temperature shows systematic deviations, the computed volumes being progressively larger at higher pressures. For poly(cyclohexyl methacrylate) (PCHMA) Figure 8 shows satisfactory agreement as noted in Figures 4 -6.…”