Accession Number:

AD0252578

Title:

THERMODYNAMIC PROPERTIES OF POLYSTYRENE AND STYRENE

Descriptive Note:

Corporate Author:

NAVAL ORDNANCE LAB WHITE OAK MD

Personal Author(s):

Report Date:

1961-02-01

Pagination or Media Count:

25.0

Abstract:

A Tarassov function has been used to estimate the specific heat of polystyrene between 0 and 60 K and these data, together with published Cp data, have been used to calculate the entropy, enthalpy, and free energy of styrene and polystyrene from 0 to 298.16 K. Entropy of polymerization of styrene at 298.16 K was found to be 26.69 caldeg. mole. Changes in the various thermodynamic functions at the glass transition temperature, Tg, are in accordance with the second order transition as defined by Ehrenfest. The thermodynamic function CpT vs T as calculated for polystyrene increases to a maximum at 65 K and then increases agin at the glass transition temperature. An approximation is made of the heat capacity at constant pressure per vibrating unit of polystyrene at 273 K. Cp-Cv is calculated at 273 K and found to be 0.019 caldeg. gm. or 1.98 caldeg. mole. Author

Subject Categories:

Distribution Statement:

APPROVED FOR PUBLIC RELEASE