Measurements of thermal emissivity of polymers

Abstract

In order to clarify various factors which affect thermal radiation of polymers, this series of studies have been made in relation to chemical structures, surface roughness, degrees of polymerization, crystallinity and melting of polymers. Results in this report show that the thermal radiation of polymers is very susceptible to the chemical structures; with the increase in sample thickness, the emissivity increases and approaches the value of blackbody. Generally speaking, the emissivity of polymers with multiple bonds increases gradually with increasing thickness, while the emissivity of polymers without multiple bonds increases remarkably in a range of small thickness and levels off in the thickness more than about 50 μ. Among polymers containing fluorine, poly(vinylidene fluoride) has the largest emissivity while polytetrafluoroethylene has the smallest one and poly(vinyl fluoride) has an intermediate value. The emissivity of polybutene-1 is fairly low, being nearly equal to that of polypropylene. © 1975, The Society of Fiber Science and Technology, Japan. All rights reserved.