MOLECULAR STRUCTURE AND PHYSICAL BEHAVIOR OF POLYMERS.
Abstract
Eight model copolymers were prepared by standard ester interchange techniques. They are poly (cis-trans 1,4-cyclohexylene dimethylene sebac ates) in which the percentage of the (trans 1,4 cyclohexylene dimethylene) groups ranges from 0 to 100%. The molecular weights were estimated from intrinsic viscosity determinations and by end group analysis. They appear to lie in the range 5,000 to 8,000. The melting temperatures were measured after crystallization at various tem peratures. By an extrapolation procedure the equilibrium melting temperatures were deduced. They showed a characteristic eutectic effect, the 30% trans copolymer having the lowest melting point. The rates of crystallization varied sharp ly with the crystallization temperature. The re lations for the different polymers were displaced along the temperature axis roughly in accord with their equilibrium melting temperatures. A signif ficant molecular weight effect was observed, the lower molecular weight polymers crystallizing more slowly at a given temperature. The amount of crystallization attained was found to vary with temperature in a complex manner. Several of the copolymers showed two maxima, whereas the homo polymers apparently gave a single sharp maximum at a temperature about 20 C below the equilibrium melting temperature. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 30, 1963
- Accession Number
- AD0418648
Entities
People
- Alan Neville Gent
- M. Morton
Organizations
- University of Akron