Accession Number : ADA137048

Title :   TICA (Torsion Impregnated Cloth Analysis) Study of High-Temperature Thermoplastics.

Descriptive Note : Final rept. 25 Aug 82-24 Aug 83,

Corporate Author : CINCINNATI UNIV OH

Personal Author(s) : Fried,J R ; Letton,A

PDF Url : ADA137048

Report Date : 13 Dec 1983

Pagination or Media Count : 19

Abstract : Methods have been developed to obtain relaxation spectra for highly filled cloth composites by application of torsion impregnated cloth analysis (TICA) techniques. Comparison of spectra for filled and unfilled polysulfone samples suggest that polymer-filler interactions result in substantial broadening of the relaxation time distribution although there is little change in shift parameters, glass transition temperatures, or Arrhenius activation energies. In addition, TICA loss modulus measurements suggest the presence of a previously reported weak relaxational process (liquid-liquid transition) above the glass transition temperature. Dynamic mechanical measurements of polysulfone torsion bars indicate the presence of two secondary relaxations below the glass transition temperature. These include a strong gamma peak near - 100 deg C and weak beta peak near 60 deg C. Annealing or slow cooling results in a suppression of the beta peak and intensifications of the high temperature side of the gamma peak which appears to correlate with a small decrease in impact strength. Preliminary quantum mechanical calculations suggest that the gamma relaxation may represent contributions from methyl group rotations and swivel motions of isopropylidene and diphenyl sulfone moieties while more energetic diphenyl ether swivels may be responsible for the beta relaxation. No effect of thermal conditioning in the region of the liquid-liquid transition has been observed.

Descriptors :   *Thermoplastic resins, *Polysulfones, *Composite materials, *Relaxation, *Spectra, Test methods, Fillers, Fabrics, Interactions, Relaxation time, Distribution, High temperature, Annealing, Cooling, Impact strength, Liquids, Transitions, Glass, Transition temperature, Torsion bars, Dynamics, Mechanical properties, Measurement, Quantum theory

Subject Categories : Laminates and Composite Materials

Distribution Statement : APPROVED FOR PUBLIC RELEASE