Accession Number : AD0722055
Title : Polyacrylonitrile Precursor Fibers for Conversion to High Modulus, High Strength Fibers. Volume I: Thermal Analysis.
Descriptive Note : Rept. for Oct 69-Feb 70,
Corporate Author : AEROSPACE CORP EL SEGUNDO CALIF LAB OPERATIONS
Personal Author(s) : Gaulin,Camille A. ; McDonald,Willard R.
Report Date : 12 FEB 1971
Pagination or Media Count : 30
Abstract : The chemistry of polyacrylonitrile (PAN) polymers is of particular interest because of the use of these materials as precursors in the formation of high modulus carbon and graphite reinforcement filaments for organic materials in high strength, high stiffness composites. A study has been initiated into the mechanism of thermal degradation of the PAN polymers and has included commercially available yarn prepared from a copolymer of unknown history, and experimental fibers produced from both copolymers and homopolymers. Thermal methods, primarily differential thermal analysis (DTA) and thermogravimetric analysis (TGA), have been used to characterize the changes in decomposition mechanisms of the PAN fibers resulting from oxidative and radiation stabilization. It has been observed that unmodified PAN fibers undergo vigorous exothermic chemical change at moderate temperatures (about 310C). Irradiated PAN generally exhibits the exotherm at a significantly lower temperature. Where the exotherm is absent, this weight loss does not occur and a correspondingly high yield of carbonaceous residue results. (Author)
Descriptors : (*ACRYLONITRILE POLYMERS, THERMAL ANALYSIS), (*CARBON FIBERS, SYNTHESIS(CHEMISTRY)), DIFFERENTIAL THERMAL ANALYSIS, THERMOGRAVIMETRIC ANALYSIS, DECOMPOSITION, RADIATION CHEMISTRY, CROSSLINKING(CHEMISTRY)
Subject Categories : Polymer Chemistry
Distribution Statement : APPROVED FOR PUBLIC RELEASE