Accession Number : AD0714084

Title :   Thermal Analysis of Ablative Plastic Materials. Part I: Constant Heating Rate Thermogravimetry of Carbon/Graphite Cloth Reinforced Aromatic/Heterocyclic Resins to 1400C.

Descriptive Note : Technical rept. Mar 68-Dec 69,

Corporate Author : AIR FORCE MATERIALS LAB WRIGHT-PATTERSON AFB OHIO

Personal Author(s) : Farmer,R. W.

Report Date : AUG 1970

Pagination or Media Count : 166

Abstract : Applications for polyaromatic and polyheterocyclic resins and their reinforced composites include ablative thermal protection, coatings, radomes, and structures. The response of these materials in high temperature service environments was predicted by kinetics. Kinetic parameters n, A, and E were evaluated for eight carbon and graphite cloth ablative composites. An integral method computer code and a maximum rate of weight method computer code were used for this purpose. A -325 sieve, dried 80 mg powder was run at 8.5C/min to 1400C in a helium purge of 1 liter/min. The relative order of resin thermal stability was polybenzimidazole > polyphenylene > polyimide > phenylphenol formaldehyde and phenol formaldehyde. Thermograms were plotted with a third computer code to compare with the experimental one. Graphite cloth composites gave the best overall agreement. Typical residual weight difference at constant temperature ranged from 0.8% for phenol formaldehyde/graphite cloth up to 2.3% for polyimide/carbon cloth. (Author)

Descriptors :   (*HEAT RESISTANT PLASTICS, *ABLATION), (*REINFORCED PLASTICS, ABLATION), (*THERMOGRAVIMETRIC ANALYSIS, HEAT RESISTANT PLASTICS), REACTION KINETICS, BENZIMIDAZOLES, IMIDES, PHENOLIC PLASTICS, TEXTILES

Subject Categories : Laminates and Composite Materials

Distribution Statement : APPROVED FOR PUBLIC RELEASE