THERMAL DEGRADATION OF EPOXY RESINS
ISOTHERMAL HEAT-AGING TECHNIQUES AND THERMOGRAVIMETRY WERE USED TO DEMONSTRATE THE RELATIONSHIP BETWEEN RESIN STRUCTURE AND THERMAL STABILITY IN MDA-CURED EPOXY RESIN SYSTEMS. NOVOLAC EPOXY RESINS, WHICH HAVE METHYLENE GROUPS BETWEEN THE BENZENE RINGS IN THE BISPHENOL SEGMENTS OF THE RESIN, EXHIBITED BETTER THERMAL STABILITY THAN A BISPHENOL A TYPE RESIN, WHICH HAS AN ISOPROPYLIDENE GROUP BETWEEN THE BENZENE RINGS IN THE BISPHENOL PORTION OF THE MOLECULE. THERMAL STABILITY WAS ALSO INFLUENCED BY THE FUNCTIONALITY OF THE EPOXY RESIN. A NOVOLAC EPOXY RESIN HAVING A FUNCTIONALITY AVERAGING 3.2 EPOXIDE GROUPS PER MOLECULE EXHIBITED BETTER RESISTANCE TO THERMAL DEGRADATION THAN DID EPOXY RESINS BASED ON DIFUNCTIONAL NOVOLAC OR BISPHENOL A. RADIOTHERMAL ANALYSIS WAS USED TO DETERMINE THE RELATIVE THERMAL STABILITY OF HEATLABILE GROUPS IN BISPHENOL A EPOXY RESINS. THE THERMAL STABILITY OF THE ISOPROPYLIDENE GROUPS IN THE BISPHENOL SEGMENTS OF THE RESIN WAS FOUND TO BE GREATER THAN THAT OF THE REACTED GLYCIDYL GROUP UNDER BOTH OXIDATIVE AND NON-OXIDATIVE CONDITIONS, USING EITHER METHYLENEDIANILINE (MDA) OR PHTALIC ANHYDRIDE AS THE EPOXY CURING AGENT. STUDIES FURTHER INDICATED THAT THERMAL DEGRADATION OF THE ANHYDRIDE-CURED RESIN WAS INITIATED BY BREAKDOWN OF THE ESTER LINKAGE BETWEEN THE RESIN AND CURING AGENT. /AUTHOR/
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Supplemental Notes:
- Vol 44, No 12, PP 127-129, 132, 163-164, 5 PP, 15 FIG, 3 REF
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Authors:
- Bowen, D O
- Publication Date: 1967-8
Media Info
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Serial:
- Modern Plastics
- Publisher: McGraw-Hill, Incorporated
Subject/Index Terms
- TRT Terms: Curing agents; Epoxy resins; Esters; Groups of organic compounds; Metal heating; Network links; Radioactivity; Thermal analysis; Thermal stability
- Uncontrolled Terms: Degradation; Heat treatment; Linkages
- Old TRIS Terms: Isopropylidene; Methylene groups
- Subject Areas: Geotechnology; Highways; Materials;
Filing Info
- Accession Number: 00216242
- Record Type: Publication
- Files: TRIS
- Created Date: Jan 16 1994 12:00AM