A STUDY ON PHOSPHORUS CONTAINING POLY AMIDE IMIDE S AND THEIR EFFECT ON THE CURING AND THERMAL STABILITY OF DIFFERENT EPOXY RESINS

Abstract

Epoxy resins are widely used as structural composites, coatings, encapsulations, newlinecastings and adhesives in a number of electrical and electronic applications. Many newlinethermoset resins have been synthesized to meet the demands of aerospace, defence newlineand electronic industries. Epoxy resins particularly, diglycidyl ether of bisphenol-A newline(DGEBA) is one of the most commonly used epoxy resin in structural applications newlinesuch as composites and laminates, primarily due to its low shrinkage on cure, fluidity newlineand ease of handling. The cured epoxy resins have good toughness and ultimate newlinetensile strength, low moisture absorption, excellent thermal stability and good flame newlineretardancy. The objective of this thesis is to perform a comprehensive material newlinecharacterization of these new epoxy resin/hardener combinations, which are newlinepotentially used as electrical insulating material in high voltage engineering. newlineThe present thesis deals with the synthesis of novel thermally stable poly(amideimide) newlines (PAIs) based on non-coplaner diimide-diacids (DIDAs) monomers. Four newlinedifferent dianhydrides pyromellitic anhydride (PMDA)/or 3,3 ,4,4 -benzophenone newlinetetracarboxylic dianhydride (BTDA)/or 1,4,5,8-naphthalene tetracarboxylic newlinedianhydride (NTDA)/or 4,4 - oxydiphthalic anhydride (ODPA) and amino acid Ltryptophan newlinewere used to synthesize diimide-diacids (DIDAs). Amines used in the newlinesynthesis PAIs, were tris(3-aminophenyl) phosphine (TAP), tris(3-aminophenyl) newlinephosphine oxide (TAPO), bis(3-aminophenyl) isopropyl phosphine (BAP) and bis(3- newlineaminophenyl) aminotolyl phosphine (BATP). The polymerization of DIDAs with newlinephosphorus containing amines having phenyl moieties gave poly(amide-imide)s of newlinevarying structures. The introduction of bulky phenyl arms along the polymer chains newlinecould increase the organosolubility and disrupt the coplanarity of aromatic units in newlinepacking of chain. These aromatic poly(amide-imide)s had excellent thermal stability, newlineamorphous behavior and are readily soluble in various organic solvents...