Synthesis and characterization of photosensitive epoxy resins containing benzylidene and cycloalkanone moieties in the main chain

Abstract

Epoxy resins have been used successfully in a wide range of newlineapplications spanning from electronic products to advanced aerospace newlinestructures Photoreactive epoxy materials have recently gained a remarkable newlineinterest since the photochemical reactions in organic materials can induce newlinemany changes in physicochemical properties Epoxy resins are widely used newlinein industries as protective coatings The ability of the epoxy resin to react with newlinea variety of substrates gives versatility to the epoxy resins newlineIn the present study photosensitive aromatic diol monomers were newlineinitially prepared The aromatic diols 26bis4hydroxy3 newlinemethoxybenzylidene cyclohexanone BHMBCH and 25bis4hydroxy3 newlinemethoxybenzylidene cyclopentanone BHMBCP were synthesized by newlinereacting 4hydroxy3methoxybenzaldehyde with cyclohexanone and newlinecyclopentanone respectively in presence of borontrifluoride diethyletherate as newlinea catalyst in ethanol medium The monomers 26bis4hydroxybenzylidene newlinecyclohexanone BHBCH and 25bis4hydroxybenzylidenecyclopentanone newlineBHBCP were then synthesized by refluxing 4hydroxybenzaldehyde with newlinecyclohexanone and cyclopentanone respectively in ethanol medium and in the newlinepresence of the borontrifluoride diethyletherate as catalyst newlineThe epoxy resins were synthesized by a solution of aromatic diols newlinewith epichlorohydrin in presence of base catalyst The effect of the diol newlinemonomer and epichlorohydrin ratio plays a major role in the properties of newlineepoxy resins To study this effect all the epoxy resins were synthesized by newlinevarying epichlorohydrindiol monomer ratio BisphenolA based epoxy resin newlinewas synthesized by adopting the above said method to compare the properties newlinewith BHMBCH BHMBCP BHBCH BHBCP based epoxy resins The newlinecopolymers of bisphenolA and BHMBCH BHMBCP were also synthesized newlineby adopting the same procedure The reaction conditions were optimized to newlinesynthesize the epoxy resins All the monomers and epoxy resins were synthesized in good yield newline newline