Studies on [(tetrahydrophthalated cyclohexanone-formaldehyde resin)-(epoxyresin)] condensates

Cyclohexanone – formaldehyde (CHF) resins with different hydroxyl value were treated with tetrahydrophthalic anhydride (THPA) stoichiometrically. The resultant carboxy unsaturated CHF resins were then polycondensated with various epoxy resins (i.e. diglycidylether of various bisphenols) in the presence of pyridine. The unsaturated CHF resins thus obtained and unsaturated polyesters (UPE’s) were characterized by unsaturation, spectral studies, and by number average molecular weight ( Mn ) estimated by vapor pressure osmommetry (VPO). The curing of UPE’s was carried out by using benzoyl peroxide (BPO) as catalyst and monitored on differential scanning calorimeter (DSC). Based on DSC data, glass fiber reinforced composites (i.e. laminates) of these UPE’s were fabricated, maintaining 40/60 proportion of resin to glass fiber. The laminates thus formed were tested for chemical, mechanical, and electrical properties. The unreinforced cured samples of UPE’s resins were also analyzed thermogravimetrically