Synthesis, Characterization and Glass/Carbon Reinforcement of Acetone-Formaldehyde-1,5-Dihydroxynaphthalene-Epoxy Resin System

Acetone-formaldehyde (AF) resin containing the methylol group (-CH2OH) has been prepared and condensed with 1,5-dihydroxynaphthalene (DN) in the presence of an alcoholic alkali catalyst at varying ratios of AF:DN: 1:1, 1:1.5 and 1:2, respectively. The resultant AFDN resins were characterized by elemental analyses, IR spectral studies, and number average molecular weight determined by the nonaqueous conductometric titration method. Further reaction of the AFDN resins was carried out with different epoxy resins (i.e., DGEBA, DGEBC and DGEBF). The curing of these resins was monitored by differential scanning calorimeter (DSC) and their kinetic parameters have been evaluated. Based on DSC thermograms both glass and carbon fiber-reinforced composites have been laminated and characterized for chemical, mechanical and electrical properties. The unreinforced cured resins were subjected to thermogravimetric analysis (TGA).