Preparation, characterization and thermal properties of tetramethylbisphenol F epoxy resin and mixed systems

Tetramethylbisphenol F epoxy resin (TMBPFE) was successfully synthesized based on tetramethylbisphenol F (TMBPF) and epichlorohydrin with tetrabutylammonium bromide as the catalyst. The structure of TMBPFE was characterized by Fourier transform infrared spectroscopy, nuclear magnetic resonance and elemental analysis. Then, a mixed system composed of TMBPFE and 4,4'-diglycidyl (3,3',5,5'-tetramethylbiphenyl) epoxy (TMBP) was prepared by a melting method, i.e. without any solvent. Both the TMBPFE and the mixed system were cured using 4,4'-diaminodiphenyl methane (DDM) as the curing agent. The thermal properties of TMBPFE and the mixed system were studied using differential scanning calorimetry, dynamic mechanical analysis and thermogravimetric analysis (TGA). The results showed that the TMBP mixed in the TMBPFE matrix had little effect on the thermal properties of TMBPFE. However, the glass transition temperature improved markedly with increasing content of TMBP. Moreover, the TGA results showed that the degradation characteristics of TMBPFE resins did not seriously decrease when TMBP was incorporated into the TMBPFE matrix, although there are large steric hindrance biphenyl groups in TMBP. Both TMBPFE and the TMBPFE/TMBP system have potential applications in electrical and electronic fields. A composite system composed of TMBPFE and TMBP was prepared. Tg improved a lot with increasing the content of TMBP. The composite systems exhibited excellent thermal property.