Curing Study of Epoxy Resin of (2E, 6E)-Bis (4-hydroxybenzylidene)-4-methylcyclohexanone with Different Aromatic Diamines and Anhydrides Hardeners: Spectral and Thermal Analysis

By : Jalpa V. Chopda, Dharmesh B. Sankhavara, Jignesh P. Patel, Parsotam H. Parsania

Page No: 35-48

Abstract
Conventional curing study of epoxy resin of (2E, 6E)-bis (4-hydroxybenzylidene)-4-methyl cyclohexanone (EMBHBC) was conducted at 140 0/150 0C by using 4,4’-diaminodiphenylmethane (DDM),4,4’-diaminodiphenylsulphone (DDS),4-4’-diaminodiphenyl ether (DDE), p-phenylenediamine (PDA), 1,2,3,6-tetrahydrophthalic anhydride(THPA), maleic anhydride (MAH) and pyromellitic dianhydride (PMDA). The gel time for DDS, THPA and DDM hardeners are found considerably longer than those of DDE, PDA, MAH and PMDA systems indicated different reactivity towards curing of EMBHBC. Sol–gel analysis of cured resins was carried out in DMF at room temperature. Diamines cured samples showed 76.3-97.5% gel fractions, while anhydrides cured samples showed 84.6-99.6% gel fractions. DDM, PDA and THPA are found suitable hardeners for curing of EMBHBC. Cured EMBHBC samples are characterized by FTIR, DSC and TGA techniques. DSC endothermic/exothermic transitions supported either physical or chemical change as supported by TGA. Diamines and anhydrides cured EMBHBC are thermally stable up to 224–315 0C and 237–300 0C, respectively and followed two step degradation reactions except EMBHBC-PDA and EMBHBC-MAH. Diamines and anhydrides cured EMBHBC showed respectively 30–52% and 32–41% residues at 700 0C. Use of selected hardeners affected curing and thermal behavior of the cured epoxy resins under selected experimental conditions.

Authors :
Jalpa V. Chopda
Department of Chemistry, Saurashtra University, Rajkot-360 005, Gujarat, India.

Dharmesh B. Sankhavara
Department of Chemistry, Saurashtra University, Rajkot-360 005, Gujarat, India.

Jignesh P. Patel
Department of Chemistry, Saurashtra University, Rajkot-360 005, Gujarat, India.

Parsotam H. Parsania
Department of Chemistry, Saurashtra University, Rajkot-360 005, Gujarat, India.
 

DOI: https://doi.org/10.32381/JPM.2021.38.1-2.4