부산대학교 도서관

The properties of the epoxy resin can be adjusted over a wide range based on the ingredient selection. In this work, kinetics of thermal degradation, adhesion, and dynamic-mechanical properties of polyetheramine (PEA)-modified epoxy networks have been discussed. Two types of PEAs, namely poly(ethylene glycol) amine (PEG-AM) and poly(propylene glycol) amine (PPG-AM), with molecular weights of 200 g/mol and 400 g/mol, were applied in epoxy modification. According to dynamic mechanical analysis (DMA) measurements, the incorporation of PEAs at 15 phr decreased crosslinking density (ν) and glass transition temperature (Tg) of the networks by 35.3% and 31.4%, respectively. The values of Tg obtained from Fox-equation for PEA-modified networks were overestimated, demonstrating enhanced interaction in the system. The thermal durability of the epoxy networks was investigated using thermo-gravimetric analysis (TGA), and activation energy of decomposition (Eα) was estimated by the integral isoconversional approach. The Eα values of the epoxy/amine system decreased from 199.3 kJ/mol to 165 kJ/mol with the incorporation of 15 phr PEG400-AM into the epoxy network. The adhesion behavior of the samples was studied using the single lap joint (SLJ) test, where two kinds of behaviors were observed in contradiction to mechanical properties. The sample with 15 phr PEG200-AM had a relatively higher lap shear strength (15.46 MPa), while the one with 15 phr PEG400-AM had the highest toughness but lower lap shear strength of 12.41 MPa. This study opens new horizons to design high-performance epoxy adhesives and composites. [ABSTRACT FROM AUTHOR]