Latent curing epoxy system with excellent thermal stability, flame retardance and dielectric property

By Ying-Jun Xu, Li Chen, Wenhui Rao, Min Qi, De-Ming Guo, Wang Liao, Yu-Zhong Wang. Chemical Engineering Journal, 2018

215 citations recorded by the source corpus.

Abstract To obtain a latent curing epoxy system with satisfactory thermal stability, flame retardance and dielectric properties, imidazolium dibenzo[c,e][1,2]oxaphosphate (IDOP) was synthesized by a facile way and utilized as a latent flame-retardant curing agent for epoxy resins (EP). It was confirmed that IDOP/EP one-pack system kept reactive inert near room temperature and cured efficiently under heating with a moderate heat release. The curing procedure was explored by X-ray photoelectron spectroscopy (XPS), confirming that the flame-retardant group was incorporated into epoxy chains by covalent and/or ionic bonds, hence the intrinsic flame retardance and excellent thermal stability were given to the cured resins finally. With only 15 wt% IDOP additions, the limiting oxygen index (LOI) increased to 37.0% from 20.5% of the reference sample, and UL-94 V-0 rating was achieved. The results of cone calorimetry test further certified that IDOP/EP showed satisfactory flame retardance dominating in gaseous phase, which was confirmed by the results of thermogravimetric analysis/infrared spectrometry (TG-IR). The thermal mechanical behavior of IDOP/EP was also evaluated by dynamic mechanical analysis (DMA). Especially, the incorporation of the flame-retardant group didn’t deteriorate the dielectric properties of the cured resin. Benefiting from the advances, the latent curing epoxy system with excellent comprehensive performance exhibited potential for versatile applications.

Subfields: Mechanical Engineering, Polymers and Plastics

View Paper: https://www.semanticscholar.org/paper/07ccb407f4e99d24ea8d52a84a75009fd2f762a7

Citations in the corpus