Toughened polytriazole resin based on alkyne-terminated polyethylene glycol

Abstract

Polytriazole resins (PTAs) are high performance resins which have good processing performance and mechanical properties, can be cured at low temperature (70 ~ 80 ℃) and have high heat resistance. In this study, we develop a high toughness polytriazole (T-PTA) resin through chemical modification by the introduction of long-chain polyether structure, alkynyl-terminated polyethylene glycol (DPPEG), into a polytriazole (PTA) resin prepared from N, N, N, N-tetrapropynyl-4, 4′-diamino-diphenylmethane (TPDDM) and biphenyl dibenzyl azide (BPDBA). 400, 1000, 2000 number average molecular weight DPPEG were synthesized firstly. Curing behavior, thermal properties, mechanical properties and effects of monomer molecular weight and ratio on the properties of T-PTA resins prepared from DPPEG, TPDDM, and BPDBA were explored. The results show that the toughness of T-PTA resin is significantly improved. The impact strength of the T-PTA resin which uses DPPEG with a molecular weight of 1000 and the molar quantity of alkynyl group in DPPEG to molar quantity of alkynyl group in TPDDM ratio is 5:45 can reach 71.9 kJ/m2, which is 82.3% higher than the impact strength of PTA resin without DPPEG. The introduction of flexible long chain structure has no effect on the curing behavior. The glass transition temperature (Tg) and the 5% thermal weight loss temperature (Td5) are lightly decrease with the increase of molecular weight and proportion of DPPEG added. T-PTA resin has good toughness, flexural properties and heat resistance, which can expand the application of PTA resin as an advanced composite resin matrix in the aerospace field.