Toughening of a polytriazole resin with diprogargyl poly(propylene glycol)s

The rapid development of aerospace technology has put demands on the high tough thermosetting resins. Polytriazole (PTA) resins are a kind of high performance thermosetting resins as matrices of structural composites for aerospace parts. It is necessary to develop polytriazole resins with high toughness. In this paper, propargyl-terminated polypropylene glycols (P(t)PGs) with various molecular weights (P(t)PG400, P(t)PG600, P(t)PG725) were synthesized and characterized. A series of P(t)PG-toughened polytriazole (PPTA) resins were prepared by the Click reaction of P(t)PG and N,N,N ',N '-tetrapropargyl-4,4 '-diaminodiphenylmethane (TPDDM) with 1,1-bisazidomethyl-4,4 '-biphenyl (BAMBP). The curing behavior of the PPTA resins and the thermal, mechanical, as well as water absorption of the cured PPTA resins were investigated. The results show that the PPTA resins have excellent processing properties and can be cured and molded at 80 degrees C. The molecular weight and the amount of P(t)PG have a significant influence on the mechanical properties of PPTA resins. When P(t)PG600 with the molar ratio of alkyne groups 1.0% is formulated, the impact strength of the cured PPTA-600-1.0 resin reaches 63.6 +/- 8.2 kJ center dot m(-2) and K-IC 2.57 MPa center dot m(-1/2), which are 57.4% and 41.2% higher than those of PTA resin respectively. The glass transition temperature (T-g) and water absorption of the cured PPTA-600-1.0 resin are 223.8 degrees C and 0.22% respectively.

Automated summary

This study developed polytriazole resins with high toughness and investigated the effect of molecular weight and content of propargyl-terminated polypropylene glycols (P(t)PGs) on the mechanical properties of the resins. The results showed that PPTA resins with P(t)PG600 and 1.0% content of alkyne groups exhibited significantly improved impact strength and fracture toughness compared to PTA resin. The glass transition temperature and water absorption of the cured PPTA-600-1.0 resin were also determined.