An azido-terminated polyhedral oligomeric silsesquioxane (POSS) compound, octakis(azidopropyl-3-oxycarbonyl-1-decyl-10-thiopropyl-3-)POSS (OADTP), is synthesized and characterized. POSS-polytriazole (PTA) resins are prepared from an azide, an alkyne monomer, and OADTP. The toughening effect of OADTP on PTA resins is analyzed by impact performance test and electronic microscope characterization, and the thermal performance of resins is measured by thermogravimetric analysis and dynamic mechanical analysis. The results show that the addition of the POSS can improve the mechanical properties of PTA resins. The impact strength of POSS-PTA resins first increases and then decreases with the increase in the POSS compound, and the maximum one arrives at 54.8 kJ m−2 which increases by 44.2% as compared to 38 kJ m−2 of the PTA resin. A good thermal stability remains in POSS-PTA resins.

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 0 ,N 0 -tetrapropargyl-4,4 0 -diaminodiphenylmethane (TPDDM) with 1,1-bisazidomethyl-4,4 0 -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 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 kJÁm À2 and K IC 2.57 MPaÁm À1/2 , 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 C and 0.22% respectively. K E Y W O R D Shigh performance resin for advanced composite, polytriazole resin, propargyl-terminated polypropylene glycol, toughened polytriazole resins, toughening of thermosetting resin