To improve the network structure of glycidyl azide polymer (GAP) binder system

the effects of the prepolymerization of GAP with difunctional isocyanates (TDI or IPDI)

the ratio of N-100 and different curing agent on the mechanical properties

network parameters

integrity of the network

and the morphology of tensile fracture surfaces of elastomers were studied.The experimental results showed that the integrity of the network was improved by the prepolymerization of GAP with TDI

the tensile strength and elongation were improved accordingly.Defined amount of difunctional isocyanate in system can also improve the integrity of the network.By the reason of the difference of structure and reactivity between TDI and IPDI

for GAP/TDI/N-100 elastomers

the network structure was the most complete when the weight ratio of N-100 and TDI was 7:3

while the most complete network structure appeared when the weight ratio of N-100 and IPDI was 5:5 for GAP/IPDI/N-100 elastomers.The tensile strength of GAP/IPDI/N-100 elastomers was larger than that of GAP/TDI/N-100 elastomers at the same N-100 ratio

and the elongation was lower.With the decreasing content of N-100

the tensile strength of GAP/TDI/N-100 elastomers decreased from 0.66 MPa to 0.32 MPa

the elongation increased from 104.6% to 506.3%

while GAP/IPDI/N-100 elastomers exhibited maximum tensile strength of 0.69 MPa when the weight ratio of N-100 and IPDI was 7:3

and the elongation increased from 103.2% to 391.4% with decreasing N-100 content.SEM results showed that the morphology of tensile fracture surfaces of elastomers has a good corresponding relation with the integrity of the network and mechanical properties.