Synthesis and curing research of propargyl-terminated PET

The hydroxy-terminated binder and multi-isocyanate curing system of traditional composite propellant is water-sensitive. To overcome this shortcoming, the hydroxyl groups are modified into propargyl groups which are used together with multi-azide to form a new curing system according to the click chemistry reaction. Molecular weight of 4000 ethylene oxide-tetrahydrofuran copolyether (PET4000) was used as a raw material. After being end-modified, propargyl-terminated PET4000 (C≡PET4000) was synthetized. Using a specific catalyst, C≡PET4000 was used to form a new curing system together with a curing agent of azide whose functionality is 3.8. The elastomers of different catalyst concentration and curing parameters were produced, whose mechanical properties were studied. It turns out that these properties are similar to the traditional ones.