An Alkenyl Polyethylene Glycol Binder: Room Temperature Curing Properties via Nitrile Oxide, Thermodynamics and Kinetics Study

Reducing the stress defects of grain caused by high temperature curing is of great significance to the safety and performance of propellant. Here, a series of alkenyl polyethylene glycol copolymers (APEG) were designed and synthesized using polyethylene glycol (PEG) samples and allyl glycidyl (AGE) and glycidol as raw materials. The APEG copolymers were cured at room temperature with nitrile oxide prepared in situ from p-benzenedinitrile oxide and triethylamine. The chemico-physical properties of the precursors and cured systems were discussed. The results showed that the tensile strength, the elongation at break and hardness decreased from the case of PEG 400 to the case of PEG 4000 and increased from the case of PEG 4000 to the case of PEG 6000. And the elongation at break of the cured APEGs decreased, the tensile strength increased with the increase of curing agent’s contents. The in situ IR of this cured system was analyzed and k = 0.1888 g/(mol min) at 27°C. The initial thermal decomposition of this cured system was also discussed. The activation energy and reaction order were calculated respectively as 163.886 kJ/mol and 0.96. The results suggested that the prepared binder could be cured rapidly at room temperature and had greater heat release during high temperature decomposition. Based on the excellent room curing performance and great heat release of this work, The APEG copolymers provide a feasible strategy to solve the problems caused by the high temperature curing.