Study On Application Of Alkyne Solidified Polyazide Glycidyl Ether Based Combustion Sublimation Pyrotechnics

Glycidyl azide polymer(GAP)is one of the most frequently studied energetic polymers,the azide group in GAP reacts with alkynes to form a triazole ring,which enables GAP to be cross-linked and cured,avoids the drawbacks of isocyanate curing,and improves its flammability and energy to a certain extent.If the alkyne solidified GAP replaces the traditional potassium chlorate energy supply system as the main energy supply component of the combustion sublimation pyrotechnic,the pyrotechnic can be formed by pouring,which can solve the problem that the special-shaped parts can not be prepared by press fitting,improve the safety of the preparation process,and improve the compatibility with the components of the reducing agent.The main research content of this paper consists of the following parts:(1)The catalytic curing reaction process of GAP and curing agent dimethyl 2,2-propargyl malonate(DDPM)was monitored by on-line infrared analysis,Fourier transform infrared spectroscopy and nuclear magnetic nitrogen spectroscopy.By obtaining the infrared spectra of the azide depletion process,the alkynyl depletion process and the N=N bond generation process,it was found that the reaction was approximately completed in 8～9h when the molar ratio of DDPM to GAP was 5:1.(2)The thermal effect of GAP curing process was tested by adiabatic acceleration calorimeter when the molar ratio of DDPM and GAP was 8:1.The results showed that the curing reaction was basically completed after curing at 60℃ for 6h.(3)By heating method and room temperature catalysis method,curing agent DDPM and GAP with molar ratios of 2:1,4:1 and 8:1 are used for curing reaction.The tensile and compressive properties of the samples were tested by microcomputer controlled electronic testing machine,and the combustion properties of the samples were tested by infrared thermal imager,the data were analyzed and compared.The results show that increasing the curing agent can improve the tensile and compressive strength of the cured product,and the tensile strength of GAP after curing can be comparable to that of isocyanate-cured GAP.When the molar ratio of DDPM to GAP is 2:1 and 4:1,the tensile and compressive strength of the samples prepared by room temperature catalytic method are better;When the molar ratio of DDPM to GAP is 8:1,the tensile and compressive strength of the samples prepared by heating method are better,but the elasticity is poor.All three samples prepared by room temperature catalytic method can be ignited,while the samples prepared by heating method can be ignited only when the molar ratio of DDPM to GAP is 8:1.Compared with the normal temperature catalytic method,the combustion temperature of the sample cured by the heating method is lower,about 774℃,and the combustion residue is slightly more,about 4.5%.(4)The terephthalic acid(PTA)and Pelargonic acid vanillylamide(PAVA)were introduced into the uncured GAP by the heating method,and they were cured together(the molar ratio of DDPM and GAP was 8:1),the samples of GAP-PTA and GAP-PAVA systems were prepared.The compatibility of each component of the GAP-PTA system was analyzed by thermogravimetric/differential thermal analyzer,the combustion temperature of the two formulations in the GAP-PTA system was tested by an infrared thermal imager,and the morphology of GAP-PAVA was observed by a scanning electron microscope.The results showed that the cured GAP,PTA and AP contained in the GAPPTA formulation were compatible with each other,and the system had a certain stability.The two formulations of GAP-PTA system have an open fire after being ignited.After the open fire is blown out,it will emit smoke.The maximum temperature of open fire combustion not exceed 600℃,and the maximum temperature of smoke stage not exceed350℃.In the GAP-PAVA prepared by solution blending method,the sample morphology is fairly good when the PAVA content is 40%,and the PAVA is uniformly dispersed in the GAP matrix in the form of small needle-like crystals not larger than 5μm.When the PAVA content is 50%,there is no crystal precipitation on the surface of the sample,and PAVA is mainly dispersed in the GAP matrix as particles formed by agglomeration of needle-like crystals not larger than 5μm.Both of them can be ignited and continue to burn.