Synthesis Of Multi-hydroxyl Polyether And Its Effect On Mechanical Properties Of High-Energy Nitramine Gun Propellant

In order to improve the mechanical properties of nitramine gun propellant,this paper adopted the polyethylene glycol(PEG)with different molecular weight and epichlorohydrin(ECH)as raw materials,to synthesize multi-hydroxy polyether with different number average molecular weight under the effect of alkaline catalyst.And with the synthesis of hydroxy polyether as a kind of nitramine propellant(RP5)tablets material toughening agent,toughening agent half solvent method was used to suppress the single-hole tubular nitramine propellant sample of the mass fraction of 1%,2% and 3% respectively.The pendulum impact testing machine and the drop hammer impact tester were used to test the radial and axial impact strength of nitramine propellant samples respectively,and universal testing machine was used to test the compression resistance of the samples.At the same time,the toughening RP5 tablets with the low degree of polymerization of GAP were used as the substrates,which were compressed into different toughening agent content of single-hole tubular specimen of nitramine propellants.Then,mechanical properties of the single-hole tubular specimen of nitramine propellant were tested and compered with agents that have good mechanical properties and polyether-2 toughening.In this paper,the main results were as follows:Because nitramine gun propellant can be molded by extrusion,nitrocellulose macromolecular chains will form partially oriention structure and it will make the difference between radial and axial impact resistance in the same samples.To a certain degaree,different number average molecular weight of hydroxyl polyether can improve the shock resistance and compression resistance of nitramine propellant samples,but with the increase of polyether number average molecular weight,the toughening effect is not obvious.Under low temperature(-40℃),the number-average molecular weight of polyether is 5618,adding amount is 3%,the compressive performance of sample promotion effect is better,the compression strength is two times than less flexibilizer sample;the number-average molecular weight of polyether is 5618,adding amount is 3%,the sample of the radial impact resistant performance is better,and increases by 53% compered with less flexibilizer sample;number-average molecular weight of polyether is 2118,adding amount is 3%,the sample of the axial toughening effect is better.The low degree of polymerization of GAP toughening sample can,to a certain extent,improve the mechanical properties of nitramine propellant,but the effect is not obvious when the amount of GAP is more.Under the low temperature(-40℃),the GAP amount is 1% when the system has a better comprehensive mechanical properties,the shock resistance and compression resistance than flexibilizer sample increased by 33% and 33% respectively;Under the situation that other conditions is same,when the compressing speed increases from 1 mm/min to 10 mm/min,the compression strength of agents with polyether and GAP as toughening agent all increase.The contrast experiment shows that the ascension of the mechanical properties of nitramine propellant samples with hydroxyl polyether-2(nM = 5618)as toughening agent is better than a sample containing GAP.