Study On Mechanical Properties Of Azide Polyether Elastomer

Azide polyether propellants have the advantage of high energy,low signature,etc.But due to the side chains of azide polyether containing a large amount of rigid groups,the propellant showed poor mechanical properties.In order to improve the mechanical properties of azide polyether propellants,the adhesive matrix should be considered first.In this paper,we used curing agent compound,chain extender,cross linkers and other methods,through introducing flexible chain and adjusting crosslinked network structure to regulate the microstructure of azide polyether elastomer,thereby improved the mechanical properties of azide polyether elastomer.The main results were as follows:(1)Using different types of isocyanate curing agents,studied the properties influence of R value and curing agent ratio to PBT elastomer.The results showed that: with the increase of the R value,the maximum tensile strength of the elastomer increase,the elongation decrease,the molecular weight between crosslinking points decrease,network crosslinking density increase.The structure parameters of the network formed by the elastomer has a very good linear relationship with the mechanical properties.In the composite curing system,with the increase of TDI or IPDI content,the tensile strength of the elastomer increased first and then decreased,the elongation at break increased;the N-100/TDI composite curing system exhibited superior mechanical properties compared with the N-100/IPDI system(2)With the increase of molecular weight of chain extender,the tensile strength of the elastomer reduced,the elongation at break increased first and then decreased.When using PEG200 as a chain extender,the mechanical properties of the elastomer was good,at this time tensile strength was 3.01 MPa,elongation at break was 573.90%.DSC and DMA test results showed that with the increase of molecular weight of chain extender,the glass transition temperature of the elastomer moved to lower temperature.(3)Compared to one-step method,the elastomer prepared by two-step method exhibited superior mechanical properties.Since it can formed more regular crosslinked network structure.(4)Using TEA or TMP as a crosslinking agent,after introducing cross-linked structure to the hard segment of the azide polyether elastomer,it will affected the microstructure of the elastomer.When the cross-linking agent content of TEA was 1.7 wt.%,it can formed a bimodal cross-linked network structure with appropriate proportion of long and short chains in the elastomer,then the elastomer with best mechanical properties was get.