纤维素甘油醚硝酸酯粘合剂及其推进剂的力学性能

利用X-ray衍射、拉伸实验和动态力学性能DMA实验研究了纤维素甘油醚硝酸酯(NGEC)的结晶度、NGEC及其推进剂的力学性能和动态力学性能,借助扫描电镜观察了NGEC基改性双基推进剂的断裂形貌,并通过流动性实验探索了NGEC全部与部分取代NC的改性双基推进剂的热加工工艺性能。结果表明:与NC相比,NGEC的结晶度和力学强度略低、延伸率较高、玻璃化转变温度低且转变温度范围宽;加入NGEC,可降低高固体含量改性双基推进剂的脱湿现象,有利于提高其力学性能;粘合剂体系中NGEC的含量对其改性双基推进剂的玻璃化转变的α松弛影响较大,随着NGEC含量的增加α松弛温度明显降低,而对β松弛的影响较小;与NC相比,NGEC的加入降低了改性双基推进剂的流动性实验出药压力,提高了出药速度,具有良好的热塑性及热加工安全性。

Study on the mechanical properties of NGEC and NGEC based propellants

The crystallinity of Nitrate cellulose glycerol ether(NGEC),the mechanical and dynamic mechanical properties of NGEC and NGEC based propellants were studied by using X-ray diffraction,tensile test and dynamic mechanical analyzer.The tensile fracture surface of NGEC based propellants was observed by scanning electronic microscopy,and the thermal processing properties of NGEC based propellants were investigated by fluidity experiment.It is shown that,compared with NC,the crystallinity and the mechanical strength of NGEC are lower,the elongation is higher,the glass transition temperature is lower and the range of transition temperature is wider.The dewetting of particles was decreased and the mechanical properties were improved for the modified double base propellant added with NGEC.The effect of the content of NGEC on the α-relaxation of NGEC based propellants glass transition are greater,and the α-relaxation temperature was decreased significantly with increasing of NGEC,but the influence of NGEC content on the β-relaxation was less.The NGEC based propellants have good thermoplastic and hot process properties with lower pressure and high speed of pressing-propellant.