PBT基钝感低特征信号推进剂的力学性能优化研究

Research on mechanical properties optimization of PBT⁃based insensitive low signature solid propellant

采用单轴拉伸法和DSC法,研究了增塑比、扩链剂(BDO、PET、PEG)、交联剂(TN⁃J、TMP、PTT、T⁃PEG)对PBT/NENA/I⁃RDX(钝化RDX)/AP低Al体系钝感低特征信号推进剂力学性能和玻璃化转变温度的影响。结果表明,大分子扩链剂PEG可显著提高推进剂的最大伸长率,而抗拉强度基本不变;交联剂提高推进剂抗拉强度的作用大小依次为TN⁃J>TMP>PTT>T⁃PEG,其中TN⁃J可同时发挥键合作用,提高最大伸长率。当增塑比为2.0、综合调节TN⁃J和PEG的含量,推进剂20℃抗拉强度0.9~1.3 MPa、最大伸长率40%~70%,70℃抗拉强度0.6~0.7 MPa、最大伸长率30%~50%,-55℃最大抗拉强度3.7~4.6 MPa、最大伸长率45%~75%,玻璃化转变温度<-65℃,推进剂在-55~70℃时具有良好的力学性能,可满足工程化应用的需求。

Uniaxial stretching method and Differential Scanning Calorimetry(DSC)were used to investigate the influence of plasticization ratio,chain extender(BDO,PET,PEG)and cross⁃linking agent on the mechanical properties and Tg of PBT/NENA/I⁃RDX(Insensitive⁃RDX)/AP insensitive low signature solid propellant.The results show that the macromolecular cross⁃linking a⁃gent apparently improve the maximum elongation with little loss of tensile strength.In aspects of improving the tensile strength,the cross⁃linking agents in turns are TN⁃J>TMP>PTT>T⁃PEG.The TN⁃J acted as a bonding agent is beneficial to improve the maximum elongation.When the plasticization ratio is 2.0 together with a comprehensive adjustment of the content of TN⁃J and PEG,the ten⁃sile strength of PBT⁃based propellant at 20℃,70℃and-55℃is 0.9~1.3 MPa,0.6~0.7 MPa,3.7~4.6 MPa,respectively,and the maximum elongation is 40%~70%,30%~50%,45%~75%,respectively,accompanying with a Tg lower than-65℃and an excellent mechanical properties at-55~70℃,where requirements in the practical engineering applications can be met.