含叠氮基和硝基新型增塑剂的设计、合成与性能

Design,synthesis and properties of two novel plasticizers with azido and nitro

针对具有出色玻璃化转变温度(Tg=-101℃)的含能增塑剂DNPH(2,2-二硝基丙基正己酸酯)生成焓(-702 kJ·mol^(-1))偏低的问题,通过在分子结构中引入叠氮基团的方法,设计、合成了单叠氮基的DNPAH(2,2-二硝基丙基-6-叠氮基己酸酯)和双叠氮基的DNPDAH(2,2-二硝基丙基-5,6-二叠氮基己酸酯)。通过1H-NMR、FTIR及EA等结构解析技术确定了两种全新化合物的分子结构。与DNPH的生成焓相比,DNPAH(-417.8 kJ·mol^(-1))和DNPDAH(-113.4 kJ·mol^(-1))分别提高了40.5%、83.9%。表明,在增塑剂结构中引入叠氮基可显著提高其生成焓。另外,二者的Tg分别为-99、-80℃。DNPAH热稳定性好、机械钝感、挥发性及迁移性低。分子动力学(MD)模拟及实验研究表明,DNPAH与PBT(3,3-双(叠氮甲基)氧杂环丁烷-四氢呋喃共聚醚)相容性较好。在相同增塑比时,与PBT常用增塑剂BDNPF/A(双(2,2-二硝基丙基)缩甲/乙醛)及BuNENA(N-丁基硝氧乙基硝胺)相比,DNPAH增塑的Tg更低,尤其是当增塑比为2∶1时,低至-88℃。DNPAH有望作为PBT基推进剂用新型含能增塑剂。

In terms of the outstanding glass transition temperature(Tg=-101℃)but unfavorable enthalpy of formation(-702 kJ·mol^(-1))of the energetic plasticizer DNPH(2,2-dinitropropylhexanoate),monoazido DNPAH(2,2-dinitropropyl-6-azidohex-anoate)and diazido DNPDAH(2,2-dinitropropyl-5,6-diazidohexanoate)were designed and synthesized.Their novel structures were thoroughly characterized by 1H-NMR,FTIR and EA.Compared with the parent DNPH,the enthalpies of formation for DN-PAH(-417.8 kJ·mol^(-1))and DNPDAH(-113.4 kJ·mol^(-1))were impressively improved by 40.5%and 83.9%,respectively.It reveals that the plasticizer energy could be significantly increased by introducing the azido group.What’s more,Tg for DNPAH and DNPDAH are-99℃and-80℃.In addition,the low mobile DNPAH is insensitive to thermal and mechanical stimulus as well as low volatility.The favorable compatibility between DNPAH and PBT(3,3-bis(azidomethyl)oxetane tetrahydrofuran copolyether)is confirmed by molecular dynamic(MD)simulation and experimental study.With the same plasticizing ratio,Tg of the PBT and DN-PAH blend is even lower than that of the established binary mixture with BDNPF/A(bis(2,2-dinitroproponyl)formal/acetal)or BuNENA(N-butylnitroxyethylnitramine)as a plasticizer.It should be noted that when the plasticizing ratio is 2∶1,Tg of the blend is lower to be up to-88℃.DNPAH could be used as an energetic plasticizer for the PBT-based propellant.