硝酸酯增塑的热塑性聚氨酯弹性体推进剂

Nitrate ester plasticized thermoplastic polyurethane elastomers propellant

关键词:  热塑性  弹性体  聚氨酯推进剂  推进剂粘合剂  推进剂增塑剂  推进剂性能

Key words:  Thermoplasticity  Elastomer  Polyurethane propellant  Propellant binder  Propellant plasticizer  Propellant property

摘要:

研究了在热塑性聚氨酯弹性体 (TPU )软段中引入聚乙二醇 (PEG) ,以改善与硝酸酯的混溶能力。通过控制 PEG的相对分子质量和含量 ,可使硝酸酯与 TPU的混溶比大于 4。采用溶剂法挤压成型工艺成功地制成了硝酸酯增塑的 TPU推进剂。此类推进剂的理论比冲为 2 598N· s/kg～ 2 648N· s/kg,燃烧性能优良 ,空白配方的压力指数为 0 .36,常、低温力学性能优异 ,可为硝酸酯增塑 ,加工温度较低。该推进剂是一个可以实现以挤压工艺生产的复合推进剂新品种 ,具有良好的应用前景。此外 ,对推进剂的热分解性能也进行了研究

Abstract:

A novel thermoplastic polyurethane elastomer based on co polyether (ethyleneoxide tetrahydrofunan) as soft segments,isophorone diisocyanate and 1,4 butanediol as hard segments was synthesized It was used as propellant binder In order to increase the miscibilities of thermoplastic polyurethane elastomers with nitrate ester, polyethyleneglycol was incorporated with co polyether (ethyleneoxide tetrahydrofunan) as soft segments When the molecular weights and contents of polyethyleneglycol were controlled to 4000 and 6% of soft segments respectively, the properties of thermoplastic polyurethane elastomers were perfect The plasticizing ratio that nitrate ester to thermoplastic polyurethane elastomers exceeded 4 and no crystallinities were determined under room temperature The propellant sample was prepared by conventional absorption rolling extrusion process and the mechanical and combustion properties were evaluated The maximum impulse reached up to 2 598 N·s/kg~2 648 N·s/kg and was a little higher than HTPB propellant Measured results revealed that a promising TPE propellant candidates showed good processing temperature (<393 K) and excellent mechanical properties The burning rate pressure exponent reached as low as 0 36, which lends to a easy control in propellant combustion without the addition of burn rate catalysts