推进剂中新型聚醚聚氨酯粘合剂的热分解行为

THERMAL DEGRADATION OF SOME NOVEL POLYETHER URETHANES IN PROPELLANT

关键词:  聚氨酯推进剂  聚醚推进剂  推进剂粘合剂  热分解  热分析

Key words:  Polyurethane propellant  Polyether propellant  Propellant binder  Thermal decomposition  Thermal analysis

摘要:

采用ＳＤＣ和ＴＧ两种热分析方法研究了推进剂中两种新型聚醚粘合剂及经不同增塑剂增塑后的聚氨酯弹性的热分解行为。研究表明环氧乙烷／四氢呋喃共聚醚具有较好的热稳定性， 热分解大约从２２０°Ｃ开始； 用Ｎ－１００ 固化和加入抗氧剂均能显著提高其稳定性。聚氨酯弹性体的热失重分阶段进行， 首先是增塑剂的挥发和分解， 然后是聚氨酯网络的裂解。以聚乙二醇（ＰＥＧ）为聚醚二元醇的聚氨酯比共聚醚聚氨酯具有较低的热稳定性， 但经硝酸酯增塑后，ＰＥＧ体系比共聚醚体系表现出较高的稳定性。

Abstract:

The thermal degradation behavior of some novel polyether urethanes in propellant was investigated with Thermogravimetry(TG)and Differential Scanning Calorimetry(DSC).The effect of glycol structure,antioxidant and centralite was also involved.EO/THF co polyether showes that there is no obvious weight loss below 220 °C.Its stability can be significantly improved by curing with N 100 or adding antioxidant.The weight loss of polyether urethanes cured by N 100 proceeded in two stages,first the volatilization and decomposition of plasticizer,then the pyrolysis of the polyurethane network.Using EO/THF co polyether as soft segment instead of PEG reduced the decomposition activation energy as well as the decomposition enthalpy of nitrate esters,but improved the stability of polyurethane network.Antioxidant and centralite decreased the decomposition enthalpy of nitrate esters while increased the stability of both nitrate esters and polyurethane network.