HTPB 热稳定性研究

STUDY OF THERMAL STABILITY OF HYDROXYL TERMINATED POLYBUTADIENE

关键词:  端羟基聚丁二烯  推进剂粘合剂  推进剂防老剂  热反应  热分析

Key words:  Hydroxyl terminated polybutadiene +  Propellant binder  Propellant antioxidant  Thermal reaction  Thermal analysis.

摘要:

通过热重分析法（ＴＧ）、差动热分析法（ＤＳＣ）和红外光谱分析法（ＩＲ），研究了环境气氛和氮气气氛下端羟基聚丁二烯（ＨＴＰＢ）热氧化反应动力学和反应机理，应用ＤＳＣ测定了环境气氛下ＨＴＰＢ的氧化反应峰峰温，求得了ＨＴＰＢ氧化反应表观活化能Ｅ，指前因子Ａ，反应速率常数ＫＴ。运用Ｄｏｌｙｅ公式求出了氧化反应诱导期ｔｉ，由此确定防老剂Ｈ和抗氧剂Ａｔ－２１５的最佳含量，Ａｔ－２１５对ＨＴＰＢ的防老化作用优于防老剂Ｈ。实验表明：环境气氛下１６０°Ｃ～２５０°Ｃ温度范围内ＤＳＣ曲线上的第一个放热峰以及ＴＧ曲线上对应的增重部分是由于环境气氛中的氧加入到ＨＴＰＢ骨架上所致；随着温度的升高，碳碳双键（１６３７ｃｍ－１）伸缩吸收峰逐渐减弱，同时羰基（１６９４ｃｍ－１）吸收峰和羟基（３３３０ｃｍ－１）吸收峰逐渐增强；ＫＴ与ｔｉ可以表征防老剂的防老化效果。

Abstract:

Kinetic and mechanism of thermal oxidative reaction for Hydroxyl Terminated Polybutadiene(HTPB)had been studied by TG,DSC,IR in air and nitrogen.Based on the peak temperature oxidation reaction of HTPB in air determined by DSC,the apparent activation energy(E),frequency factor(A)and reaction rate constant ( K T)were obtained.The oxidative reaction induction time( t i) was calculated with Doyle equation,then the contents of two antioxidants(H and At 215)for HTPB were evaluated.The experimental results indicated that the first exothermic peak of DSC curve and the mass gain step of TG curve in the range of 160°C～250°C in ambient air were due to the addition of atmospheric oxygen to polybutadiene backbone.With the increase of temperature,the absorption intensity of C=O(1694cm -1 )and-OH(3330cm -1 )increased while the absorption peak of C=C double bonds(1637cm -1 )decreased.The efficiencies of the antioxidants could be characterized by K T and t i.