Preparation and Analysis of Thermal and Mechanical Properties of HTPB-type Polyurethane Elastomer Containing Paraffin Microcapsules

Two microcapsules with different paraffin phase changes were prepared using styrene-divinylbenzene copolymer and melamine resin as the capsule wall and paraffin(with a melting point of 50°C)as the capsule core.The microcapsules were directly added to the hydroxyl terminated polybutadiene(HTPB)-polyurethane elastomer system to fabricate the polyurethane elastomer composites.The thermodynamic stability and mechanical properties of the material were then studied.The results show that the thermal stability of the polyurethane elastomer does not decrease after adding paraffin phase change microcapsules,and the thermal stability of the polyurethane elastomer with melamine resin as the wall increases.Tensile strength increased from 367 kPa to 797 kPa,and compression strength increased from 245.9 N to 344.7 N.In addition,capsule walls comprised different monomers/paraffin microcapsules of the copolymer of styrene and divinylbenzene.The optimal mechanical property was obtained at a monomer/paraffin ratio of 1:1.The compression strength increased and the tensile strength decreased.The tensile strength of the microcapsule with melamine resin capsule wall and the compression strength of the microcapsule with polystyrene capsule wall were considerably improved.

温度对某型四组元丁羟推进剂热分解和热安全性能的影响

以60℃、65℃、70℃、80℃为起始温度,将推进剂置于DSC和TG试验仪中恒温两小时后直接升温进行DSC和TG试验,得到了该型推进剂各个温度下的热安全特征量和热分解参数。理论推导了表观活化能和温度的关系,并计算各个温度下该型推进剂的表观活化能E,线性拟合了表观活化能与温度的关系式。研究表明在60~80℃的温度,该型推进剂的表观活化能与温度呈线性关系。