Polytetrahydrofuran (PTHF) is a candidate binder ingredient to improve the burning performance of composite propellant because PTHF has one oxygen atom in the repeating unit. The molecular structure of PTHF is similar to that of HTPB. Therefore, PTHF would be easily blended with HTPB and a homogenous blend would be prepared. PTHF is commercially produced in several different molecular weights. It would be expected that the mechanical properties and burning characteristics of composite propellants would be controlled by molecular weight of PTHF and PTHF/HTPB mass ratio when PTHF/HTPB blend would be used as a binder. The curing behavior, the tensile property, and the thermal decomposition characteristics of PTHF/HTPB blends were investigated in this study. The molecular weights of PTHFs were 650, 1400, and 2900. The curing behavior and tensile property depended on molecular weight of PTHF and PTHF/ HTPB mass ratio. The temperature range of the main thermal decomposition of the PTHF/HTPB blends was lower compared with that of HTPB alone.
ポリテトラヒドロフラン（PTHF）は繰り返し単位中に酸素を含むため, HTPBと比較して酸素含有量が多く, 推進薬 の燃焼性向上を期待できる。PTHFの構造はHTPBのそれと似ているため, HTPBとの混和が可能であり, 均質なブレン ドを調製できると考えられる。また, さまざまな分子量のPTHFが市販され, 安価に入手できる。PTHF/HTPBブレン ドを推進薬バインダとして用いた場合, PTHFの分子量とブレンド中のPTHF含有率を変化させることによって, 推進薬 の機械的特性や燃焼特性を調節できると考えられる。本実験では, 分子量650, 1400, 2900のPTHFを用いたPTHF/HTPB ブレンドの硬化特性，引張り特性及び熱分解性について調べた。硬化特性や引張り特性は, PTHFの分子量とPTHF含有 率に依存した。ブレンドの主熱分解の温度範囲は, HTPB単独のものより低温側へシフトした。
Polytetrahydrofuran, Hydroxyl Terminated Polybutadiene, Propellant Binder,
Tensile Property, Thermal Decomposition