【作者】 李凡；

【导师】 叶林；

【作者基本信息】 四川大学 ， 材料学， 2007， 硕士

【摘要】 高聚物粘结炸药（PBX）是目前广泛使用的一类复合炸药，TATB（1，3，5-三氨基-2，4，6-三硝基苯）是一种钝感、高能单质炸药，以TATB为基的PBX应用十分广泛。但由于其极强的分子内和分子间氢键作用，使其表面能很低，难于粘结。氟聚物是通常用于TATB基PBX的粘结剂，其分子间凝聚力低，表面自由能极低，难于被液体或固体浸润或粘着，严重影响其与填料、或其它聚合物间的界面相容性及其共混复合材料的性能。本文研究制备了含硼偶联剂以提高氟聚物／TATB界面作用和粘合强度；另一方面，对热塑性聚氨酯弹性体（TPU）合成、分子结构参数对其力学性能、阻尼性能影响规律性进行研究，获得了具有优异力学性能、阻尼性能和粘结性能，适于PBX的高性能粘结剂，有效提高了PBX的机械性能，降低感度，提高其安定性。通过分子设计，研究制备了一系列含硼偶联剂，利用硼原子与含氟聚合物中氟原子形成良好的配位键作用，并在偶联剂分子中引入与TATB相似或有键合作用的基团，达到分子桥的连接作用，以期提高氟聚物／TATB复合材料的界面作用。通过接触角测定，计算了经偶联剂改性前后氟聚物与TATB的界面张力和粘附功，用FTIR、XPS和SEM对偶联剂的界面作用进行了分析，并用巴西实验测试了TATB基PBX的机械性能。结果表明，含硼偶联剂能够降低TATB与氟聚物之间的界面张力，提高粘附功。偶联剂对炸药本体没有破坏，偶联剂中的胺基可与TATB中的硝基形成氢键作用。偶联剂CA-4可以提高TATB基PBX的力学性能。TPU与氟聚物相比，具有优异的力学性能、阻尼性能及粘结性能，是PBX体系的高性能粘结剂。本文通过改变TPU分子的结构参数（分子量，异氰酸酯种类，硬段含量，软段种类，软段分子量，扩链剂种类），用本体聚合一步法合成了一系列TPU，并分析了其力学性能及动态力学性能，结果表明，TPU选用MDI和PBA作为软硬段具有较好的综合性能，增加硬段质量分数可以增加TPU的硬度，降低断裂伸长率，阻尼峰向高温方向移动；增加软段分子量可以增加热塑性聚氨酯弹性体的拉伸强度、硬度，降低断裂伸长率，并使阻尼值降低，阻尼峰向低温方向移动；增加扩链剂长度，拉伸强度和硬度依次降低，断裂伸长率上升，阻尼性能上升，增加扩链剂侧基可以增加阻尼性能。用FTIR、GPC和AFM分析了TPU的分子结构、微相结构，分子量及其分布，结果表明，合成的TPU分子量高，分子量分布窄，性能稳定，在TPU的分子中，存在微相分离，硬段相均匀分布于软段相之中，起到增强作用。将所合成的TPU（CMA-14）对炸药进行包覆，研究了其与炸药之间的界面张力和粘附功，并用含硼偶联剂和钛酸酯偶联剂进行表面处理，结果表明，CMA-14与TATB和HMX的界面张力小于F₂₃₁₄，粘附功要大于F₂₃₁₄，具有较好的粘结性能，含硼偶联剂和钛酸酯偶联剂可进一步提高TPU与TATB之间的界面性能，提高粘附功。将包覆好的PBX造型粉进行机械感度测试，并采用压缩强度与巴西实验测试了PBX力学性能，采用SEM分析了CMA-14的包覆效果。结果表明，CMA-14包覆的PBX的压缩强度，模量，巴西实验破坏强度，压缩应变均要高于F₂₃₁₄，具有较好的机械性能。CMA-14包覆的PBX具有较低的感度，其撞击感度和摩擦感度值分别为76％和28％。CMA-14包覆TATB颗粒包覆完全，表面平整，无晶粒外露，包覆效果比F₂₃₁₄好。更多还原

【Abstract】 Polymer Bonded Explosive （PBX） is one of the widely used composite explosive at present, and Triamino-trinitro-benzene （TATB） is a kind of insensitive single-component explosive with high energy, which is applied in PBX commonly. There are very strong intramolecular and intermolecular hydrogen bonds in TATB molecules, resulting in the very low surface energy and poor adhesive performance. Fluoropolymers, which is often applied as bonding materials in TATB-based PBX, have low intermolecular cohesion force, and very low surface tension, which leads to very poor compatibility with other materials. In this work, the synthesis of coupling agents and thermoplastic polyurethane elastomer （TPU） were studied for the interfacial modification of PBX composite, in order to improve the interfacial bonding of explosives and polymers, and enhance the mechanical property of PBX, reduce its sensitivity, and obtain polymer bonding materials with high performance adapting to PBX.Through molecular design, a series of boron-containing coupling agents were synthesized, which were applied to improve the interfacial bonding of fluoropolymer/TATB composite. The boron atom of the coupling agent molecule can form coordinate bond with the fluorine atom of fluoropolymer; and hydrogen atom in its amino group can form hydrogen bond with oxygen atom in nitro-group of TATB. The interfacial performance of the composite was investigated by the measurement of contact angle, surface and interface tension, and adhesive work, and the interfacial bonding mechanism were studied by FTIR, XPS and SEM analysis, and the mechanical property of TATB- based PBX was studied by brazilian test. The results showed that the interfacial tension decreased, the adhesive work increased, and the interfacial bonding was improved remarkably for the composite through being modified by the coupling agents. There was no influence on the chemical stability of TATB when modified with the coupling agents, and the strong hydrogen bond between amino-group of the coupling agents and nitro-group of TATB, and coordination bond between boric atom of the coupling agents and fluorine atom of fluoropolymer were formed. The fluoropolymer/TATB composite modified by CA-4 showed relatively higher mechanical property.Compared with fluoropolymer, TPU has excellent mechanical property, damping property and adhesive property, which play an important role in PBX system as adhesive. A series of polyester-based thermoplastic polyurethanes elastomer（TPU）, with different kinds of molecular structure parameter （molecule weight, diisocyanate, hard segment content, soft segment, molecular weight of the soft segment, chain-extending agent）, were prepared through bulk synthesis and one-step process. The effects of structure parameter on the mechanic properties and dynamic viscoelasticity of TPU were investigated. The results showed that TPUs using PBA as soft segment and MDI as the diisocyanate had excellent mechanical property, and tensile strength of which reached about 30 MPa. The hardness and the glass transition temperature of polyester-base TPUs were improved and the elongation at break was reduced by increasing mass fraction of hard segment; The tensile strength, hardness and the glass transition temperature of polyester-base TPUs were increased, elongation at break was reduced and the peak temperature of damping factor moved toward low temperature region by increasing the relative molecular mass of soft segment; The tensile strength, hardness were reduced, the elongation at break and the value of damping factor were increased by increasing the length of chain-extending agent, and the damping property was increased by grafting side-chain at the molecule of chain-extending agent. The molecule structure, micro-phase structure, molecule weight and distribution were studied by FTIR, XPS and SEM analysis. The results showed that TPU had high molecule weight with narrow distribution and chemical stability. And there was micro-phase separation in TPU molecule, in which hard segment phase well dispersed in soft segment phase, which can display reinforcing effect on TPU.The synthesized TPU （CMA-14） was used to compound with explosives, and the interfacial tension and adhesive work were studied between explosives and CMA-14 before or after modified by boron-containing coupling agents and titanate coupling agents. The results showed that the interfacial tensions between CMA-14 and explosives were lower than F₂₃₁₄ and explosives, and adhesive works were higher, which indicated better adhesive property, and boron-containing coupling agents and titanate coupling agents can improve the interfacial interaction between TPU and TATB. The mechanical sensitivity of PBX compounded by CMA-14 was tested, and its mechanical property was tested by compression experiment, brazilian test and SEM. The results showed that the impact sensitivity and friction sensitivity of PBX compounded by CMA-14 were decreased, and the compression strength, modulus, breaking strength and compressive strain were all higher than that of F₂₃₁₄. The PBX molding powder was coated by CMA-14 better than F₂₃₁₄, and had smooth surface with litter TATB particles outside.更多还原