宽温域高阻尼多机制协同减振橡胶复合材料的设计、制备及性能研究

Chlorinated butyl rubber is a kind of common damping material, but it has the defects such as not-wide damping temperature ranges at high temperatures, poor damping stability at low temperatures, and the damping and heat resistant properties cannot meet actual requirements. These defects may be overcome by dendrimer modification technology. With structure design of dendrimers, the high and low damping temperature ranges may be simultaneously expanded and the damping and heat resisatant properties may be effectively improved by combination of silicate layers having slice constraints, hindered phenol having hydrogen bonds, and dendritic polysiloxane having entanglement and buffering characteristics together with high and low temperature resistance. The key point of this technology is its precise design of structural parameters, multi-components ingenious assembly, and controllable propagation of dendrimers.In this project, organic montmorillonite was prepared by the intercalation agent having high temperature resistance.Then, hydrogen-containing dendritic organic montmorillonite was prepared on the basis of siloxane branching units. Last, dendritic damping agent was prepared by further grafting of hindered phenol. The influence of interlayer spacing of montmorillonite, porosity of dendrimers, content of hydroxyl groups in hindered phenol on the damping properties and temperature ranges of the composite were analyzed to realize its controllable regulation. The “structure-effect” relationship between the structure of different stages and the performance of the damping rubber composite was researched and its damping mechanism was analyzed. Thus, the theoretical basis for its further application was established.

氯化丁基橡胶是一类常见的阻尼材料，但存在高温阻尼温域不宽、低温阻尼稳定性不佳、阻尼及耐热性能不能满足实际要求等缺陷。利用树枝形聚合物改性技术有望克服上述缺陷。通过树枝形聚合物的结构设计，将片层约束提高阻尼性能的层状硅酸盐、形成氢键达到阻尼效果的受阻酚以及具有缠结缓冲、既耐高温又耐低温的树枝形聚硅氧烷三者结合，实现橡胶复合材料高低阻尼温域的同时拓展、阻尼及耐热性能的有效提升。该技术的关键是树枝形聚合物结构的精确设计、多组分巧妙组装以及分子链的可控增长。本项目拟采用高耐热有机插层剂制备有机蒙脱土，在此基础上采用硅氧烷支化单元制备含氢树枝形有机蒙脱土，进一步接枝受阻酚制备树枝形阻尼剂。分析树枝形阻尼剂中蒙脱土的层间距、树枝形聚合物的孔隙率、受阻酚中羟基含量对复合材料阻尼性能及阻尼温域的影响规律，实现可控调节。研究各级结构与阻尼橡胶性能之间的“构-效”关系，揭示阻尼机制，为其推广应用奠定理论基础。

本项目面向制备阻尼材料的关键科学问题，以氯化丁基橡胶(CIIR)为研究对象，开展温域宽广、阻尼高效、调控灵活的新型阻尼剂研制及其阻尼减振性能与机制研究。采用无机蒙脱土、有机改性蒙脱土、改性受阻酚、树枝形聚合物以及树枝形阻尼剂等各级结构分别加入CIIR 基体中，制备阻尼橡胶复合材料。分析不同结构复合材料的阻尼温域、阻尼因子及损耗模量。系统研究各级结构与复合材料阻尼温域及阻尼性能之间的“构-效”关系，揭示内在规律及协同机制，为新型阻尼剂的开发及阻尼橡胶材料的制备提供科学依据。结果表明：①蒙脱土等粘土填料通过片层约束机制消耗外界机械能。其中，添加5份有机改性蒙脱土时，复合材料的阻尼因子tanδmax达到1.47，与纯CIIR的1.06相比提高了38.6％；有效阻尼温域（tanδ>0.7）向高温方向移动且接近常温。②改性受阻酚通过氢键作用机制消耗外界机械能。其中，添加20份改性受阻酚，复合材料tanδmax达到1.32，相比于空白样的0.92提高了43%；有效阻尼温域从空白样的40℃提高到添加20份的75.6℃，提高了89%。③树枝形阻尼剂通过多孔网络结构的强迫互容、界面互穿的缠结缓冲机制将机械能转化为热能。其中，添加5份树枝形阻尼剂的tanδmax增加到1.52，与纯CIIR的1.08相比提高了41%；对应tanδ>0.55的阻尼温域达到140℃(-43~97℃)，相比纯CIIR(64℃，-44~20℃)提高了119%。总之，经阻尼改性的CIIR橡胶复合材料的阻尼损耗因子得到提高、有效阻尼温域得到拓展且向高温区移动，有利于阻尼橡胶材料的实际工程应用。