Fundamental Study on Organoclay Nanocomposites Based on Functionalized Block Copolymer, Functionalized Liquid-Crystalline Polymer, and Functionalized Polynorbornene

摘要：项目负责人：Chang D. Han单位：阿克伦大学项目编号：0406752研究方向：研究高剥离有机粘土纳米复合材料的基本原理和机理。端段为C官能团的二烯基abc型三嵌段共聚物将通过阴离子聚合和羟基化/氧化反应合成，通过缩聚聚合合成功能化热致液晶聚合物（TLCP），通过开环复分解聚合合成带有羟基、乙酸或胺基的功能化聚降冰片烯（PNB）。然后，将每种聚合物与化学改性的有机粘土或有机碳纳米颗粒通过微型双螺杆复合剂的熔融混合，生产出具有高度剥离性的纳米复合材料。二烯基端嵌段功能化的abc型三嵌段弹性体与传统的苯乙烯-丁二烯共聚物（SB橡胶）相比，其优势在于，通过合理控制abc型三嵌段共聚物中二烯嵌段的微观结构，可以通过非常高的剥离程度大大改善纳米复合材料的机械性能。基本前提是在有机粘土或有机碳纳米颗粒与聚合物基体之间提供有吸引力的相互作用：功能化abc型三嵌段共聚物，功能化TLCP或功能化PNB。吸引相互作用的存在将使用原位傅立叶变换红外光谱进行测试。将使用x射线衍射、透射电子显微镜和振荡剪切流变仪测试剥离程度，并研究纳米复合材料的力学性能（拉伸强度、撕裂强度、动态模量和冲击强度）。研究这些纳米复合材料的形成、结构和动力学可以更好地理解与获得高度剥落的有机粘土纳米复合材料相关的原理和机制，并有可能开发新型纳米复合材料。从这个研究项目中发展出来的基本概念将有助于其他研究人员通过设计和合成新的聚合物体系或合成新的表面活性剂来开发新的纳米复合材料，这些表面活性剂可用于修饰层状硅酸盐或石墨的表面。更广泛的影响：这些活动产生的更广泛的影响包括两个方面：(1)它将激励其他研究人员在可靠的科学基础上开发新一代的纳米复合材料；(2)它将有助于为美国聚合物制造工业开辟道路，生产新的具有吸引力和成本效益的新型纳米复合材料；(3)它将帮助价值400亿美元的美国轮胎制造业创新/改变现有的制造工艺，以提高轮胎的撕裂强度和滚动阻力。

ABSTRACTPI: Chang D. Han Institution: University of AkronProposal Number: 0406752Research: Fundamental issues concerning the principles and mechanisms associated with achieving a highly-exfoliated organoclay nanocomposite will be investigated. Diene-based ABC-type triblock copolymers with a functional group in the endblock C will be synthesized via anionic polymerization followed by hydroxylation/oxidation reactions, a functionalized thermotropic liquid-crystalline polymer (TLCP) will be synthesized via condensation polymerization, and functionalized polynorbornenes (PNB) with hydroxyl, acetic, or amine groups will be synthesized via ring opening metathesis polymerization. Then each of the polymers will be mixed, via melt blending using a micro twin-screw compounder, with chemically-modified organoclay or oganocardbon nanoparticles to produce nanocomposites with a high degree of exfoliation. Diene-based, endblock-functionalized ABC-type triblock elastomers have advantages over the conventional styrene-ran-butadiene copolymers (SB rubber) in that greatly improved mechanical properties, via a very high degree of exfoliation, of the nanocomposites can be obtained by judiciously controlling the microstructure of the diene block in an ABC-typle triblock copolymer. The basic premise is to provide attractive interactions between the organoclay or organocarbon nanoparticles and the polymer matrix: functionalized ABC-type triblock copolymer, functionalized TLCP, or functionalized PNB. The presence of attractive interactions will be tested using in-situ Fourier transform infrared spectroscopy. The degree of exfoliation will be tested using X-ray diffraction, transmission electron microscopy, and oscillatory shear rheometry, and the mechanical properties (tensile strength, tear strength, dynamic modulus, and impact strength) of the nanocomposites will be investigated. Investigation of the formation, structure, and dynamics of these nanocomposites can lead to a better understanding of the principles and mechanisms associated with achieving highly-exfoliated organoclay nanocomposites, and potentially to the development of novel nanocomposite materials.The fundamental concepts that will be developed from this research project should help other researchers to develop new nanocomposites either by designing and synthesizing new polymer systems or synthesizing new surfactants that can be used to modify the surfaces of layered silicates or graphite. Broader Impacts: The broader impacts resulting from these activities lie in two areas: (i) it will stimulate other researchers to develop new generations of nanocomposites on the basis of sound scientific foundations, (ii) it will help open avenues for the U.S. polymer fabrication industry to produce new attractive and cost-effective novel nanocomposites, and (iii) it will help the $40 billion U.S. tire manufacturing industry to innovate/alter the existing manufacturing processes for improved tear strength and rolling resistance of tires.