【作者】 刘勇；

【导师】 聂仪晶；

【作者基本信息】 江苏大学 ， 材料工程（专业学位）， 2020， 硕士

【摘要】 为了解决传统的橡胶填料补强体系所伴生的缺陷和为延长橡胶制品的使用寿命提供新的思路和解决方案,针对新型橡胶补强填料和对具有自修复行为的橡胶材料的开发和研究具有重要意义。在能源危机问题日益突出的背景下,作为最具代表性的可再生资源,天然橡胶（NR）和其衍生物环氧化天然橡胶（ENR）的研究表现出极高的开发潜力。本论文围绕解决橡胶材料补强体系的缺陷和通过引入自修复机制实现橡胶材料使用的寿命延长进行系统的研究。具体包括以下几个方面:1.纳米二氧化硅（NanoSiO₂）和氧化石墨烯（GO）通过共价连接方式得到的杂化填料对NR基体的补强及增韧。首次将两种不同维度的纳米填料共价连接得到的杂化填料应用到NR的补强研究中,采用实验与蒙特卡洛（MC）计算机模拟相结合的方法对其补强和增韧的机制进行研究。研究发现共价连接的处理方式显著提高了纳米填料在橡胶中的分散性,相比单种纳米填料填充的NR,使用同样填充量的杂化填料增强样品拥有最高的交联密度进而表现出最佳的补强效果,同时没有伴随着断裂伸长率的显著下降。MC模拟结果进一步证明,杂化填料相比单一的纳米材料具有更强的诱导界面区域链取向的能力,通过促进界面区域发生应变诱导结晶实现对NR的补强和增韧。2.将二甲基丙烯酸锌（ZDMA）的离子簇的缔合-解离作为自修复功能的实现途径对ENR向自修复材料转变进行探索和研究。以ENR为基体尝试ENR/ZDMA体系自修复材料的制备,同时采用轻度共价交联与离子交联网络共存的方式提高复合材料体系的强度和稳定性。研究发现ZDMA作为自修复机制在引入ENR基体实现自修复功能是可行的,并探究在两种不同环氧化程度的ENR（25%和40%,记为ENR25和ENR40）基体中引入ZDMA实现自修复功能的效果。结果表明ENR40/ZDMA体系在80°C的温度条件下修复1 h后实现80%以上的拉伸强度恢复;在30°C下修复50 min后,ENR25/ZDMA复合材料的机械性能得到约70%的恢复。3.将合成路线中接枝了2-氨基-4-羟基-6-甲基嘧啶（UPy）基团的聚氨酯（PU-UPy）作为四重氢键的引入机制与ENR混合得到具有自修复功能的ENR/PU-UPy共混材料,同时在自修复材料设计中引进了轻度的共价键交联网络以保持材料的强度和稳定性。对共混材料体系进行DMA测试发现ENR和PU-UPy表现出极好的相容性,并且30 wt.%PU-UPy的添加量对ENR的动态机械性能影响基本到达最大值。研究PU-UPy材料和ENR/PU-UPy体系的自修复能力,结果表明填充了30 wt.%PU-UPy的共混材料在60^oC环境条件下修复50 min后,其机械性能指标得到超过80%的恢复,因此将PU-UPy作为氢键网络的引入介质以实现ENR向自修复材料的转变是可行的。更多还原

【Abstract】 In order to solve the defects associated with the traditional rubber filler reinforcement system and provide new ideas and solutions for extending the service life of rubber products,it is of great significance to develop and research new rubber reinforcement fillers and selfrepairing rubber materials.In the context of the increasingly prominent energy crisis,as the most representative renewable resource,research on natural rubber(NR)and its derivatives,epoxidized natural rubber(ENR),has shown great development potential.This thesis focuses on solving the defects of the rubber material reinforcement system and introducing selfrepairing mechanisms to extend the life of rubber materials.The main research contents are given as follows:1.Preparation of the hybrid filler by covalent bonding of nanosilica(nanoSiO2)and graphene oxide(GO)and study on the enhancement effect of the hybrid filler on NR.Through the combination of experiments and Monte Carlo(MC)computer simulation methods,the mechanism of strengthening and toughening of hybrid fillers was studied.It is found that the dispersibility of the treated nanofillers in rubber has been significantly improved.Compared with NR filled with untreated nanofillers,NR filled with the hybrid filler with the same filling amount has the highest crosslinking density and therefore shows the best reinforcement effect,and no significant reduction in elongation at break has been discovered.The MC simulation results further demonstrate that the hybrid filler has a stronger ability to induce chain orientation than GO or nanoSiO2,and it can enhance and toughen NR by promoting strain-induced crystallization in the interface region.2.The association-dissociation of the ion clusters of zinc di-methacrylate(ZDMA)is used as a mechanism to realize the self-repairing function of ENR.ENR was used as a matrix to try to prepare self-healing materials.At the same time,the design of slight covalent cross-linking and ionic cross-linking networks is used to improve the strength and stability of the composite system.The self-repairing effects of introducing ZDMA into the self-repairing function of ENR matrix with two different degrees of epoxidation of 25% and 40% have been investigated.It is found that ZDMA as a self-repairing mechanism is feasible in the introduction of ENR matrix to achieve self-repairing function.The ENR40/ZDMA system can recover more than 80% of the tensile strength after 1 h at 80°C;After 50 minutes of recovery at 30°C,the mechanical properties of ENR25/ ZDMA composites were recovered by approximately 70%.3.In the polyurethane(PU)synthetic route,a 2-amino-4-hydroxy-6-methylpyrimidine(UPy)group is grafted and a carbon-carbon double bond is introduced to obtain PU-UPy.PUUPy is then mixed with ENR as a component carrying multiple hydrogen bonding structures to complete the design of the ENR/PU-UPy blend material with self-repairing function.At the same time,a slightly covalent cross-linking network is introduced into the design of self-healing materials to maintain the strength and stability of the ENR/PU-UPy.It is found that Both PUUPy and ENR/PU-UPy blends exhibit excellent self-repairing properties.In particular,the performance of ENR/PU-UPy filled with 30 wt.% of PU-UPy can be restored to more than 80% of the original sample after 50 minutes repair at 60°C.Therefore,it is feasible to use PU-UPy as the introduction medium of multiple hydrogen bonding networks,and it can realize the transition from ENR to self-repairing materials.更多还原