【作者】 赵明；

【导师】 李树新； 陈宏；

【作者基本信息】 北京石油化工学院 ， 化学工程（专业学位）， 2022， 硕士

【摘要】 目前,部分商业应用橡胶材料在加工和使用过程中易受机械损伤,最终无法重复使用,这造成了大量的资源浪费和环境的破坏。因此,为避免上述情况发生,本论文将可逆交联结构引入到橡胶的交联网络中,使其借助可逆化学键的作用自动修复自身损伤,有效延长使用寿命。本文首先以天然橡胶(NR)和丁基橡胶(IIR)为主要橡胶组分,二甲基丙烯酸锌(ZDMA)为离子键或离子簇的提供者,通过控制硫化过程,将ZDMA接枝聚合到橡胶分子链上,形成了由共价交联、离子交联和物理缠结构成的可逆超分子网络。实验表明,在室温下仅30 min的愈合时间内,NR/ZDMA胶料的修复效率为59%,当愈合时间延长到5 h时,修复效率高达99%;IIR的加入提高了整个体系的物理缠结程度,并提供一定的物理修复行为,有助于ZDMA在体系中的分散;NR-IIR较好的共混效果可以帮助固定体系中游离态的分子链,增加了胶料的储能模量。其次,本文以顺丁橡胶(BR)和丁基橡胶(IIR)为主要橡胶组分,采用两步法,首先在DCP的存在下,先进行ZDMA聚合,形成p-ZDMA,然后再通过硫化过程,将p-ZDMA接枝聚合到橡胶网络中,形成了由共价交联和离子交联构成的可逆超分子网络。实验表明,在30 min愈合时间内,BR/ZDMA胶料的修复效率为40%,愈合时间延长到5 h时,修复效率增大到77%;当ZDMA用量为40 phr时,BR和BR-IIR胶料力学性能最好,分别为1.71 MPa和2.85 MPa;IIR的加入提高了反应体系的活化能,增加了橡胶样品的交联程度。本文还利用环氧化天然橡胶(ENR)在酸性条件下开环生成带有羟基(-OH)基团的开环产物,与二苯基甲烷二异氰酸酯(MDI)反应以及ZDMA的接枝聚合,将可逆氢键结构和部分离子交联引入ENR的交联网络中。通过控制硫化过程,形成了由可逆氢键、离子交联和共价交联共同组成的多重可逆超分子网络,成功制备了具有优异自愈能力和力学性能的ENR自修复弹性体材料。实验表明,ENR自修复材料,在30 min的愈合时间内,修复效率高达69%,明显大于同等修复条件下NR/ZDMA胶料的自修复效率。氢键结构起到交联和缠结的作用,牢牢固定分子链,限制分子链的移动,拉伸时不容易断裂,在较小的应变下,展现出最佳的抗拉强度。更多还原

【Abstract】 Rubber materials are always susceptible to mechanical damage during processing and use.It finally leads to catastrophic failure of the rubber,resulting in material waste and environment damage.In order to improve the durability of rubber,different type of reversible cross-links has been introduced into the cross-linked network structure of rubber in this thesis.Those reversable connections can automatically repair the damage,effectively prolonging the service life of rubber.In this thesis,natural rubber(NR)and butyl rubber(IIR)are used as the main rubber components,and zinc dimethacrylate(ZDMA)is used as the provider of ionic bonds,or ionic clusters.By controlling the vulcanization process,ZDMA is grafted to the rubber molecular chain.A reversible supramolecular network composing of covalent cross-linking,ionic cross-linking,and physical entanglement is formed.Experiments show that the repair efficiency of the NR/ZDMA compound is 59 % within the healing time of only 30 min at room temperature.When the healing time is extended to 5 h,the repair efficiency is as high as 99 %.The addition of IIR improves the physical properties of the whole system.The entanglements provided by IIR benefits the physical repair behavior.Meanwhile,it is also helpful for the dispersion of ZDMA in the system.The better blending effect of NR-IIR can help fix the free molecular chains in the system and increase the storage modulus of the rubber compound.Secondly,in this project,cis-butadiene rubber(BR)and butyl rubber(IIR)have been used as the main rubber components to prepare rubber compound.The compounding depends on a two-step method.First,in the presence of DCP,ZDMA is polymerized to form p-ZDMA.Then during the vulcanization process,p-ZDMA was grafted into the rubber network,forming a reversible supramolecular network composed of covalent,and ionic crosslinks.Experiments show that the repair efficiency of BR/ZDMA compound is 40 % within 30 min healing time.The repair efficiency increases to 77 % when the healing time is extended to 5 h.When the dosage of ZDMA is 40 phr,the BR and BR-IIR compound had the best mechanical properties,which were 1.71 MPa and 2.85 MPa,respectively.The addition of IIR increased the activation energy of the reaction system and increased the degree of cross-linking of the rubber samples.In this thesis,the self-healing behavior of ring-opened epoxidized natural rubber(ENR)has also been studied.ENR was first treated under acidic conditions to generate a ring-opening product with hydroxyl(-OH)group.Then,it reacted with diphenylmethane diisocyanate(MDI)and the graft with p-ZDMA.The reversible hydrogen-bonding structure and partial ionic cross-linking are introduced into the cross-linked network of ENR.By controlling the vulcanization process,multiple reversible supramolecular networks composed of reversible hydrogen bonds,ionic crosslinks and covalent crosslinks were formed.ENR self-healing elastomer materials with excellent self-healing ability and mechanical properties were successfully prepared.Experiments show that the selfhealing efficiency of ENR self-healing material is as high as 69 % within the healing time of 30 min,which is significantly greater than the selfhealing efficiency of NR/ZDMA compound under the same repair conditions.The hydrogen bond structure plays the role of cross-linking and entanglement,firmly fixing the molecular chain,restricting the movement of the molecular chain.It made the chains are not easy to break when stretched,and showing the best tensile strength under small strain.更多还原