【作者】 王晓；

【导师】 冯圣玉； 李磊；

【作者基本信息】 山东大学 ， 高分子化学与物理， 2022， 硕士

【摘要】 有机硅高分子具有耐高低温、耐老化、电气绝缘、生物相容性好、表面张力低等独特而优异的性能,因而以硅油、硅橡胶、硅树脂等形式在航空航天、电子电气、化工、医疗等领域得到广泛的应用。然而传统有机硅材料以共价键交联,使其无法进行二次加工和再循环利用,这无疑会缩短材料的使用寿命,造成资源浪费和环境污染问题,不符合绿色可持续发展的要求。近年来,将超分子相互作用和动态共价键引入到聚硅氧烷主链、侧链或交联点中,使其具有动态性得到了研究者的广泛关注。所得的材料体现出前所未有的自修复性、刺激响应性和环境适应性等功能特性。传统有机硅高分子合成方法有限、反应条件严苛,因此限制了其动态功能材料的发展。席夫碱反应和胺-环氧反应具有点击、高效的特点,有望为构筑新型聚硅氧烷材料提供简单有效的途径。前者是指一级胺与醛基发生缩合,生成亚胺键(C=N)的反应。该反应温和高效、无需催化剂、副产物只有水。亚胺键是一种动态共价键,氮原子上的孤对电子又使其具有良好的金属配位能力。后者是指氨基与环氧基团之间的亲核反应,具有单体多样、条件温和、官能团容忍度高等优势。本文通过席夫碱反应对侧氨丙基硅油进行官能化修饰,制得了金属配位型和氢键型超分子聚硅氧烷弹性体,利用胺-环氧点击反应构筑新型聚(硅氧烷-胺),用对苯二硼酸作为交联剂,制得了硼酸酯交联的聚硅氧烷塑料。对这些超分子弹性体和动态共价交联塑料的力学性质和动态性能进行了表征,具体概括如下:1、通过侧氨丙基硅油与2-羟基萘甲醛之间的席夫碱反应,将邻羟基萘亚胺双齿配体结构引入聚硅氧烷中,然后分别与锌、铜、铁三种金属盐离子配位,合成了一系列新型金属配位聚硅氧烷。紫外吸收和荧光光谱表明,该官能化聚硅氧烷可有效检测Fe3+、Zn2+和Al3+。其中,弹性体Pl-10%-Fe3+的拉伸强度高达8.8 MPa,韧性为33.22 MJ/m3。配位键和亚胺键的动态特性使这些弹性体具有自修复性和热压可再加工能力。由于玻璃化转变温度和拓扑结构重排温度的合理间隔,该弹性体具有可塑的双重形状记忆能力,可以通过加热-冷却过程改变弹性体的永久形状和临时形状。实验证明,金属配位交联可提供同时具有较好力学性质和动态可逆性的聚硅氧烷弹性体。2、利用侧氨丙基硅油与3,4-二羟基苯甲醛之间的席夫碱反应将邻苯二酚基团引入到聚硅氧烷侧链上,对其进行了官能化后修饰,并探究了它的多种功能化应用。(1)利用邻苯二酚基团与金属表面的配位作用,开发了一种对钢片表面具有较强粘结力的胶黏剂;(2)利用邻苯二酚之间的氢键相互作用,制备了一种氢键交联弹性体,并对其热学性质、力学性质以及自愈合能力进行了表征;(3)向该氢键交联弹性体中掺杂多臂碳纳米管,成功制备了一种可自修复的、具有导电性的弹性体材料,其展现出在柔性导电材料方面潜在的应用价值;(4)利用硅氧烷链段的疏水性、邻苯二酚基团对基材表面的粘附性,并掺杂纳米二氧化硅进一步提高表面粗糙度,制备了具有抗污防水效果的疏水涂层。3、利用不同伯胺与1,3-双(3-缩水甘油醚氧基丙基)四甲基二硅氧烷之间的胺-环氧点击反应构筑聚合物主链,然后将环氧开环产生的二乙醇胺结构作为反应基团,用对苯二硼酸作为交联剂,制得了硼酸酯键交联的含硅聚合物塑料。该塑料具有较好的透明性,紫外透光率达到85%;在室温下具有很高的模量和拉伸强度,可以作为硬质塑料使用;硼酸酯键赋予该塑料动态性:(1)在水和乙醇的辅助下,该塑料具有室温自修复性;(2)基于硼酸酯交换反应的热可逆性,该塑料具有良好的热压可再加工性;(3)由于硼酸酯键与乙醇的反应,该塑料可以通过乙醇-四氢呋喃混合溶剂实现化学回收再成型后可恢复初始的机械性能;(4)在溶剂辅助下,热压成型的片状样品可以在较低的温度下重构成其他二维或三维形状。同时通过动态热机械分析和蠕变-恢复测试对该塑料材料的粘弹性特征进行了探究,发现其具备灵敏的温度响应性。更多还原

【Abstract】 Silicone polymers have unique and excellent properties such as high and low temperature resistance,aging resistance,electrical insulation,good biocompatibility,and low surface tension.Silicone oils,silicone rubbers,silicone resins and other forms are widely used in aerospace,electronics,chemical,medical and other fields.However,the current cross-linking of silicone materials is mainly irreversible covalent bonds,which cannot be reprocessed and recycled.This will undoubtedly shorten the service life of materials,causing resource waste and environmental pollution and againsting the requirements of green and sustainable development.In recent years,the introduction of supramolecular interactions and dynamic covalent bonds into polysiloxane backbones,side chains,or crosslinks to design dynamic materials has received great attention.The resulting materials have multiple functionalities such as excellent selfhealing,stimuli-responsiveness,reversibility,and environmental adaptability.Traditional organosilicon polymer synthesis methods are limited and the reaction conditions are harsh,thus limiting the development of its dynamic functional materials.The Schiff base reaction and amine-epoxy reaction have the characteristics of click and high efficiency,and are expected to provide a simple and effective way to construct new polysiloxane materials.The former refers to the condensation of a primary amine with an aldehyde group to form an imine bond(C=N).The reaction is mild and efficient,no catalyst is required,and only water is the by-product.The imine bond is a dynamic covalent bond,and the lone pair of electrons on the nitrogen atom makes it have good metal coordination ability.The latter refers to the nucleophilic reaction between amino groups and epoxy groups,which has the advantages of diverse monomers,mild conditions,and high functional group tolerance.In this paper,the polydimethylsiloxane with amino side groups was post-modified by Schiff base reaction.Both metal coordinationed and hydrogen bonded supramolecular elastomers were prepared.In addition,a new type of silicon-containing polymer was constructed by amine-epoxy click reaction,and terephenyl diboronic acid was added to prepare borate cross-linked silicon-containing polymer plastic.The mechanical properties and dynamics of these supramolecular elastomers and dynamic covalently cross-linked materials were characterized,which are summarized as follows:1.A new type of coordination polysiloxane was synthesized by introducing the bidentate ligand structure of o-hydroxynaphthalene imine into the polymer through the Schiff base reaction between polydimethylsiloxane with amino side groups and 2hydroxynaphthaldehyde.UV-Vis and fluorescence spectra show that the coordination polysiloxane can effectively detect Fe3+,Zn2+and Al3+.The elastomer P1-10%-Fe3+has the highest tensile strength of 8.8 MPa and the toughness of 33.22 MJ/m3.The dynamic nature of coordinative and imine bonds makes these elastomers self-healing and reprocessable.Due to the reasonable spacing of the glass transition temperature and topological rearrangement temperature,the elastomer possesses a plastic dual shape memory capability,which can change the permanent and temporary shape of the elastomer through a heating-cooling process.Experiments show that metal coordination crosslinking can simultaneously provide polysiloxane elastomers with better mechanical properties and dynamic reversibility.2.Via the Schiff base reaction between amino silicone oil and 3,4dihydroxybenzaldehyde,the catechol group was introduced into the polysiloxane side chain.Its various functional applications are explored.(1)an adhesive with strong adhesion to the surface of the steel sheet was developed by utilizing the coordination between the catechol group and the metal surface;(2)using the hydrogen bond between the catechols,a hydrogen-bonded cross-linked elastomer was prepared,and its thermal properties,mechanical properties and self-healing ability were characterized;(3)doping multi-armed carbon nanotubes into the hydrogen-bonded cross-linked elastomer successfully prepared a stretchable and self-healing conductive elastomer,which showed potential application value in flexible conductive materials;(4)using the hydrophobicity of the siloxane segment and the adhesion of the catechol group to the surface of the substrate,and doping with nano-silica to further improve the surface roughness,a hydrophobic coating with antifouling and waterproofing effect was prepared.3.The main chains of the polymers were constructed by the amine-epoxy click reaction between different primary amines and 1,3-bis(3-glycidyloxypropyl)tetramethyldisiloxane.Then the diethanolamine structure produced by epoxy ring opening is used as the reactive group.with terephenyl diboronic acid as the crosslinking agent,a polymer plastic cross-linked by boronate bonds was prepared.The plastic has good transparency,and the UV transmittance reaches 85%.It has high modulus and tensile strength at room temperature.The boronate bond gives the plastic dynamic:(1)with the assistance of water and ethanol,the plastic has self-healing properties at room temperature;(2)based on the thermal reversibility of the boron ester exchange reaction,the plastic has good hot-pressing reprocessability;(3)due to the reaction of boron ester bond with ethanol,the plastic can be chemically recycled and reused through the ethanol-THF mixed solvent,and the original mechanical properties can be restored;(4)the sheet material obtained by hot pressing can be reshaped into other two-dimensional or three-dimensional shape with assistance of solvent.The viscoelastic characteristics of the plastic material were explored through dynamic thermomechanical analysis and creep and recovery tests,and it was found that the plastic had a high sensitivity to temperature.更多还原