氧化石墨烯的功能化及其水性聚氨酯复合体系的研究
发布时间：2019-07-08 12:33
【摘要】：本论文以改善石墨烯在聚氨酯中的分散性和界面相容性为目的,通过氧化石墨烯的功能化、聚氨酯的分子设计及创新共混复合方法等手段,制备了几种石墨塑与聚氨酯以不同作用方式形成的水性聚氨酯-石墨烯复合体系,并分别对其结构、形态和性能进行了分析和研究,主要内容如下:1)利用两亲共聚物poly(SS-co-AMPS)对石墨烯进行非共价键修饰,制备了一种在水或有机溶剂中均可稳定分散的功能化石墨烯FGNs。通过溶液混合的方式实现了FGNs在磺酸型水性聚氨酯(SWPU)中的均匀分散,制备了SWPU/FGNs复合体系。对复合体系的微观结构分析发现,FGNs呈高度剥离的状态均匀分散在聚氨酯中;对SWPU/FGNs的粘结强度与结晶性能的研究分析,由于FGNs可提高CWPU的结晶速率和结晶度,从而可显著改善其粘结强度;另外,FGNs将SWPU的导电率提升了5.5×1010倍,可达到0.39S.m-1结果表明,该方法所制备的聚氨酯/石墨烯复合体系在环保型聚氨酯导电粘合剂方面具有潜在的应用价值。2)将氧化石墨烯(GO)与过量的甲苯二异氰酸酯(TDI)反应后用水合肼处理,得到一种表面含伯氨基(-NH2)的功能化石墨烯NH2-graphene,然后以NH2-graphene为扩链剂通过原位聚合法制备了石墨烯共价键改性的水性聚氨酯分散液。由于石墨烯与聚氨酯之间存在共价键连接,NH2-graphene在复合体系中不仅可均匀分散,而且与聚氨酯之间具有较强的界面作用力,另外NH2-graphene可导致聚氨酯微相分离度的增加。性能研究发现,NH2-graphene可显著改善水性聚氨酯的力学、耐热和导热性能。3)将阳离子水性聚氨酯(CWPU)与GO水分散液混合,利用带正电荷的CWPU胶粒可通过静电作用吸附到带负电的GO表面发生共沉淀的原理制备了聚氨酯/石墨烯复合材料。研究发现,化学还原氧化石墨烯(RGO)与CWPU之间通过静电相互作用,均匀的分散在聚氨酯基体中;结果表明,CWPU/RGO的导电率和导热率比纯的CWPU分别提高了6.1倍和4.9×109倍;另外,涂覆了CWPU/RGO的PET膜的氧气透过率(OTR)可达0.6cm3.m-2 day-1,表现出优异的气体阻隔性能。4)将CWPU与GO的水分散液混合制备了CWPU/GO复合体系,研究了聚氨酯胶粒粒径、GO的pH值以及Zeta电位对体系稳定性的影响。研究发现,CWPU胶粒和片状GO通过静电吸附组成的CWPU/GO复合体受到重力、浮力、分散力和静电排斥等作叫力,其受力情况是决定复合体系稳定分散或沉淀的主要因素,当CWPU胶粒粒径小于100nm、GO的pH值为9.0左右时可得到稳定分散的复合体系。TEM和SEM的分析发现,GO可均匀地分散在复合体系中;结果表明,CWPU/GO的耐热、力学和氧气阻隔性能比纯的CWPU均有显著提高。
文内图片：
图片说明：图１－１石墨烯的结构模型（ａ）和微观形貌图（ｂ，ｃ，，ｄ）逡逑Ｆｉｇ邋１．１邋Ｈｏｎｅｙ－ｃｏｍｂ邋ｌａｔｔｉｃｅ邋ｓｔｒｕｃｔｕｒｅ邋（ａ）邋ａｎｄ邋ｍｉｃｒｏｍｏｒ－ｐｈｏｌｏｇｉｅｓ邋ｏｆ邋ｇｒａｐｈｅｎｅ邋ｎａｎｏｐｌａｔｅｌｅｔｓ邋（ｂ，邋ｃ，邋ｄ）逡逑且非常稳定，使得石墨烯成为目前世界上所发现的材料中机械强度最优异的材料，Ｌｅｅ等人［２２］逡逑２
[Abstract]:In order to improve the dispersion and interfacial compatibility of graphene in polyurethane, several waterborne polyurethane-graphene composite systems formed by graphite plastic and polyurethane were prepared by means of functionalization of graphene oxide, molecular design of polyurethane and innovative blending method, and their structure, morphology and properties were analyzed and studied respectively. The main contents are as follows: 1) graphene was modified by non-covalent bond modification with Amphiphilic Copolymer poly (SS-co-AMPS). A functional fossil graphene FGNs., which can be stably dispersed in water or organic solvent, was prepared. The uniform dispersion of FGNs in sulfonic acid waterborne polyurethane (SWPU) was realized by solution mixing, and the SWPU/FGNs composite system was prepared. The microstructure analysis of the composite system shows that FGNs is uniformly dispersed in polyurethane in the state of high peeling, and the bond strength and crystallization properties of SWPU/FGNs can be significantly improved because FGNs can increase the crystallization rate and degree of crystallization of CWPU. In addition, the conductivity of SWPU was increased by 5.5 脳 1010 times by FGNs, and the results of 0.39S.m-1 showed that the polyurethane / graphene composite system prepared by this method had potential application value in environmentally friendly polyurethane conductive adhesive. 2) graphene oxide (GO) was reacted with excess toluene diisocyanate (TDI) and treated with hydrazide hydrate. A functional fossil graphene NH2-graphene, containing basic amino group (- NH2) on the surface was obtained and then graphene covalent bond modified waterborne polyurethane dispersion was prepared by in situ polymerization with NH2-graphene as chain extender. Because of the covalent bond connection between graphene and polyurethane, NH2-graphene can not only disperse uniformly in the composite system, but also have a strong interfacial force with polyurethane. In addition, NH2-graphene can lead to the increase of microphase separation of polyurethane. It was found that NH2-graphene could significantly improve the mechanical, heat and thermal conductivity of waterborne polyurethane. 3) Polyurethanes / graphene composites were prepared by mixing cationic waterborne polyurethane (CWPU) with GO water dispersion, and using the principle that positively charged CWPU particles could be adsorbed on the surface of GO with negative electricity by electrostatic interaction. It is found that the chemical reduction graphene oxide (RGO) and CWPU are uniformly dispersed in polyurethane matrix by electrostatic interaction, the results show that the conductivity and thermal conductivity of CWPU/RGO are 6.1 times and 4.9 脳 109 times higher than those of pure CWPU, respectively. In addition, the oxygen transmittance (OTR) of PET film coated with CWPU/RGO showed excellent gas barrier performance. 4) the CWPU/GO composite system was prepared by mixing the water dispersion of CWPU and GO. The effects of particle size of polyurethane particles, pH value of GO and Zeta potential on the stability of the system were studied. It is found that the CWPU/GO complex composed of CWPU colloidal particles and flake GO by electrostatic adsorption is called by gravity, buoyancy, dispersion force and electrostatic exclusion, and its stress is the main factor determining the stable dispersion or precipitation of the composite system. When the particle size of CWPU colloidal particles is less than 100 nm and the pH value of go is about 9.0, the stable dispersion composite system can be obtained. Tem and SEM analysis show that GO can be uniformly dispersed in the composite system. The results show that the heat resistance, mechanics and oxygen barrier properties of CWPU/GO are significantly higher than those of pure CWPU.
【学位授予单位】：合肥工业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TQ127.11;TB332
本文编号：2511587
文内图片：
图片说明：图１－１石墨烯的结构模型（ａ）和微观形貌图（ｂ，ｃ，，ｄ）逡逑Ｆｉｇ邋１．１邋Ｈｏｎｅｙ－ｃｏｍｂ邋ｌａｔｔｉｃｅ邋ｓｔｒｕｃｔｕｒｅ邋（ａ）邋ａｎｄ邋ｍｉｃｒｏｍｏｒ－ｐｈｏｌｏｇｉｅｓ邋ｏｆ邋ｇｒａｐｈｅｎｅ邋ｎａｎｏｐｌａｔｅｌｅｔｓ邋（ｂ，邋ｃ，邋ｄ）逡逑且非常稳定，使得石墨烯成为目前世界上所发现的材料中机械强度最优异的材料，Ｌｅｅ等人［２２］逡逑２
[Abstract]:In order to improve the dispersion and interfacial compatibility of graphene in polyurethane, several waterborne polyurethane-graphene composite systems formed by graphite plastic and polyurethane were prepared by means of functionalization of graphene oxide, molecular design of polyurethane and innovative blending method, and their structure, morphology and properties were analyzed and studied respectively. The main contents are as follows: 1) graphene was modified by non-covalent bond modification with Amphiphilic Copolymer poly (SS-co-AMPS). A functional fossil graphene FGNs., which can be stably dispersed in water or organic solvent, was prepared. The uniform dispersion of FGNs in sulfonic acid waterborne polyurethane (SWPU) was realized by solution mixing, and the SWPU/FGNs composite system was prepared. The microstructure analysis of the composite system shows that FGNs is uniformly dispersed in polyurethane in the state of high peeling, and the bond strength and crystallization properties of SWPU/FGNs can be significantly improved because FGNs can increase the crystallization rate and degree of crystallization of CWPU. In addition, the conductivity of SWPU was increased by 5.5 脳 1010 times by FGNs, and the results of 0.39S.m-1 showed that the polyurethane / graphene composite system prepared by this method had potential application value in environmentally friendly polyurethane conductive adhesive. 2) graphene oxide (GO) was reacted with excess toluene diisocyanate (TDI) and treated with hydrazide hydrate. A functional fossil graphene NH2-graphene, containing basic amino group (- NH2) on the surface was obtained and then graphene covalent bond modified waterborne polyurethane dispersion was prepared by in situ polymerization with NH2-graphene as chain extender. Because of the covalent bond connection between graphene and polyurethane, NH2-graphene can not only disperse uniformly in the composite system, but also have a strong interfacial force with polyurethane. In addition, NH2-graphene can lead to the increase of microphase separation of polyurethane. It was found that NH2-graphene could significantly improve the mechanical, heat and thermal conductivity of waterborne polyurethane. 3) Polyurethanes / graphene composites were prepared by mixing cationic waterborne polyurethane (CWPU) with GO water dispersion, and using the principle that positively charged CWPU particles could be adsorbed on the surface of GO with negative electricity by electrostatic interaction. It is found that the chemical reduction graphene oxide (RGO) and CWPU are uniformly dispersed in polyurethane matrix by electrostatic interaction, the results show that the conductivity and thermal conductivity of CWPU/RGO are 6.1 times and 4.9 脳 109 times higher than those of pure CWPU, respectively. In addition, the oxygen transmittance (OTR) of PET film coated with CWPU/RGO showed excellent gas barrier performance. 4) the CWPU/GO composite system was prepared by mixing the water dispersion of CWPU and GO. The effects of particle size of polyurethane particles, pH value of GO and Zeta potential on the stability of the system were studied. It is found that the CWPU/GO complex composed of CWPU colloidal particles and flake GO by electrostatic adsorption is called by gravity, buoyancy, dispersion force and electrostatic exclusion, and its stress is the main factor determining the stable dispersion or precipitation of the composite system. When the particle size of CWPU colloidal particles is less than 100 nm and the pH value of go is about 9.0, the stable dispersion composite system can be obtained. Tem and SEM analysis show that GO can be uniformly dispersed in the composite system. The results show that the heat resistance, mechanics and oxygen barrier properties of CWPU/GO are significantly higher than those of pure CWPU.
【学位授予单位】：合肥工业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TQ127.11;TB332
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