新型螺旋聚乙炔纳米复合材料的制备及其红外性能研究

发布时间：2018-05-17 07:55

本文选题：螺旋聚合物 + 纳米复合材料　；参考：《东南大学》2017年硕士论文

【摘要】：高分子化合物具有抗腐蚀、密度低、功能多样性等优异的物理化学性能,使其在光电领域有巨大应用潜力,尤其是分子尺度上的结构变化和组成的可调性为实现人工调控材料的红外发射率提供新的途径。螺旋聚合物因其规整有序的高级分子结构成为一类具有实用价值的低红外发射率材料,精准有序的螺旋结构能有效降低高分子化合物中不饱和基团的缺氢程度,从而改变分子的振动模式,将材料的红外发射率降低至理想值。另外,将具有光学活性的螺旋聚合物与纳米材料进行杂化,可充分利用无机纳米粒子的量子尺寸效应和表面效应,增强高分子与无机纳米粒子间的界面作用,进而降低有机无机杂化体系的红外辐射能量。本文基于手性豆甾醇和非手性特戊酸,通过酰胺化反应制备了两种炔丙酰胺单体M1和M2,然后经过金属铑催化剂的配位聚合合成出M1单体的自聚物和一系列单体M1、M2的共聚物。将具有稳定螺旋构象的共聚物PA分别与酸化后的多壁碳纳米管f-MWNTs和氧化石墨烯GO等纳米碳材料进行复合,得到PA@f-MWNTs、PA@GO纳米复合材料。采用傅里叶变换红外光谱(FT-IR)、核磁(NMR)、紫外-可见光谱(UV-vis)、圆二色光谱(CD)、凝胶渗透色谱(GPC)、X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)、X射线光电子能谱(XPS)、热重分析(TGA)等方法表征了螺旋聚合物及其纳米复合材料的结构和性能,同时测试了它们在8-14μm的红外发射率。实验结果总结如下:1.螺旋聚合物的合成、表征及其红外辐射特性基于豆甾醇的手性N-炔丙酰胺单体M1在铑金属催化剂的配位聚合作用下聚合成为分子量适中且分布均匀的螺旋聚乙炔分子poly(M1),侧链中N-H键、C=O键等化学键形成分子间或分子内氢键产生的不对称作用力是构建和维持螺旋构象的重要驱动力,其中酰胺基的N-H键和C=O键选择性参与了分子间和分子内氢键,而酯结构中的C=O键主要参与形成分子内氢键。聚合物螺旋结构的的稳定性和规整度受多种因素影响,如催化剂含量、溶剂等。将M1与另一种基于特戊酸的N-炔丙酰胺单体M2聚合,以不同单体配比合成出一系列分子量适中且分布均匀的光学活性共聚物。从共聚物的圆二色谱中可发现,共聚物螺旋结构的有序性随组分变化发生显著改变,当M1与M2摩尔配比为1:2时,分子侧链氢键作用力与空间排斥力达到最佳的协同效应,共聚物Poly(M10.33-co-M20.67)达到最有序、最稳定的结构,并表现出最高的光学活性。通过测定材料的红外发射率值发现,螺旋聚合物的结构越稳定,其红外发射率值也越低,共聚物Poly(M10.33-co-M20.67)的红外发射率可低至 0.536。2.螺旋聚炔与多壁碳纳米管的复合及其红外辐射特性用高温浓酸蒸汽氧化多壁碳纳米管,使其表面带有含氧的活性基团,采用溶液共混的方法将螺旋聚合物包覆在碳纳米管的表面,制备得到PA@f-MWNTs纳米复合粒子。从表征结果可以看出复合过程仅发生在碳纳米管的表面,聚合物分子与以缠绕的方式均匀地包覆在其表面,碳纳米管内部的晶体结构没有遭到破坏。复合纳米粒子仍具有较好的光学活性和热稳定性。相比于纯的碳纳米管,PA@f-MWNTs纳米复合粒子的红外发射率有所下降,表明聚合物分子与碳纳米管表面的π-π轭作用和电子转移有助于降低复合物的红外发射率。3.螺旋聚炔与氧化石墨烯的复合及其红外辐射特性通过溶液共混的方法将螺旋聚合物与氧化石墨烯进行复合,制备了 PA@GO纳米复合物。复合过程中聚合物仍保持一定的螺旋二级结构,并以无规则的岛状聚集状态附着在氧化石墨烯层的表面,PA结构中特殊官能团与氧化石墨烯片层上的含氧基团形成氢键对于提高聚合物螺旋结构的有序度具有极大作用。该PA@GO纳米粒子的红外发射率(ε=0.593)低于PA与GO的直接混合物的红外发射率(ε=0.704),表明通过结合有机无机的界面作用和螺旋聚合物的光学活性能有效地降低纳米材料的红外发射率。
[Abstract]:Polymer compounds have excellent physical and chemical properties such as corrosion resistance, low density, functional diversity and so on. They have great potential in the field of photoelectric applications, especially the structural changes and composition of molecular scales to provide a new way to realize the infrared emissivity of artificial control materials. The molecular structure becomes a kind of low infrared emissivity material of practical value. The accurate and ordered spiral structure can effectively reduce the degree of hydrogen deficiency of the unsaturated group in the polymer, thus change the molecular vibration mode and reduce the infrared emissivity of the material to the ideal value. The material is hybrid, which can make full use of the quantum size effect and surface effect of inorganic nanoparticles, enhance the interfacial action between the polymer and the inorganic nanoparticles, and then reduce the infrared radiation energy of the organic and inorganic hybrid system. In this paper, two kinds of propargides are prepared by the acylation reaction of chiral and chiral amyl The monomer M1 and M2 were synthesized by the coordination polymerization of the metal rhodium catalyst, and the polymer of M1 monomer and a series of monomer M1, M2 copolymers were synthesized. The copolymers with stable spiral conformation PA were combined with the acidified carbon nanotube f-MWNTs and graphene oxide GO and so on, and PA@f-MWNTs, PA@GO nanocomposites were obtained. Materials. Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic (NMR), ultraviolet visible spectrum (UV-vis), circular two color spectroscopy (CD), gel permeation chromatography (GPC), X ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA) and other methods have been used to characterize the structure and structure of the spiral polymer and its nanocomposites. Performance, and test their infrared emissivity at 8-14 m. The results are summarized as follows: 1. the synthesis, characterization and infrared radiation characteristics of 1. helix polymers are based on the coordination polymerization of the RH metal catalyst, which is based on the coordination polymerization of the rhodium metal catalyst, and becomes a moderately molecular and evenly distributed polyacetylene molecule pol Y (M1), the chemical bonds, such as N-H bonds and C=O bonds in the side chain, form the asymmetric forces produced by the intermolecular or intramolecular hydrogen bonds. The N-H and C=O bonds of the amide group selectively participate in the intermolecular and intramolecular hydrogen bonds, while the C=O bonds in the ester structure are mainly involved in the formation of intramolecular hydrogen bonds. Polymer snail. The stability and regularity of the spin structure are influenced by a variety of factors, such as the content of the catalyst, the solvent and so on. A series of optical active copolymers with moderate molecular weight and uniform distribution are synthesized by the polymerization of M1 and a N- propargamide monomer based on the different monomers based on the different monomers. From the round two chromatography of the copolymer, the copolymer snails can be found. When the molar ratio of M1 to M2 is 1:2, the best synergistic effect is reached between the hydrogen bond force of the molecular side chain and the spatial repulsion force. The copolymer Poly (M10.33-co-M20.67) reaches the most ordered, most stable structure and shows the highest optical activity. By measuring the infrared emissivity of the material. It is found that the structure of the spiral polymer is more stable and its infrared emissivity is lower. The infrared emissivity of the copolymer Poly (M10.33-co-M20.67) can be lower to the compound of 0.536.2. spiral polyacetylene and multi wall carbon nanotube and its infrared radiation characteristics by oxidation of multi wall carbon nanometers with high temperature concentrated acid steam, which makes the surface with the active group containing oxygen. PA@f-MWNTs nanocomposite particles are prepared by coating the spiral polymer on the surface of the carbon nanotube. From the result of the characterization, it can be seen that the composite process only occurs on the surface of the carbon nanotube. The polymer molecules are uniformly coated on the surface of the nanotube, and the crystal structure inside the carbon nanotubes has not been destroyed. The composite nanoparticles still have good optical activity and thermal stability. Compared with pure carbon nanotubes, the infrared emissivity of PA@f-MWNTs nanocomposite particles has been reduced. It is indicated that the pion binding and electron transfer of polymer molecules on the surface of carbon nanotubes and electron transfer can help to reduce the infrared emissivity of the complex.3. spiral polyacetylene and graphite oxide. The composite of alkene and its infrared radiation are mixed with the solution of solution by mixing the spiral polymer and graphene oxide, and the PA@GO nanocomposites are prepared. The polymer still maintains a certain spiral two structure and adheres to the surface of the oxygen fossils in the amorphous state of the island, and the special officer in the PA structure. The formation of hydrogen bonds between the energetic group and the oxygen containing groups on the graphene oxide layer has a great effect on improving the order of the polymer spiral structure. The infrared emissivity of the PA@GO nanoparticles (epsilon =0.593) is lower than the infrared emissivity of the direct mixture of PA and GO (epsilon =0.704), indicating the interaction of organic-inorganic interfaces and spiral polymers. Optical activity can effectively reduce the infrared emissivity of nanomaterials.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O632.17;TB33

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