聚合物功能化石墨烯的合成及应用研究进展(二)

着重评述了采用共价连接和非共价连接技术制备聚合物功能化石墨烯的方法,介绍了聚合物功能化石墨烯的应用概况。     

功能化石墨烯/聚合物阻燃材料研究进展

石墨烯具有很多优异的性能,拥有巨大的比表面积、可见光透明度高、有良好的力学性能、热学性能、电学性能。功能化石墨烯是对石墨烯进行改性,改性方法主要有共价键功能化和非共价键功能化。聚合物材料在生活中应用广泛,但极易燃烧,对聚合物阻燃研究十分必要。本文综述了石墨烯的功能化方法及功能化石墨烯/聚合物阻燃材料的研究进展。     

石墨烯的共价键功能化研究进展

为了克服石墨烯不溶于水及常见有机溶剂的缺陷,并扩展石墨烯的应用范围,就有必要对石墨烯进行功能化。共价键功能化和非共价键功能化是石墨烯功能化常见的两种方式,其中石墨烯的共价键功能化主要包括有机小分子共价键功能化和聚合物共价键功能化等。本文综述了近年来石墨烯共价键功能化方面的研究进展,比较了石墨烯共价键功能化和非共价键功能化的不同之处,对石墨烯共价键功能化的发展前景进行了展望。     

石墨烯在聚合物复合材料中的应用研究进展

综述了石墨烯的合成和表征方法,以及提高聚合物与石墨烯相互作用的方法,强调了功能化修饰石墨烯的重要性及其与聚合物混合后形成的热固性复合材料的性能。石墨烯的研究方向主要包括基于石墨烯的纳米复合材料的制备及改性、具有特殊性能的石墨烯改性热固性聚合物复合材料等。分析了环氧基树脂/石墨烯复合材料的合成与性能,功能化修饰石墨烯的方法,以及石墨烯改性热固性聚合物复合材料中界面的作用及其对复合材料整体性能的影响。     

应用于聚合物基复合材料的功能化石墨烯研究进展

石墨烯强度高、导电性和导热性好、透明性高,是理想的复合材料增强剂,但是,石墨烯的"两憎"特性导致其在溶液中的分散性差。本文介绍了氧化石墨烯(GO)的制备方法,以及对GO功能化处理的两种方法,共价改性和非共价改性;并进一步介绍石墨烯复合材料的制备方法。     

石墨烯基聚合物复合材料热性能的分子动力学研究

在石墨烯上采用碳氢基链接枝的化学功能化法以提高石墨烯基聚合物复合材料的热性能。其中分子动力学模拟(MD)用于确定单层石墨烯和石墨烯基聚合物纳米复合材料的导热系数。采用非平衡分子动力学(NEMD)模拟研究了石墨烯的碳链功能化对石墨烯基聚乙烯纳米复合材料界面热导的影响,探讨了接枝密度(碳氢链数)对石墨烯和纳米复合材料导热性能的影响。     

氧化石墨烯在阻燃聚合物中的应用研究进展

石墨烯作为一种重要的碳材料,具有非常好的热稳定性能、力学性能,可以将其作为阻燃剂运用到聚合物材料中,从而提高复合材料的阻燃性能。而氧化石墨烯作为石墨烯的一种衍生物,在经过功能化后不仅弥补了其在高分子材料中难于分散的缺点,并且还可以通过表面改性引入其他元素赋予石墨烯新的性能。本文综述了氧化石墨烯及其修饰后的功能化石墨烯在阻燃聚合物中的应用研究进展。     

共价改性石墨烯的研究进展

石墨烯由于优异的热学、电学、力学、光学性能已经成为了当今研究的热点。但是石墨烯具有强烈的化学惰性,难以利用,而表面改性是解决这一问题的有效途径之一。因此本文综述了近年来石墨烯和氧化石墨烯的共价表面改性研究进展。主要分为两个方面,一方面是针对石墨烯本身碳骨架上C=C键的功能化,另一方面是针对石墨烯的衍生物—氧化石墨烯上含氧官能团的功能化,最后指出了目前还存在的问题以及有望发展的方向。     

油酸功能化石墨烯的制备及其在聚乙烯中的应用

以氧化石墨烯为原料,将油酸分子连接在石墨烯的表面,得到油酸功能化石墨烯,并通过溶液法将其与聚乙烯基体共混获得聚乙烯/功能化石墨烯复合材料,研究了复合材料的导电性能。结果表明,在低石墨烯含量下可大幅提高聚乙烯的导电性能。当油酸功能化石墨烯质量分数为8%时,复合材料的电导率达1 S/m;当油酸功能化石墨烯质量分数为10%时,复合材料的电导率达3 S/m。聚乙烯/功能化石墨烯复合材料在电缆屏蔽、电磁屏蔽和抗静电领域具有应用价值。     

石墨烯/碳纳米管协同改性聚合物纳米复合材料的研究进展

主要介绍了石墨烯和碳纳米管协同改性聚合物纳米复合材料的研究进展,包括石墨烯与碳纳米管的协同作用,制备方法以及功能化方法。并对聚合物/石墨烯/碳纳米管纳米复合材料的制备方法,性能研究和应用现状进行了综述,最后提出了一些展望。     

功能化高分子微球的制备和应用

综述了功能化高分子微球的合成方法和应用领域。用于功能化高分子微球的一般制备方法可以分为直接制备合成带有功能基团的微球及在现有微球上引人功能基团两种,前者包括乳液聚合、悬浮聚合和分散聚合等,而后者有种子聚合法和微球功能化等方法。并对上述方法的特点进行了总结和比较。此外还对各种微球在化工、生物制药等方面的应用作了介绍.     

A Synthetic Approach to Star‐Like Polymers of Styrene and Butyl Acrylate by Linking Reactions using Functionalized Methacrylates

Summary: Coupling reactions between terminal functionalized polymer chains were chosen for the synthesis of star‐like polymers consisting of polystyrene and polystyrene‐block‐poly[styrene‐co‐(butyl acrylate)] arms. For the preparation of terminal functionalized polymer chains a side reaction of the 2,2,6,6‐tetramethylpiperidine‐N‐oxyl (TEMPO) mediated free radical polymerization of methacrylates could be used successfully to convert TEMPO terminated polymers into end functionalized polymers. The number of functionalized monomer units attached to the polymer chain is directly related to the TEMPO concentration during this reaction. Different polystyrenes and polystyrene‐block‐poly[styrene‐co‐(butyl acrylate)] block copolymers were functionalized with a variable number of epoxide and alcohol groups at the chain end. For the determination of the optimal reaction parameters for the coupling reactions between these polymer chains, epoxy functionalized polystyrenes were converted with hydroxy functionalized polystyrenes under basic and acidic conditions. By activation with sodium hydride or boron trifluoride star‐like polymers were synthesized under mild conditions. The transfer of the reaction conditions to coupling reactions between end functionalized polystyrene‐block‐poly[styrene‐co‐(butyl acrylate)] copolymers showed that star‐like polymers with more than 12 arms were formed using boron trifluoride as activating agent.

     

Preparation of doubly responsive polymer functionalized silica hybrid nanoparticles via a one‐pot thiol‐isocyanate click reaction at room temperature

Well‐defined poly(N‐isopropylacrylamide) and poly(2‐(diethylamino) ethyl methacrylate) were synthesized first by a reversible addition‐fragmentation chain transfer process. These polymers were then reduced to generate an end thiol group to react with isocyanate groups on the surface of silica nanoparticles, which were pretreated with toluene‐2,4‐diisocyanate, by a one‐pot “click” reaction to prepare temperature and pH responsive polymer functionalized hybrid silica nanoparticles. The polymer functionalized silica hybrid nanoparticles were characterized by a range of techniques such as Fourier transform infrared spectroscopy and dynamic light scattering. The doubly responsive polymer functionalized silica hybrid nanoparticles show both temperature and pH responsive behavior and their solution properties were dependent on the ratio of the two polymers on the surface of silica. Covalent functionalization of the silica nanoparticle with well‐defined temperature and pH responsive polymers was accomplished via a one‐pot thiol‐isocyanate click reaction. This reaction was found to be extremely efficient in producing doubly responsive polymer functionalized silica hybrid nanoparticle, even at relatively low reaction temperature and short reaction time. Thermogravimetric analysis indicated that the same ratio of poly(N‐isopropylacrylamide) and poly(2‐(diethylamino)ethyl methacrylate) functionalized silica hybrid nanoparticle consisted of 42.46 wt% polymer. POLYM. COMPOS., 38:1454–1461, 2017. © 2015 Society of Plastics Engineers     

Fabrication of pH‐ or temperature‐responsive single wall carbon nanotubes via a graft from photopolymerization

An ultraviolet light initiated “graft from” polymerization method to fabricate polymer‐functionalized single wall carbon nanotubes (SWNTs) with pendant pH‐ and temperature‐responsive polymer chains is utilized. The attached polymer chains, formed from methacrylic acid and poly(ethylene glycol) methyl ether methacrylate monomers, are well established for its pH‐responsive swelling/deswelling behavior. This special property was utilized here to control the aqueous dispersibility of the carbon nanotubes. Furthermore, poly(N‐isopropylacrylamide), a temperature‐responsive polymer, was utilized in the fabrication of SWNTs whose dispersibility was dependent on solution temperature. The morphology of the polymer‐functionalized carbon nanotubes was characterized by scanning electron microscopy (SEM) before and after functionalization. Environmental SEM was used to further characterize the morphology of the functionalized SWNTs. In addition, covalent bonding of the polymer to the carbon nanotube surface was established using Raman and Fourier transform infrared spectroscopic techniques. The physical and chemical properties of the functionalized nanotubes were further characterized by energy‐dispersive X‐ray spectroscopy, thermogravimetric analysis, and differential scanning calorimetry. © 2011 American Institute of Chemical Engineers AIChE J, 58: 2980–2986, 2012     

Mechanical and morphological characterization of polymer-carbon nanocomposites from functionalized carbon nanotubes

Carbon nanotubes were functionalized with poly(vinyl alcohol) (PVA). The water-soluble PVA-functionalized carbon nanotubes were then embedded into PVA matrix via a wet-casting method, resulting in polymer-carbon nanocomposite films with homogeneous nanotube dispersion. Composites with pristine and functionalized nanotubes were tested in tension. It was found that the mechanical properties of these nanocomposite films were significantly improved compared to the neat polymer film. Functionalization allowed good distribution of the nanotubes in the matrix, leading to higher film strength. Scanning electron microscopy shows an apparent good wetting of the nanotubes by the PVA matrix. These results are supportive of good interfacial bonding between the functionalized carbon nanotubes and the hosting polymer matrix.     

Graphene oxide-anchored reactive sulfonated copolymer via simple one pot condensation polymerization: proton-conducting solid electrolytes

A rapid and efficient post-polymerization functionalization of poly(urea-co-urethane) (PUU) onto the graphene oxide (GO) nanosheets has been developed to produce super-acidic polymer/GO hybrid nanosheets. Thus, the surface of GO nanosheets were functionalized with 3-(triethoxysilyl)propyl isocyanate (TESPIC) from hydroxyl groups to yield isocyanate functionalized graphene oxide nanosheets. Then, sulfonated polymer/GO hybrid nanosheets were prepared by condensation polymerization of isocyanate-terminated pre-polyurea onto isocyanate functionalized graphene oxide nanosheets through the formation of carbamate bonds. FTIR and TGA results indicated that TESPIC modifier agent and poly(urea-co-urethane) were successfully grafted onto the GO nanosheets. The grafting efficiency of poly(urea-co-urethane) polymer onto the GO nanosheets was estimated from TGA thermograms to be 205.9%. Also, sulfonated polymer/GO hybrid nanosheets showed a proton conductivity as high as 3.7 mS cm^?1. Modification and morphology of GO nanosheets before and after modification processes were studied by scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray diffraction (XRD).     

Synthesis of a functionalized polythiophene as an active substrate for a label-free electrochemical genosensor

The synthesis of a new functionalized terthiophene monomer with an unsaturated side chain, 3-((2′:2″,5″:2?-terthiophene)-3″-yl) acrylic acid, is described. A conducting polymer was obtained by electropolymerization of the functionalized monomer. The properties of the polymer were investigated using FT-IR, Raman and UV-vis spectroscopy. The application of the polymer as an active substrate for a genosensor is demonstrated by the covalent attachment of amino-end modified oligonucleotide probes to the carboxylic acid group of the polymer. The hybridization of the complementary ODNs can be clearly detected by an increase in the admittance without the need for an indicator or any sample modifications.     

Polysilaethers bearing Si-H and its functionalization via hydrosilylation with acrylic acid

The polysilaether polymers bearing Si-H bonds (PSEHs) were synthesized using Wurtz coupling reaction of dichlorosilanes, mediated by alkali metals, after alcoholysis, the reactant was further hydrolyzed and polycondensation. The Si-H bonds in the macromolecular side chains provide tremendous potentials to prepare a variety of functionalized polysilaethers via hydrosilylation. In this work, the functionalization of PSEHs was carried out via hydrosilylation with acrylic acid and the functionalized derivative was characterized by means of nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, gel permeation chromatography and thermal analysis. It is noted that both PSEHs and the functionalized derivative polymer displayed the characteristics of ultraviolet (UV) absorption and photoluminescence. The functionalized polymers show a considerable blue shift (∼325 nm) and red shift (∼390 nm) in comparison with the starting polymer, which provides the potential to obtain some tunable optoelectronic properties via the structural modifications of PSEHs.     

Organic acids catalyzed polymerization of ε‐caprolactone: Synthesis and characterization

Environmentally friendly organocatalytic synthesis of aliphatic polyesters was studied. The catalysis investigated is novel, and lends itself well to the potential production of valuable biodegradable products. The reactions were based on an organic acids‐catalyzed ring‐opening polymerization of ε‐caprolactone with fatty acid derivatives as the initiator and were performed in the absence of solvents. The chemical structures of the functionalized polymers were confirmed by ¹H and ¹³C‐NMR spectra. Polymers with different molecular weights, in the range 10,900–15,200 were obtained in the presence of fumaric acid as catalyst. The thermal properties of the functionalized PCLs were determined by modulated differential scanning calorimetry and thermogravimetric analysis. The MDSC results verified that the crystallinity and the melting point of the lipid‐functionalized polymers were lower than that of the unfunctionalized poly(ε‐caprolactone). The hydrolytic degradation of the functionalized polymer was also investigated. The result shows the degradation rate was affected by the presence of oleic acid derivatives in the polymer molecule. The lipid‐functionalized polymers synthesized by the metal‐free polymerization systems seem to be suitable biodegradable polyesters for use in biomedical and pharmacological applications. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011