热致感应型形状记忆高分子材料与纤维

介绍了热致感应型形状记忆高分子材料的机理、制备方法及其应用,重点介绍了热致感应型形状 记忆纤维的混纺和后整理生产技术及国内外研究发展状况。指出今后应大力开发热致感应形状记忆纤维的 直接纺丝生产技术,提高纤维的形变回复力及尺寸稳定性,纤维的应用前景看好。     

形状记忆材料杜仲胶/天然橡胶/低密度聚乙烯的研究

采用天然橡胶(NR)、低密度聚乙烯(LDPE)对杜仲胶进行共混改性,并以力学性能和形状记忆性能为衡量指标对配方进行筛选。结果表明:改性材料的力学性能和形状记忆性能明显提高;综合比较,性能达到最优化时胶料的最佳配比是m(LDPE)∶m(NR)∶m(杜仲胶)=20∶60∶20。     

Thin polymer films based on poly(vinyl alcohol) containing graphene oxide and reduced graphene oxide with functional properties

In this article, the effect of the addition of graphene oxide (GO) and reduced graphene oxide (rGO) on the mechanical properties, thermal stability, and electrical conductivity of polyvinyl alcohol (PVA) has been investigated. Different weight percentages of nanofillers ranging from 0.5 to 5 wt% have been combined with PVA. The ultrasonic technique has been applied to disperse nanofillers in the PVA solution. The nanocomposite films have been prepared via solution casting technique and the dispersion of nanofillers into the PVA has been studied through optical microscopy. The microstructure, crystallization behavior, and interfacial interaction were characterized through X-ray diffraction and Fourier transform infrared spectroscopy. Differential scanning calorimetry (DSC) and thermogravimetric analysis have been applied to study the thermal properties of the prepared nanocomposites. The DSC results revealed that the crystallization temperature and melting temperature were enhanced in the presence of GO nanofiller. Besides, the tensile strength at break was improved along with the addition of GO; however, elongation at break for PVA/GO and PVA/rGO was diminished. Moreover, all specimens showed insulating behavior and the only sample was electrically conducting, which contain a high amount of rGO (5 wt%).     

Design and development of graphene oxide/shape memory nanocomposite based on hexamethylene diisocyanate mixing segment

Shape memory polymers are remarkable materials renowned for their distinctive ability to fix and recover their original shape in response to specific stimuli. However, the lower shape fixity (SF) of conventional thermally triggered shape memory polyurethane (SMPU) has limited its broad application potential. This study investigates the transformative influence of graphene oxide (GO) nanofillers when incorporated into a linear diisocyanate-based mixing segment SMPU (SMPU-GO). The lower SF issue of SMPU is ingeniously addressed by leveraging the interactive properties of GO with the 4,4′-methylene bis-phenyl diisocyanate hard segment and the introduction of additional physical cross-links via hexamethylene diisocyanate mixing segment. At 1 wt.% GO incorporation, the modulus increased by 178%, an 8% increase in tensile strength, while the elasticity was maintained. Excellent improvement in SF and shape recovery (SR) was attained at 1 wt.% GO incorporated SMPU, and the SMPU nanocomposite showed the highest SF (65%) and SR (100%) at 70°C temperature and 50% strain.     

Development of polyaniline/zinc oxide nanocomposite impregnated fabric as an electrostatic charge dissipative material

The paper presents the electrostatic charge dissipative performance of conducting polymer nanocomposite impregnated fabric based on polyaniline (PANI) and zinc oxide nanoparticles (ZnO NPs). Conducting polymer nanocomposites (PANI‐ZnO NPs) were synthesized by in situ chemical oxidative polymerization of aniline by using sodium dodecyl sulfate as surfactant and HCl as dopant. Coating of PANI‐ZnO nanocomposites on the cotton fabric was carried out during polymerization. The interaction of ZnO NPs with the PANI matrix was determined by Fourier transform infrared spectra (FTIR), TGA, XRD, scanning electron Microscopy (SEM), high resolution transmission electron microscopy (HRTEM) and conductivity measurements. The conductivity of PANI‐ZnO NP coated fabric was found to be in the range 10^?3 ? 10^?6 S cm^?1 depending on the loading concentration of ZnO NPs in the polymer matrix. TEM and HRTEM images showed that the PANI‐ZnO nanocomposites had an average diameter of 25–30 nm and were nicely dispersed in the polymer matrix. Antistatic performance of the nanocomposite impregnated fabric was investigated by static decay meter and John Chubb instrument. The static decay time of the film was in the range 0.5 ? 3.4 s on recording the decay time from 5000 V to 500 V. This indicated that the nanocomposite based on PANI‐ZnO nanocomposites has great potential to be used as an effective antistatic material. © 2015 Society of Chemical Industry     

Interpenetrating polymer network and nanocomposite IPN of polyurethane/epoxy: a review on fundamentals and advancements

This article presents state-of-the-art review on interpenetrating polymer network (IPN) formation by polyurethane/epoxy (PU/EP). PU is thermoplastic polymer with fine mechanical strength, chemical resistance, processability, and thermal stability. EP resins also possess unique chemical and physical properties, though it is rigid and brittle. Amalgamation of two polymers have resulted in improved mechanical, thermal, damping, and glass transition behavior. PU/EP IPN and nanocomposite containing carbon nanotube, graphene oxide, nanodiamond, nanoclay, and various other nanoparticles have been discussed. Commercial implication and future prospects of PU/EP-crosslinked network and nanocomposite IPN are foreseen in high-performance engineering materials, automotive and aerospace, and biomedical devices.     

High-performance polymer solar cells with radiation-induced and reduction-controllable reduced graphene oxide as an advanced hole transporting material

We demonstrate that radiation-induced reduced graphene oxide (RrGO) can efficiently function as a hole transporting layer (HTL) for polymer solar cells (PSCs). The solution-processable RrGO was simply obtained by γ-ray irradiation of a graphene oxide (GO) solution dispersed in ethanol and water. Changes in the chemical composition, conductivity, work-function, and morphology in RrGO films that resulted from the increase in absorbed dose amounts were systematically investigated. In addition, GO, a conventional hydrazine-based GO (CRGO), and the RrGOs were also studied as HTLs in PSCs, and as a result, the RrGO-based PSC showed more enhanced PSC performance than those of GO and CRGO due to better conductivity than GO and better film morphology and work function than CRGO. More importantly, the best RrGO-based PSC showed comparable cell performance to the conventional poly (3,4-ethylenedioxythiophene):poly (styrene sulfonate) (PEDOT:PSS)-based PSC and better stability than PEDOT:PSS, indicating that the use of the RrGO is more desirable as an efficient HTL than the PEDOT:PSS for high-performance and high-stability PSCs.     

Recent advancement in self-healing graphene polymer nanocomposites,shape memory,and coating materials

ABSTRACT

Recently, self-healing polymeric materials has garnered much attention due to their ability to prolong materials shelf-life. Graphene, as a formidable nanoparticle, has garnered great interests due to accruable superior properties in polymer nanocomposites (PNC). Application of organic coatings is the most available, and cost-efficient technique of enhancing the shelf-life of metallic structures. Shape memory polymeric materials are capable of being deformed, and arranged into a temporary shape, while also recovering their original configuration on exposure to external stimulation. Hence, the advent of self-repairing graphene PNC, coatings, and polymeric shape memory materials has enlarged the applications scope of these materials.     

Strontium incorporated hydroxyapatite/hydrothermally reduced graphene oxide nanocomposite as a cytocompatible material

Hydroxyapatite (HA)/reduced graphene oxide (rGO) composites with different mol% of strontium and 1?wt% of GO were fabricated through a green hydrothermal reduction method and this combination has been reported for the first time. All the synthesized composites had strontium incorporated onto the crystal structure of HA as can be substantiated from XRD and FTIR. This paper also discusses a possible role of surface and pore characteristics on the in vitro cytocompatibility and the contribution of graphene oxide in directing the nucleation points resulting in dispersed strontium incorporated hydroxyapatite (SHA) based on P-31 NMR and TEM studies. In addition, a reasonable speculation also has been made to correlate the cytocompatibility with the selective occupancy of strontium ions in the apatite lattice. The in vitro cytocompatibility of SHA/rGO composites (SHAG) has been evaluated using cell proliferation tests with MG-63 cells, under a wider range of concentrations (1000–7.8?µg/ml) and by varying Sr/(Ca+Sr) molar ratio. SHAG with strontium substitution of 10?mol% exhibited the maximum viability among the samples tested. These results suggest that the SHAG composites will be a promising material for biomedical application.     

Synthesis and properties of shape memory graphene oxide/polyurethane chemical hybrids

Graphene oxide modified chemically with allyl isocyanate (iGO) was incorporated in various amounts into acrylate‐terminated polyurethane (PU) via UV curing. The effects of this incorporation on the morphological, mechanical, dynamic mechanical, thermal and shape memory properties of the resulting hybrids were examined. The iGO nanoparticles incorporated into the PU chains acted as both multifunctional crosslinks and reinforcing fillers, and the effects were most pronounced at low iGO contents (0.5 and 1.0 wt%). Consequently, the glassy and rubbery state moduli, yield strength, glass transition temperature, shape fixity and shape recovery ratios were increased on adding up to 1 wt% iGO. At higher iGO loadings, the values of most of these properties decreased due to aggregation and the auto‐inhibition of allyl compounds. © 2013 Society of Chemical Industry     

Novel method to measure the shear strength of exfoliated montmorillonite/polymer nanocomposite films

Shear fracture of exfoliated montmorillonite/poly(methyl acrylate‐co‐methyl methacrylate) (MMT/P(MA‐co‐MMA)) nanocomposite films fabricated via soap‐free emulsion polymerization was studied using a unique test fixture that is capable of controlling the inclined angle between the loading axis and the shear fracture plane. It was found that fracture of the films depended on both shear and normal stresses and could be described by the Mohr–Coulomb criterion. The effects of MMT content on the intrinsic shear strength (i.e. the shear strength at zero normal stress) τ_s were also examined. The obtained τ_s increased from 1.66 to 2.78 MPa as 1 wt% MMT was incorporated into P(MA‐co‐MMA) and then increased almost linearly to 5.32 MPa when the content of MMT increased to 15 wt%. Also, the fracture‐surface morphology of the composite film depended on both the MMT content and the inclined angle (and hence the normal‐to‐shear stress ratio). For low MMT contents and low normal‐to‐shear stress ratios, striations normal to the shear direction appeared on the fracture surface. As the MMT content or the stress ratio increased, the fracture surface became rough accompanied by the presence of interfacial micro‐cracking between MMT nanoplatelets and the matrix. With further increase in MMT content and high stress ratio, the MMT nanoplatelets were compressed into large flakes on the fracture surface. Copyright © 2011 Society of Chemical Industry     

High reversible capacity of SnO2/graphene nanocomposite as an anode material for lithium-ion batteries

A gas–liquid interfacial synthesis approach has been developed to prepare SnO₂/graphene nanocomposite. The as-prepared nanocomposite was characterized by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, and Brunauer–Emmett–Teller measurements. Field emission scanning electron microscopy and transmission electron microscopy observation revealed the homogeneous distribution of SnO₂ nanoparticles (2–6 nm in size) on graphene matrix. The electrochemical performances were evaluated by using coin-type cells versus metallic lithium. The SnO₂/graphene nanocomposite prepared by the gas–liquid interface reaction exhibits a high reversible specific capacity of 1304 mAh g⁻¹ at a current density of 100 mA g⁻¹ and excellent rate capability, even at a high current density of 1000 mA g⁻¹, the reversible capacity was still as high as 748 mAh g⁻¹. The electrochemical test results show that the SnO₂/graphene nanocomposite prepared by the gas–liquid interfacial synthesis approach is a promising anode material for lithium-ion batteries.     

Magnetically separable Fe3O4/graphene oxide nanocomposite: An efficient heterogenous catalyst for spirooxindole derivatives synthesis

Heterocyclic compounds such as spirooxindole, with five rings containing nitrogen, have an important role in the realm of medicine. This study aims to synthesize the spirooxindole derivative compounds using Fe₃O₄/graphene oxide (GO) nanocomposite as the catalyst. The GO sample was synthesized by Hummers' method, followed by the insertion of Fe₃O₄ into the graphene oxide layers by the co-precipitation method. Both XRD and FTIR analyses reveal that GO and Fe₃O₄/GO samples have been successfully formed. SEM-EDX micrograph supported by TEM image indicates that the Fe₃O₄ nanoparticles in the composite have excellent dispersibility, attributable to the existence of the GO sheets. The evaluation of the ability of Fe₃O₄/GO as a catalyst in the synthesis of spirooxindole derivatives was carried out by the one-pot three-component method. The reaction yield shows that Fe₃O₄/GO was a suitable and reusable catalyst in this reaction.     

Reduced graphene oxide reinforced PET/PBT nanocomposites: Compatibilization and characterization

This research work focused on the effects of different compatibilizers on the properties of reduced graphene oxide (rGO) reinforced poly(ethylene terephthalate) (PET)/poly(butylene terephthalate) (PBT) nanocomposites. The samples were prepared via melt compounding and injection molding methods. The Joncryl and glycidyl isooctyl polyhedral oligomeric silsesquioxane (GPOSS) were used as compatibilizers at different loading levels (0.5%-4%). The structural, thermal, mechanical, morphological, and electrical properties of the nanocomposites were investigated. The Fourier transform infrared analysis results revealed that no significant interaction was observed when GPOSS was added. On the other hand, there were more obvious changes in the peaks of the nanocomposite containing Joncryl. The thermal results showed that the compatibilizer addition caused small changes while rGO addition did not considerably affect the thermal stability of blend. The glass transition temperature of the nanocomposite significantly decreased with the addition of GPOSS. The tensile test indicated that compatibilizers improved the mechanical performance of PET/PBT/rGO nanocomposite.     

Synthesis of CuGeO3/reduced graphene oxide nanocomposite by hydrothermal reduction for high performance Li-ion battery anodes

Nowadays, Lithium-ion batteries (LIBs) are prevalently applied in numerous areas, leading to increasing demand of innovative electrodes with high specific capacities. An advanced CuGeO₃/reduced graphene oxide (rGO) structure is designed and fabricated as the anode material taking the advantage of considerable capacity offered by CuGeO₃ and stable framework constructed by rGO. The as-prepared CuGeO₃ with 30 wt% GO addition exhibits the best electrochemical performance. Specifically, a reversible charge capacity of 909 mAh·g⁻¹ with high coulombic efficiency of 91.49% at the current density of 100 mA g⁻¹ after 200 cycles is demonstrated, and the rate capacity retains 747.6 mAh·g⁻¹ with 91.59% capacity retention. These results indicate that the CuGeO₃/rGO composite holds great potential in next-generation LIBs.     

阳离子聚合物/膨润土纳米复合吸附材料的性能及对红色染料的脱色

利用阳离子聚合物-聚环氧氯丙烷二甲胺为插层剂,采用 “有机高聚物溶液直接插层复合法”制备了一系列阳离子聚合物聚环氧氯丙烷二甲胺/膨润土纳米复合吸附材料,经特性分析表明,经聚环氧氯丙烷二甲胺插层复合后的膨润土比表面积显著增加,表面电性由负值变为正值,颗粒的聚集程度增加,有较好的吸附和沉降性能.在此基础上,研究了还原大红R、分散大红S-R、活性艳红K-2BP等红色染料在复合膨润土上的吸附行为.结果表明,聚环氧氯丙烷二甲胺/膨润土对三种染料的吸附脱色能力明显大于钠基膨润土,平衡吸附量q_e与平衡浓度C_e之间的关系均符合Langmuir和Freundlich等温吸附模型,吸附动力学行为遵循Langmuir方程所述规律.     

Synthesis of MnOx/reduced graphene oxide nanocomposite as an anode electrode for lithium-ion batteries

We report the high performance of the manganese oxide/reduced graphene oxide (MnOx/rGO) nanocomposite as an anode electrode of a lithium-ion battery. The composite is synthesized by a low temperature (83 °C) chemical solution reaction, and shows relatively high specific capacities (660 mAh g⁻¹) after 50 cycles. For MnOx/rGO composites, the cycling stability is increased remarkably as compared to that seen with individual MnOx, and this is due to the synergistic effects of both the components in the composite. The rGO acts as a conductive buffer layer that suppresses the volume change of MnOx, and simultaneously promotes the conductivity of MnOx. The functional groups of graphene oxide facilitate MnOx formation at low temperature, and this retains the MnOx-graphene oxide connection, thus improving the capacity and cycling stability.     

Indole‐based polymer and its silver nanocomposite as advanced antibacterial agents: synthetic path,kinetics of polymerization and applications

Atom transfer radical polymerization of 1‐allylindole‐3‐carbaldehyde (AIC) was studied by employing 2‐bromoisobutyryl bromide as initiator in toluene. It led to controlled radical polymerization of AIC, with an increase of molecular weight along with the conversion of the monomer, and a relatively narrow molar mass distribution was obtained, as determined by gel permeation chromatography. The living nature of poly(1‐allylindole‐3‐carbaldehyde) (PAIC) was confirmed by the chain extension polymerization whereas ¹H NMR analysis showed that the major population of PAIC retained the chain‐end functional group. PAIC and its silver nanocomposite were found to be biologically active against some tested bacterial pathogens. Minimum inhibitory concentration tests revealed that PAIC exhibited antibacterial activity against Staphylococcus aureus, Proteus mirabilis and Klebsiella pneumonae whereas PAIC/Ag nanocomposite showed antibacterial activity against Enterococcus faecalis and K. pneumonae. © 2012 Society of Chemical Industry     

Characterization and performance of dodecyl amine functionalized graphene oxide and dodecyl amine functionalized graphene/high‐density polyethylene nanocomposites: A comparative study

Dodecyl amine (DA) functionalized graphene oxide(DA‐GO) and dodecyl amine functionalized reduced graphene oxide (DA‐RGO) were produced by using amidation reaction and chemical reduction, then two kinds of well dispersed DA‐GO/high‐density polyethylene (HDPE) and DA‐RGO/HDPE nanocomposites were prepared by solution mixing method and hot‐pressing process. Thermogravimetric, X‐ray photoelectron spectroscopy, Fourier transforms infrared spectroscopy, X‐ray diffractions, and Raman spectroscopy analyses showed that DA was successfully grafted onto the graphene oxide surface by uncleophilic substitution and the amidation reaction, which increased the intragallery spacing of graphite oxide, resulting in the uniform dispersion of DA‐GO and DA‐RGO in the nonpolar xylene solvent. Morphological analysis of nanocomposites showed that both DA‐GO and DA‐RGO were homogeneously dispersed in HDPE matrix and formed strong interfacial interaction. Although the crystallinity, dynamic mechanical, gas barrier, and thermal stability properties of HDPE were significantly improved by addition of small amount of DA‐GO or DA‐RGO, the performance comparison of DA‐GO/HDPE and DA‐RGO/HDPE nanocomposites indicated that the reduction of DA‐GO was not necessary because the interfacial adhesion and aspect ratio of graphene sheets had hardly changed after reduction, which resulting in almost the same properties between DA‐GO/HDPE and DA‐RGO/HDPE nanocomposites. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39803.