共查询到20条相似文献,搜索用时 78 毫秒
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黑龙江科技学院以过氧化苯甲酰为引发剂,选用甲基丙烯酸为接枝聚合单体,对环氧树脂进行改性。改性后的环氧树脂水分散性增强,产品稳定性提高,能够用于制备水溶性和水乳型的环氧树脂聚合物。水性环氧树脂具有环保、安全等优点,尤其适用于潮湿施工面上的粘接作业,此外,其粘接性能及耐化学腐蚀性能优异。 相似文献
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表面光接枝主要是用芳酮引发有机材料产生自由基,从而引发单体聚合产生表面接枝链。表面光接枝应用领域广泛.可用于聚合材料的表面改性以及表面功能化。综述了紫外光引发接枝改性聚合物表面的研究进展,包括光接枝聚合机理、改性方法、影响因素等,并对其应用前景及研究方向进行了介绍。 相似文献
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将表面活性剂接枝到聚氨酯改性环氧树脂主体上,制备水性聚氨酯改性环氧树脂固化剂,配制的水性环氧地板涂料性能优良。讨论了TDI用量对固化剂性能和涂膜性能的影响。 相似文献
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As‐received multiwalled carbon nanotubes (MWCNTs) were first treated by a 3 : 1 (v/v) mixture of concentrated H2SO4/HNO3 and further functionalized by ethylenediamine/dicyclohexylcarbodiimide/tetrahydrofuran solution. MWCNT/epoxy nanocomposites were prepared. Their cure behaviors were investigated by dynamic differential scanning calorimetry. Quantitative analysis of the activation energy as a function of the degree of curing was carried out by the Flynn‐Wall‐Ozawa method. The fitted multiple regression equations for values of the activation energy of different systems were obtained. MWCNTs have the retardation effect on the cure reaction of epoxy resin, while the functional groups on the surface of amine‐modified MWCNTs could accelerate the cure reactions. Thermal stability was studied by thermogravimetric analysis. The filling of amine‐modified MWCNTs is beneficial to lower the cure activation energy and improve thermal stability of the nanocomposite. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
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Xiao‐Hua Zhang Zheng‐Hua Zhang Wei‐Jian Xu Fan‐Cai Chen Jian‐Ru Deng Xiao Deng 《应用聚合物科学杂志》2008,110(3):1351-1357
The toughness of cycloaliphatic epoxy resin 3,4‐epoxycyclohexylmethyl‐3′,4′‐epoxycyclohexane carboxylate (ERL‐4221) has been improved by using multiwalled carbon nanotubes (MWCNTs) treated by mixed acids. The MWCNT/ERL‐4221 composites were characterized by Raman spectroscopy and their mechanical properties were investigated. A significant increase in the tensile strength of the composite from 31.9 to 55.9 MPa was obtained by adding only 0.05 wt % of MWCNTs. And a loading of 0.5 wt % MWCNTs resulted in an optimum tensile strength and cracking energy, 62.0 MPa and 490 N cm, respectively. Investigation on the morphology of fracture surface of the composites by field emission scanning electron microscopy demonstrated the crack pinning‐front bowing and bridging mechanisms of toughening. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
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Thu Ha Thi Vu Thu Trang Thi Nguyen Manh Hung Do Minh Tu Pham Duy Hung Bui 《Journal of Sulfur Chemistry》2017,38(3):264-278
Composites of carbon nanotubes – titanate nanotubes (MWNTs/ TNTs) – were successfully synthesized by the hydrothermal reaction process. The morphology of the MWNTs/TNTs composites was observed by transmission electron microscopy. Fourier transform infrared spectroscopy was used to characterize the molecular interactions between TNTs and MWNTs in the composites. The X-ray diffraction of TNTs and MWNTs/TNTs composites exhibited the existence of titanate phase (100), (102), (020) and (422). The charge recombination of MWNTs/TNTs composites was examined by photoluminescence spectrum. The photocatalytic activity of TNTs and MWNTs/TNTs composites was evaluated on the basis of the model oxidation reaction of H2S. 相似文献
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Ryan J. Sager Patrick J. Klein Daniel C. Davis Dimitris C. Lagoudas Graham L. Warren Hung‐Jue Sue 《应用聚合物科学杂志》2011,121(4):2394-2405
The Mode I interlaminar fracture behavior of woven carbon fiber/epoxy composite laminates incorporating partially cured carbon nanotube/epoxy composite films has been investigated. Laminates with films containing carbon nanotubes (CNTs) in the as‐received state and functionalized with polyamidoamine were evaluated, as well as laminates with neat epoxy films. Double‐cantilever beam (DCB) specimens were used to measure GIc, the critical strain energy release rate (fracture toughness) versus crack length. Post‐fracture microscopic inspection of the fracture surfaces was performed. Results show that initial fracture toughness was improved with the amino‐functionalized CNT/epoxy interleaf films, but the important factor appears to be the polyamidoamine functionalization, not the CNTs. The initial fracture toughness remained relatively unaffected with the incorporation of neat epoxy and as‐received CNT/epoxy interleaf films. Plateau fracture toughness was unchanged with the use of functionalized CNT/epoxy interleaf films, and was reduced with the use of neat epoxy and as‐received CNT/epoxy interleaf films. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 相似文献
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二乙烯三胺改性碳纳米管对环氧树脂纳米复合材料力学性能影响研究 总被引:2,自引:1,他引:1
采用二乙烯三胺(DETA)对碳纳米管(MWNTs)进行改性,并用X射线衍射(XRD)和傅里叶变换红外光谱(FTIR)对其进行表征。发现DETA被有效地包覆在MWNTs表面。并将改性前后的MWNTs与环氧树脂进行复合,采用浇铸成型法制备了MWNTs/环氧树脂纳米复合材料,测试其力学性能,并采用透射电镜(TEM)研究其分散性,扫描电镜(SEM)对其断口进行了分析研究。结果表明,少量的改性MWNTs可以使复合材料的力学性能提高,具有明显的增韧作用。当MWNTs的含量为0.6%时,纳米复合材料的冲击强度与纯环氧体系相比,提高幅度达400%以上,弯曲强度和弯曲模量的提高幅度均达到了100%以上。 相似文献
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Chih‐Chun Teng Chen‐Chi M. Ma Shin‐Yi Yang Kuo‐Chan Chiou Tzong‐Ming Lee Chin‐Lung Chiang 《应用聚合物科学杂志》2012,123(2):888-896
The well dispersed multiwalled carbon nanotube (MWCNT)/epoxy composites were prepared by functionalization of the MWCNT surfaces with glycidyl methacrylate (GMA). The morphology and thermal properties of the epoxy nanocomposites were investigated and compared with the surface characteristics of MWCNTs. GMA‐grafted MWCNTs improved the dispersion and interfacial adhesion in epoxy resin, and enhanced the network structure. The storage modulus of 3 phr GMA‐MWCNTs/epoxy composites at 50°C increased from 0.32 GPa to 2.87 GPa (enhanced by 799%) and the increased tanδ from 50.5°C to 61.7°C (increased by 11.2°C) comparing with neat epoxy resin, respectively. Furthermore, the thermal conductivity of 3 phr GMA‐MWCNTs/epoxy composite is increased by 183%, from 0.2042 W/mK (neat epoxy) to 0.5781 W/mK. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 相似文献
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Polyethylene multiwalled carbon nanotube composites 总被引:4,自引:0,他引:4
Tony McNally Petra Pötschke Michael Murphy Steven E.J. Bell Daniel Bein John Paul Quinn 《Polymer》2005,46(19):8222-8232
Polyethylene (PE) multiwalled carbon nanotubes (MWCNTs) with weight fractions ranging from 0.1 to 10 wt% were prepared by melt blending using a mini-twin screw extruder. The morphology and degree of dispersion of the MWCNTs in the PE matrix at different length scales was investigated using scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM) and wide-angle X-ray diffraction (WAXD). Both individual and agglomerations of MWCNTs were evident. An up-shift of 17 cm−1 for the G band and the evolution of a shoulder to this peak were obtained in the Raman spectra of the nanocomposites, probably due to compressive forces exerted on the MWCNTs by PE chains and indicating intercalation of PE into the MWCNT bundles. The electrical conductivity and linear viscoelastic behaviour of these nanocomposites were investigated. A percolation threshold of about 7.5 wt% was obtained and the electrical conductivity of PE was increased significantly, by 16 orders of magnitude, from 10−20 to 10−4 S/cm. The storage modulus (G′) versus frequency curves approached a plateau above the percolation threshold with the formation of an interconnected nanotube structure, indicative of ‘pseudo-solid-like’ behaviour. The ultimate tensile strength and elongation at break of the nanocomposites decreased with addition of MWCNTs. The diminution of mechanical properties of the nanocomposites, though concomitant with a significant increase in electrical conductivity, implies the mechanism for mechanical reinforcement for PE/MWCNT composites is filler-matrix interfacial interactions and not filler percolation. The temperature of crystallisation (Tc) and fraction of PE that was crystalline (Fc) were modified by incorporating MWCNTs. The thermal decomposition temperature of PE was enhanced by 20 K on addition of 10 wt% MWCNT. 相似文献
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The aim of this article was to elucidate the basic relationships between processing conditions and the mechanical and electrical properties of multiwalled carbon nanotube reinforced polymer composites. In conventional chopped fiber reinforced polymer composites, uniform distributions of fibers throughout the matrix are critical to producing materials with superior physical properties. Previous methods have dispersed carbon nanotubes by aggressive chemical modification of the nanotubes or by the use of a surfactant prior to dispersion. 1 , 2 Here, ultrasonic energy was used to uniformly disperse multiwalled nanotubes (MWNTs) in solutions and to incorporate them into composites without chemical pretreatment. Polystyrene (PS) solutions containing MWNTs were cast and spun to yield thin film MWNT composites. The rheology of PS/MWNT suspensions was modeled using the Carreau equation. MWNTs were found to align at the shear rates generated by the spin casting process. The tensile modulus and strain to failure of samples compared well to classical micromechanical models, increasing with MWNT loading. The composite films showed lower strains at the yield stress than neat PS films. The presence of MWNTs at 2.5 vol % fraction approximately doubles the tensile modulus, and transforms the film from insulating to conductive (surface resistivity, ρ, approaching 103 Ω/□). © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2660–2669, 2002 相似文献