原位聚合纳米PZDMA补强POE材料的研究

利用显微镜观察和热分析方法研究了原位聚合纳米聚甲基丙烯酸锌（PZDMA）补强乙烯－α辛烯共聚物（POE）材料（简称PZDMA补强材料）的纳米分散相结合的生成历程和补强机理,探讨了PZDMA补强材料的应力－应变特性及拉伸强度与温度的关系。结果表明,PZDMA补强材料的纳米分散相（聚甲基丙烯酸锌）是硫化过程中ZDMA发生原位聚合反应生成的;PZDMA补强材料强度高的主要原因是纳米PZDMA分散相与POE分子间的物理吸附松驰特性比化学吸附松驰特性好;PZDMA补强材料的应力－应变特性与炭黑补强POE胶料有明显差异,PZDMA补强材料的常温拉伸强度显高于、高温拉伸强度低于炭黑补强POE胶料。     

纳米氮化硅/三元乙丙橡胶复合材料的制备与性能

用甲基丙烯酸锌原位聚合改性纳米氮化硅,再将改性纳米氮化硅填充到三元乙丙橡胶中以制备纳米橡胶复合材料,研究了复合材料的基本力学性能、耐热老化性能、耐油性能和耐磨性能等。结果表明,添加改性的纳米氮化硅在一定程度上提高了三元乙丙橡胶的撕裂强度、扯断伸长率和拉伸强度,邵尔A硬度也小幅上升。当改性纳米氮化硅的添加量为1.0份(质量)时,纳米氮化硅/三元乙丙橡胶复合材料的耐热老化性能和耐油性能有一定程度的提高,其综合性能也达到最佳。用甲基丙烯酸锌原位聚合改性可以改善纳米氮化硅与三元乙丙橡胶基质间的界面作用,提高其在三元乙丙橡胶中的分散效果。     

聚合物—层状硅酸盐纳米复合材料制备及应用

聚合物－层状硅酸盐（ＰＬＳ）纳米复合材料因其优异的性能是目前材料科学研究的热点,简要回顾ＰＬＳ纳米复合材料研究发展的概况,概述ＰＬＳ纳米复合材料的特点,种类,微观结构与物理力学性能,着重介绍ＰＬＳ纳米复合材料的各种制备方法和原理,并从热力学角度对插层复合过程进行了分析,讨论了层状硅酸盐的表面修饰,提出了插层剂的选择原则,展望了ＰＬＳ纳米复合材料的应用前景。     

ZDMA/EPDM复合材料的制备及性能研究

通过一步法合成纳米级甲基丙烯酸锌（ZDMA）,再填充到三元乙丙橡胶（EPDM）中制备纳米橡胶复合材料,研究了复合材料的基本力学性能、耐热老化性能、耐油性能和耐磨性能。结果表明,当纳米级ZDMA的用量为2．0份时,三元乙丙橡胶（EPDM）耐油性能有一定提高,且综合性能达到最佳。     

纳米陶瓷复合材料的制备方法

纳米陶瓷复合材料具有良好的力学性能和优越的高温性能等特性，是当今材料科学研究的重要课题。本文综合国内相关资料对纳米陶瓷昨合材料的制备方法作一简要评述，主要介绍纳米陶瓷复合粉体的制备方法和固体纳米陶瓷复合材料的烧结。     

聚合物/无机纳米粒子复合材料的研究进展

综述了无机纳米氧化物(如SiO2、TiO2、Al2O3)、纳米硅化物(如SiC、Si3N4)和纳米CaCO3作为填充材料对聚合物材料物理、化学、热学、光学、力学及摩擦学性能的改善作用,在聚合物中加入纳米粒子是制备高性能复合材料的重要手段之一。     

纳米TiO2/PP复合材料的研究

研究了纳米TiO2／PP复合材料的力学性能和耐老化性能，实验结果表明，添加1％－2％的纳米TiO2可以明显改善PP材料的抗冲击性能；纳米质量分数在1％－4％范围内对复合材料的拉伸强度几乎没有影响；而添加少量的纳米TiO2可以大大提高PP材料的耐紫外光老化性能，说明纳米TiO2对紫外光有极强的吸收能力。TiO2/PP复合材料具有良好的耐候性，可以提高其户外制品的使用寿命。     

有机聚合物／无机化合物纳米复合阻燃材料研究进展

综述了有机聚合物／无机化合物纳米复合阻燃材料的研究和应用现状。阐述的纳米复合阻燃材料包括有机聚合物／层状硅酸盐纳米复合材料、有机聚合物／碳纳米管纳米复合材料、有机聚合物／二氧化硅纳米复合材料、有机聚合物／石墨纳米复合材料等。与传统无机阻燃剂填充阻燃材料相比,这类新型纳米复合阻燃材料的填料与基体的亲合性、基体的物理力学性能和阻燃性能等均得到改善。     

粘土／丁苯橡胶纳米复合材料的制备和性能

通过两种方法制备了粘土均匀分散于橡胶中的纳米复合材料。电子显微镜显示粘土以单层和多层的形式分散于橡胶基体中,Ｘ－光衍射显示了粘土的晶层间距得到扩充,粘土层间插入了高分子。纳米复合材料具有与用炭黑补强的材料同样的良好性能。     

纳米硫化镉复合材料的研究进展

纳米硫化镉是一种重要的半导体功能材料,当前纳米硫化镉的研究主要集中在纳米材料的制备与生成机理的研究,对于纳米硫化镉与体材料的复合及其优异的化学性能在环境方面的运用研究还比较缺乏。本文综述了近年来国内外关于纳米硫化镉材料和纳米硫化镉复合材料的研究进展。     

Tribological properties of micro‐ and nanoparticles‐filled poly(etherimide) composites

It has been found that nano‐ or microsized inorganic particles in general enhance the tribological properties of polymer materials. In the present study, 5 vol % nano‐TiO₂ or micro‐CaSiO₃ was introduced into a polyetherimide (PEI) matrix composite, which was filled additionally with short carbon fibers (SCF) and graphite flakes. The influence of these inorganic particles on the sliding behavior was investigated with a pin‐on‐disc testing rig at room temperature and 150°C. Experimental results showed that both particles could reduce the wear rate and the frictional coefficient (μ) of the PEI composites under the applied testing conditions. At room temperature, the microparticles‐filled composites exhibited a lower wear rate and μ, while the nano‐TiO₂‐filled composites possessed the lowest wear rate and μ at elevated temperature. Enhancement in tribological properties with the addition of the nano‐particles was attributed to the formation of transfer layers on both sliding surfaces together with the reinforcing effect. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1678–1686, 2006     

Nano Cyclotetramethylene Tetranitramine Particles Prepared by a Green Recrystallization Process

The solubility of cyclotetramethylene tetranitramine (HMX) in four ionic liquids (ILs): 1,3‐dimethylimidazolium dimethylphosphate ([Memim]DMP), 1‐butyl‐3‐methylimidazolium chloride ([Bmim]Cl), 1‐hexyl‐3‐methylimidazolium bromide ([Hmim]Br), and 1‐ethyl‐3‐methylimidazolium tetrafluoroborate ([Emim]BF₄) was investigated. Nano‐HMX were produced particles by spraying [Hmim]Br solution into purified ice water. Finally, the particle size, morphology, crystal phase, impact sensitivity, and thermal decomposition properties of nano‐HMX particles were tested and analyzed. All four ILs could dissolve HMX to a greater or lesser extent in the temperature range from 20 °C to 80 °C. The solubility of HMX in [Hmim]Br at 80 °C is up to 0.7 g mL⁻¹. Recrystallized HMX particles are of polyhedral or spherical shape and 40 to 130 nm in size. X‐ray diffraction indicated that nano‐HMX has a similar crystal structure as raw HMX (β‐form). Compared with raw HMX, the nano‐HMX particles have much lower impact sensitivity. However, they are easier to explode than raw HMX under thermal stimulus due to the lower peak temperature and activation energy.     

聚酰亚胺/纳米氧化硅氧化铝杂化膜的制备

研究了用溶胶凝胶法制得的二氧化硅及三氧化二铝溶胶,将其掺入到聚酰胺酸基体中,得到SiO2-Al2O3/聚酰亚胺杂化膜,并采用FTIR、SEM和TGA表征了所制备的杂化膜的结构微观形态和热性能。结果表明,薄膜材料中SiO2和Al2O3粒子分散均匀,与有机相存在键合,材料热分解温度有所提高。     

A comparative study of synthesis and spark plasma sintering of YAG nano powders by different co-precipitation methods

Pure yttrium-aluminum-garnet (YAG) nano particles were synthesized via normal and reverse co-precipitation methods using nitrate starting solutions and ammonium hydrogen carbonate (AHC) as precipitator agent. The impact of titration method on the phase evolution, thermal behavior, precipitate's composition, morphology and chemical bonds of powders were studied by XRD, TG-DTA, FTIR, FESEM, TEM, EDS and BET analysis. The results revealed that in the normal method, the precipitates were composed of relatively dense particles compared with more homogenous fluffy precipitates with higher carbonate content obtained by the reverse method. The precursors achieved by the reverse method formed less agglomerated and smaller size YAG powders after calcination at 900?°C. Calcined nano powders were processed by spark plasma sintering (SPS) technique at 1350?°C for 10?min without any sintering aids or dispersive agents. The sintering of both powders led to a highly dense and fine submicron-structured YAG ceramic. However, the YAG ceramic produced by SPS of reverse co-precipitated nano powders showed higher transparency (43% at 680?nm and 58% in near-infrared range) and finer micro-structure (about 210?nm in grain size) as compared with normal co-precipitated nano particles.     

Enhancement of electrical properties of anisotropically conductive adhesive joints via low temperature sintering

The electrical properties of anisotropically conductive adhesives (ACAs) joints through low temperature sintering of nano silver (Ag) particles were investigated and compared with that of the submicron‐sized Ag‐filled ACA and lead‐free solder joints. The nano Ag particles used exhibited sintering behavior at significantly lower temperatures (<200°C) than at the bulk Ag melting temperature (960°C). The sintered nano Ag particles significantly reduced the joint resistance and enhanced the current carrying capability of ACA joints. The improved electrical performance of ACA was attributed to the reduced interfaces between the Ag particles and the increased interfacial contact area between nano Ag particles and bond pads by the particle sintering. The reduced joint resistance was comparable to that of the lead‐free (tin/3.5 silver/0.5 copper) metal solder joints. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1665–1673, 2006     

Effect of microwave sintering on the microstructure and mechanical properties of AA7075/B4C/ZrC hybrid nano composite fabricated by powder metallurgy techniques

AA7075 + 6%B4C+3%ZrC nano hybrid composite was successfully fabricated, with nano reinforcements composition in AA7075 alloy selected based on previous investigation, to achieve better mechanical performance. Two different sintering techniques, namely conventional and microwave, were implemented to determine the effect on microstructural and mechanical properties. Microstructural investigation was performed with the help of W-SEM. Tensile, compression, and hardness were measured with the help of UTM and Vickers microhardness machine. Porosity was calculated by using Archimedes principle. It was observed that the added nano ZrC particles formed agglomerates and the B₄C particles were distributed homogenously. Composites processed by microwave sintering showed excellent mechanical properties compared to the conventionally sintered composites. No intermetallic compounds were detected in microwave sintered composites through XRD analysis, indicating strong and clean interface bonds between matrix and reinforcement particles. High strain to fracture value of 12.24% was noted in microwave sintered nano hybrid composite, while it was 6.12% for conventional sintered one. Fractography revealed no peeling action of reinforcements from the matrix material, and the mode of failure was brittle. It was concluded that, while fabricating nano range hybrid composites, the implementation of advanced sintering technique (microwave sintering) with low sintering temperatures and low sintering times with internal heat generations, helps in eliminating defects that may develop because of high surface energies of nano range reinforcements.     

Preparation and characterization of poly(styrene butylacrylate) latex/nano‐ZnO nanocomposites

Poly(styrene butylacrylate) latex/nano‐ZnO composites were prepared by blending poly(styrene butylacrylate) latex with a water slurry of nano‐ZnO particles, and the effects of certain parameters, such as particle size, dispersant type, dispersing time and others, on the dispersibility, mechanical properties, ultraviolet (UV) shielding and near infrared (NIR) shielding were investigated with transmission electron microscopy (TEM), an Instron testing machine, dynamic mechanical analysis and ultraviolet‐visible‐near infrared (UV‐VIS‐NIR) spectrophotometry. TEM observation showed that dispersants with long chains are better than those with short chains at enhancing the dispersibility of nano‐ZnO particles in a matrix; extending dispersing time also improves the dispersibility of nano‐ZnO particles in a matrix. Instron tests showed that the nanocomposite polymers embedded with nano‐ZnO particles had much higher tensile strength than the corresponding composite polymers with micro‐ZnO particles. As the nano‐ZnO content increased, the temperature of glass transition (T_g) of the nanocomposite polymer embedded with 60 nm ZnO particles first increased then decreased, but 100 nm ZnO and micro‐ZnO particles seemed to have no influence on the T_g of the composite polymers. The better dispersibility of nano‐ZnO particles resulted in higher T_g values. Increasing nano‐ZnO content or dispersibility could enhance the UV shielding properties of the nanocomposite polymers, and 60 nm ZnO particles could more effectively shield UV rays than 100 nm ZnO particles. Micro‐ZnO particles basically had no effect on the UV absorbance of the composite polymers. A blue‐shift phenomenon was observed at 365 nm when nano‐ZnO particles were present in the nanocomposite polymers. NIR analysis indicated that as nano‐ZnO content increased, the NIR shielding of the nanocomposite polymers increased, but the NIR shielding properties seemed to be more influenced by particle size than by the nano‐effect. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1923–1931, 2003     

Morphology and properties of PET/PA‐6/SiO2 ternary composites

A kind of hydrophilic nano‐SiO₂ was applied to poly(ethylene terephthalate)/polyamide‐6 (PA‐6) blends. Melt‐blended composites were prepared at various component ratios and different nano‐SiO₂ levels. Mechanical, morphological, dynamic mechanical, and thermal tests were carried out to characterize the properties, morphology, and compatibilization of the composites. Increased impact strength, tensile strength, and modulus were observed by adding nano‐SiO₂ particles in the blends. The nano‐SiO₂ particles were found to be preferentially dispersed in PA‐6, resulting in an increase of glass transition temperature and crystallization of PA‐6. The mechanism of morphology and properties changes was discussed based on the selective dispersion of nano‐SiO₂ particles in the blends. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2288–2296, 2007     

可聚合表面活性剂在磁性纳米材料制备中的应用(英文)

以马来酸酐和正十八醇为原料合成了可聚合表面活性剂马来酸单十八酯,并用其改性Fe3O4纳米磁粉.用改性纳米磁粉制备了苯乙烯基可聚合磁流体,并通过本体聚合获得了磁性纳米复合材料.透射电镜分析结果表明,直径约7 nm的Fe3O4纳米颗粒在磁流体和复合材料中分散均匀,无明显团聚现象;红外光谱分析结果表明,磁粉表面包覆的马来酸单十八酯和苯乙烯基质发生了共聚.差示扫描量热、热重及凝胶渗透色谱分析结果表明,与相间条件聚合的聚苯乙烯(PS)相比,复合材料的玻璃化转变温度和去除磁粉后的相对分子质量明显降低,但热稳定性比相同条件下聚合的PS有明显提高,这说明可聚合表面活性剂和活性PS链之间形成了共价键,从而增强了Fe3O4纳米颗粒与基质的相互作用.     

Characterization of the fracture behavior and viscoelastic properties of epoxy-polyamide coating reinforced with nanometer and micrometer sized ZnO particles

The mechanical and viscoelastic properties of an epoxy-polyamide coating containing nano and micro sized ZnO particles were studied. The nanocomposites were prepared at different loadings of the nano sized ZnO particles. The composites were also prepared using micro sized ZnO particles at different lambdas (lambda (λ) = PVC/CPVC). The optical properties of each nanocomposite were studied by UV–vis technique. Dynamic mechanical thermal analysis (DMTA) and micro-Vickers were used to investigate the mechanical properties of the composites. The viscoelastic properties of the composites were studied by a tensile test. The fracture morphologies of the composites were studied by a scanning electron microscope (SEM). An increase in Tg together with a decrease in cross-linking density of the composites was obtained when the coating was reinforced with the micro sized ZnO particles. On the other hand, the Tg and cross-linking density of the composites were decreased using nano sized ZnO particles. It was also found that, the Young's modulus and the fracture energy of the coating were decreased using micro and nano sized ZnO particles. The greater toughness as well as fracture energy of the composite was obtained when it was reinforced with the nano sized ZnO particles. The curing behavior of the epoxy coating was affected in the presence of the micro and nano sized ZnO particles.