抗静电模压成型热固性复合材料的制备与性能研究

以不饱和聚酯树脂为原料,研究抗静电剂炭黑用量对热固性复合材料力学性能和抗静电性能的影响。结果表明:当炭黑含量1.0%时,复合材料的力学性能和抗静电性最好。     

Preparation and properties of alumina-ceria nano-nano composites

Alumina-ceria composites were prepared by the calcination in air of gels obtained by homogeneous precipitation from dilute chloride and nitrate solutions, followed by either microwave treatment, autoclave treatment or air-drying. Microwave treatment and air-drying of the gels yielded amorphous powders whereas autoclave treatment yielded well-crystallised boehmite. The phase evolution during calcination was investigated by in-situ X-ray diffraction (XRD) and by differential thermal analysis and thermogravimetry (DTA/TG). The structures of the calcined powder were investigated by transmission electron microscopy (TEM) and high resolution TEM. A variety of morphologies was found depending on the processing route. The calcined microwave treated gels consisted of nano-size particles of ceria in nanostructured transition alumina i.e. a nano-nano composite structure suitable for catalysis applications. In comparison, the calcined autoclave treated gels consisted of a coarser composite of large agglomerates of ceria in transition alumina which, however, was more stable against transformation to alpha alumina at high temperature. Boehmite sols made with the autoclave treated gels were suitable for making thin films by dip-coating. This revised version was published online in September 2006 with corrections to the Cover Date.     

ZnO@RGO复合材料的制备及其吸波性能

随着无线信息技术的飞速发展,电磁干扰问题日益突出,引起了全球的广泛关注.人体长时间暴露于电磁辐射下,会对中枢神经系统、心血管系统和视觉系统等造成不同程度的损伤.解决这一问题的关键在于开发能够吸收电磁波的材料.为了改善还原氧化石墨烯(RGO)的微波吸收性能,采用感应加热的方式成功获得四面体针状氧化锌(ZnO),并通过简单...     

碳纳米管/PLA复合材料制备及性能

采用溶液共混法制备纯化和酸化碳纳米管(CNTs)/PLA(聚乳酸)复合膜, 并对CNTs的分散性以及材料的结晶形态、 电性能和降解性能进行了研究。结果表明, 通过SEM观察到经过酸化处理的CNTs能较好地分散在PLA基体中; 在偏光显微镜下能观察到CNTs起到成核剂的作用, 明显细化了晶粒; 加入少量的酸化CNTs能够提高CNTs/PLA复合材料导电性, 体积电阻率下降了7个数量级; 同时, 酸化CNTs能够提高CNTs/PLA复合材料的降解性。     

阻燃ABS复合材料的制备及热分解性能

以阻燃齐聚物(PSPTR)和酚醛树脂(PF)作为膨胀型阻燃剂(IFR)阻燃丙烯晴-丁二烯-苯乙烯共聚物(ABS), 通过极限氧指数(LOI)和水平垂直燃烧(UL-94)测试研究了阻燃PSPTR-PF/ABS体系的阻燃性能。研究表明, 当PSPTR:PF=1:1(质量比), 总质量分数为30%时, 体系的LOI为28.2%, UL-94达V-1级别。采用热重-红外联用(TG-IR)技术探索了阻燃体系的热性能和热分解历程, 发现PSPTR-PF阻燃剂的加入延缓了ABS的热分解, 提高了ABS的热稳定性能。采用SEM、 XRD和Raman光谱分析了燃烧炭层的形貌和结构。结果表明, PF不仅改善了炭层的致密度, 而且完善了炭层的石墨结构, 最终提高了ABS的阻燃性能。     

有机硅导热复合材料的制备及其性能

采用3,4-二氟苯基双环己基乙烯(ECFB)液晶对碳纳米管进行改性,将改性后的碳纳米管(MWCNTs)作为填料制备有机硅复合材料。利用液晶的取向性,在复合材料固化成型过程中施加电场力,诱使碳纳米管取向。采用FTIR、POM、TEM、导热系数测试等手段对改性碳纳米管及复合材料的形貌、结构、性能进行表征。结果表明,ECFB液晶可以改善碳纳米管在有机硅复合材料中的分散性。导热系数测试表明,当复合材料中碳纳米管的质量分数为11%时,施加电场后的ECFB-MWCNTs/有机硅复合材料导热系数达到1.5112 W/(m·K),是施加电场后的MWCNTs/有机硅复合材料的4倍多,是纯有机硅橡胶的近10倍。     

塑性钛基非晶复合材料的制备及性能

通过铜模喷铸法成功制备了一系列内生β-Ti(Zr, Nb)枝晶增塑的Ti-Zr-Nb-Cu-Be非晶复合材料, 研究了成分对枝晶体积分数及尺寸的影响及其对复合材料力学性能的调节作用。结果表明, Ti₄₈Zr₂₀Nb₁₂Cu₅Be₁₅合金压缩强度达到2061 MPa, 塑性变形高达22.5%, 表现出优异的综合力学性能。 非晶复合材料的塑性不仅与β-Ti(Zr,Nb)枝晶相的体积分数有关, 而且受到枝晶尺寸的强烈影响, 在一定体积分数条件下, 枝晶相的尺寸越大, 对剪切带的阻碍作用越明显, 合金的塑性越高。     

阻燃ABS复合材料的制备及热分解性能

以阻燃齐聚物(PSPTR)和酚醛树脂(PF)作为膨胀型阻燃剂(IFR)阻燃丙烯晴-丁二烯-苯乙烯共聚物(ABS),通过极限氧指数(LOI)和水平垂直燃烧(UL-94)测试研究了阻燃PSPTR-PF/ABS体系的阻燃性能.研究表明,当PSPTR:PF=1∶1(质量比),总质量分数为30％时,体系的LOI为28.2％,UL-94达V-1级别.采用热重-红外联用(TG-IR)技术探索了阻燃体系的热性能和热分解历程,发现PSPTR-PF阻燃剂的加入延缓了ABS的热分解,提高了ABS的热稳定性能.采用SEM、XRD和Raman光谱分析了燃烧炭层的形貌和结构.结果表明,PF不仅改善了炭层的致密度,而且完善了炭层的石墨结构,最终提高了ABS的阻燃性能.     

聚苯并(口恶)嗪/凹凸棒土复合材料的制备与性能

以熔融法制备了聚苯并嚼嗪(BZ)/凹凸棒土(AT)复合材料.利用DSC考察了凹凸棒土的引入对苯并噁嗪单体开环温度的影响.通过透射电镜(TEM)观察了凹凸棒土在基体树脂中的分散情况,并对于复合材料的动态机械性能和耐热性进行了研究.     

Preparation and properties of cast aluminium-ceramic particle composites

A casting technique for preparing aluminium-alumina, aluminium-illite and aluminium-silicon carbide particle composites has been developed. The method essentially consists of stirring uncoated but suitably heat-treated ceramic particles of sizes varying from 10 to 200 m in molten aluminium alloys (above their liquidus temperature) using the vortex method of dispersion of particles, followed by casting of the composite melts. Recoveries and microscopic distribution of variously pretreated ceramic particles in the castings have been reported. Mechanical properties and wear of these composites have been investigated. Ultimate tensile strength (UTS) and hardness of aluminium increased from 75.50 MN m^–2 and 27 Brinell hardness number (BHN) to 93.15 MN m^–2 and 37 BHN respectively due to additions of 3 wt % alumina particles of 100 m size. As a contrast, the tensile strength of aluminium-11.8 wt % Si alloy decreased from 156.89 MN m^–2 to 122.57 MN m^–2 due to the addition of 3 wt % alumina particles of the same size. Adhesive wear rates of aluminium, aluminium-11.8 wt % Si and aluminium-16 wt % Si alloys decreased from 3.62×10^–8, 1.75×10^–8 and 1.59×10^–8 cm³ cm^–1 to 2.0×10^–8, 0.87×10^–8 and 0.70×10^–8 cm³ cm^–1, respectively, due to the additions of 3 wt % alumina particles.Formerly with the Department of Mechanical Engineering, Indian Institute of Science, Bangalore 560 012, India.     

尖晶石/玻璃复合材料的制备和性能研究

采用电子陶瓷工艺制备了一系列玻璃/尖晶石陶瓷复合材料,结果表明:复合材料的介电常数、热膨胀系数和显微硬度随着尖晶石含量的增加而增加,而且材料中硼酸铝的生成对复合材料的介电和热膨胀性能有一定影响。所制备的复合材料具有低的介电常数(5.5~6.5)、低的热膨胀系数(5.3×10-6~5.5×10-6℃-1)和低的烧结温度(≤1000℃),有望用于先进的微电子封装基板材料。     

新型硅橡胶基压阻敏感复合材料制备及其性能研究

以多壁碳纳米管(MWNT)和纳米二氧化硅作为助填料,采用三辊研磨机制备了(MWNT-SiO2)/RTV复合材料,研究其压阻和介电性能.结果表明,纳米SiO2经KH570改性,其在基体中分散性及界面结合提高;(MWNT-SiO2)/RTV复合材料压力敏感性增强,当外界压力为150N时,含5％二氧化硅的复合材料相对电阻是M...     

Preparation and properties of cast aluminium alloy-granite particle composites

With a view to develop light weight, low cost and abrasion resistant material cast aluminium alloy composites dispersed with granite particles were prepared and their properties were evaluated. Natural mineral granite was crushed and treated prior to its incorporation in the aluminium alloy. Liquid metallurgy techniques was used to prepare composites involving the following steps: melting of aluminium alloy in graphite crucible, stirring of the melt, addition of granite particles and reactive metal in the melt and pouring the composite melt into permanent moulds. Physical, mechanical, tribological and metallographic properties of composites were studied. It was observed that there was reasonably uniform dispersion of granite particles in the matrix. Hardness and tribological (abrasive wear) properties of the base alloy improved considerably due to addition of the granite particles into it. This clearly indicates that these cast aluminium alloy based composites can be used as wear resistant materials.     

纳米硅/炭复合材料的制备及其电化学性能

将纳米Si粉以一定配比分散在石油重油中,在高压反应釜中经过460℃自升压热解反应,再经900℃炭化制备一种锂离子二次电池负极用纳米硅/炭（Si/C）复合材料。考察了纳米Si粉添加量对产物收率、微观结构及电化学性能的影响。结果表明：纳米Si粉的加入有助于提高固体产物的收率;在纳米Si/C复合材料中纳米Si粉均匀地镶嵌于炭基体中;纳米Si粉的晶型在热解反应前后没有发生变化。当纳米Si粉与石油重油质量比为5∶100时制备的纳米Si/C复合电极材料具有498mAh/g的首次可逆比容量和90%的充放电效率。     

拟薄水铝石改性环氧树脂复合材料的制备与性能

采用水热合成法制备拟薄水铝石(AlOOH)纳米棒,以3-氨基丙基三乙氧基硅烷(APTES)为表面改性剂,制得mAlOOH,以环氧树脂(Epoxy,EP)为基体,制备AlOOH/EP和mAlOOH/EP复合材料。研究AlOOH和mAlOOH的填充量对AlOOH/EP及mAlOOH/EP复合材料性能的影响。结果表明,mAlOOH明显提高了mAlOOH/EP复合材料的力学性能。mAlOOH的填充量为4wt%时,mAlOOH/EP复合材料的冲击强度和弯曲强度分别比聚合物基体分别提高了259%和44%;填充量不超过5wt%时,mAlOOH/EP的介电常数与介电损耗均略低于纯环氧树脂。当添加量为3wt%时,mAlOOH/EP具有最低的介电常数和介电损耗及最高的玻璃化转变温度(123℃)。      

Preparation and properties of hollow glass microsphere-filled epoxy-matrix composites

Hollow glass microsphere (HGM)–filled epoxy composites, with filler content ranging from 0 to 51.3 vol.%, were prepared in order to modify the dielectric properties of the epoxy. The results showed that the dielectric constant (D_k) and dielectric loss (D_f) of the composites decreased simultaneously with increasing HGM content, which was critical for the provision of superior high-frequency device performance. Other properties of the composite, such as the coefficient of thermal expansion (CTE) and the glass transition temperature (T_g), were also improved. The improvement in these properties was related to strong interaction between the HGM and epoxy, which was indicated by the formation of an interphase between the HGM and epoxy-matrix. It was unsatisfactory in this study that the thermal conductivity of the composites also decreased with HGM content. In order to obtain relatively high thermal conductivity and a low dielectric constant simultaneously, this paper suggests further adding other filler.     

生物质炭/ZnO复合材料的制备及其吸附-光催化性能

以纳米晶纤维素（NCC）为形貌诱导模板,醋酸锌（Zn（CH₃COO）₂·2H₂O）为Zn源,采用原位聚合法制备NCC/ZnO纳米杂化物,再经550℃高温碳化,得到生物质炭/ZnO复合材料。采用TEM、XRD、BET、UV-Vis测试研究生物质炭与ZnO固体质量比（0.03:1、0.17:1、0.67:1）对生物质炭/ZnO复合材料形貌、晶体结构、孔结构及光吸收性能的影响。并进一步以亚甲基蓝（MB）为模型污染物,研究生物质炭/ZnO复合材料的吸附-光催化性能,阐明其吸附-光催化机制。结果表明,经550℃高温碳化后,NCC转化为具有石墨微晶结构的生物质炭,其骨架结构得以保留,纳米ZnO均匀负载在生物质炭表面,形成生物质炭/ZnO复合材料。与纯纳米ZnO相比,生物质炭/ZnO复合材料比表面积显著提高,具备优异的吸附性能,同时,NCC转化得到的生物质炭有效提高了ZnO的光生电子-空穴对的分离率。生物质炭/ZnO复合材料通过吸附-光催化协同效应去除水体中的MB,去除率显著增加。当生物质炭与ZnO的固体质量比为0.17:1时,生物质炭/ZnO复合材料的平均孔径为188.99 nm,比表面积为33.51 m2/g,在室温条件下,避光吸附30 min后,再使用500 W紫外灯照射20 min,即对MB降解率达到99.8%。      

超声作用下树脂基磁致伸缩复合材料的制备及其性能

树脂基磁致伸缩复合材料是由Terfenol-D颗粒分散在树脂基体内形成的一类复合材料,颗粒的分散均匀性以及颗粒与基体界面的粘结紧密性是影响其性能的两个重要因素.由于颗粒与基体润湿性差,机械搅拌制备的磁致伸缩复合材料,普遍存在分散不均,孔隙率高等缺点.高强度超声在液态树脂中传播时,会产生空化、声流等非线性声学效应,对促进颗粒分散和改善固液界面具有一定的作用.以环氧树脂为基体,分别采用机械搅拌法和高能超声法制备了Terfenol-D颗粒体积含量为50%的树脂基磁致伸缩复合材料.对两种材料进行了SEM分析及力学和磁致伸缩性能测试.实验结果表明,较之机械搅拌法,超声分散法制得的磁致伸缩复合材料具有颗粒分散均匀,孔隙率低,颗粒与基体的界面结合性好,弹性模量高,磁致伸缩应变大等优点.     

超高分子量聚乙烯/石墨烯纳米复合材料的制备及其热性能的研究

为了提高超高分子量聚乙烯的热性能,本文通过溶液共混的方法利用氧化石墨烯改性不同分子量的超高分子量聚乙烯,然后利用红外测试(FTIR)、X射线衍射测试(XRD)、扫描电镜测试(SEM)、差热扫描量热分析仪(DSC)和热失重分析(TG)的方法对超高分子量聚乙烯/石墨烯纳米复合材料的结构、表面形态和性能进行了研究.通过分析测试表明氧化石墨烯在超高分子量聚乙烯/石墨烯纳米复合材料中的分散性良好,氧化石墨烯的添加量为0.3%时,石墨烯/超高分子量聚乙烯的复合材料的热稳定性等性能最好,与原材料相比提高了3℃.     

石墨/陶瓷复合导电材料的制备及性能

为了研究片状石墨的掺杂量和取向排列对石墨/陶瓷复合材料结构和性能的影响,以长石、透辉石、石英等作为陶瓷基体并掺杂石墨,经湿混、干燥、干压成型、快速烧结等工艺制备了石墨/陶瓷复合导电材料。用精密伏安表精确测定了材料垂直和平行于成型压力方向的电阻,用XRD、SEM分析了试样的物相组成和断面形貌。实验结果表明：在烧结过程中石墨与陶瓷基体不发生化学反应,未发现有新相生成;片状石墨在复合材料中具有定向排列的特征,即片状石墨的c轴平行于成型压力方向;石墨/陶瓷复合导电材料的电阻率具有明显的各向异性;随着石墨掺量的增加,复合导电材料的电阻率随石墨掺量的增加而急剧减小;但是,当石墨掺量超过15 wt%时,复合材料电阻率的变化趋于平缓。