硫酸亚铁催化马来酸酐改性汉麻秆芯粉的研究

由于植物纤维具有较强的表面化学极性和亲水性,而高分子树脂基体的化学极性小,所以两者之间的界面结合较差,复合材料的力学性能低。这些问题极大地阻碍了植物纤维增强复合材料的制备与应用。因此,为了提高界面相容性,要对植物纤维进行表面改性。利用马来酸酐对汉麻秆芯粉进行改性,并对改性后的汉麻秆芯粉进行了转化率、红外光谱、亲疏水性、扫描电镜测试。分析结果表明,1%硫酸亚铁溶液,30%马来酸酐溶液改性的汉麻秆芯粉改性效果最好。马来酸酐改性后的汉麻秆芯粉体表面粗糙且相互缠结,亲水性明显下降。     

煤矸石粉的改性及其对SBS力学性能的影响

为进一步改善超细煤矸石粉的表面活性,利用具有偶联和润滑作用的聚合助剂Wy1502对超细煤矸石粉进行表面改性,采用混炼工艺制备了SBS(苯乙烯-丁二烯-苯乙烯嵌段共聚物)/超细煤矸石粉复合材料。通过傅立叶红外光谱(FTIR)、扫描电镜(SEM)、热重分析(TGA)、力学性能和熔体流动性测试等手段对粉体结构和复合体系的性能进行了分析。结果表明,助剂Wy1502与超细煤矸石粉间能形成化学结合,并有效阻止粉体颗粒的团聚;改性后超细粉体与SBS界面相容性改善,使材料力学性能明显提高,加工性降低,热稳定性提高。     

界面改性对秸秆粉/PE-HD复合材料性能和热降解特性的影响

分别采用硅烷偶联剂(A171)处理、相容剂(MAPE)处理以及A171/MAPE处理的界面改性法对秸秆粉/高密度聚乙烯(PE-HD)复合材料界面进行改性。结果显示:3种处理方法均改善了秸秆粉与基体间的界面黏结,增强了力学性能和防水性能;界面改性后,复合材料的熔融流变行为因秸秆粉与PE-HD的交联而变差;秸秆粉的初始热分解温度向高温移动,热稳定性增加。A171/MAPE复配处理对复合材料界面改性效果最好,对材料性能的影响最显著。     

无机粉体填充改性热塑性塑料机理探讨

介绍了无机粉体填充改性机理及影响界面特性的因素如界面应力、高分子树脂的极性、无机粉体与高分子树脂间的相容性、无机粉体粒径等。同时综述了复合材料的微观相界面设计与调控技术。通过对无机粉体的表面性能进行优化与改进,可设计并制造出性能更加优异的复合材料。     

碳纳米材料接枝碳纤维的复合材料界面增效研究进展

界面作为复合材料的重要组成部分,起着传递载荷的作用,影响复合材料的整体性能。碳纤维表面属于石墨乱层结构,微晶有序取向,惰性大,不易与树脂基体结合。对碳纤维进行适当的表面改性,增加纤维的比表面积、粗糙度和引入活性官能团,都能改善表面润湿情况,实现机械结合和化学结合,提高复合材料的界面性能。碳纳米材料接枝到碳纤维表面,是提高界面性能的有效方法之一。因此,对碳纳米管、氧化石墨烯接枝碳纤维的制备方法、界面增效设计以及界面增强机制的国内外研究现状进行综述和分析,在此基础上,展望了碳纳米材料接枝碳纤维表面和界面性能评价方法的研究趋势和前景。     

偶联改性玄武岩纤维增强沥青胶浆性能及机理研究

针对偶联改性玄武岩纤维增强沥青胶浆现有研究现状和不足,采用硅烷偶联剂对玄武岩纤维进行表面改性,制备了不同粉胶比和不同纤维掺量的偶联改性玄武岩纤维增强沥青胶浆,通过低温延度、弹性恢复、锥入度及软化点试验,研究了沥青胶浆低、中、高温性能,并对偶联改性玄武岩纤维增强沥青胶浆机理进行分析。研究表明,偶联改性玄武岩纤维与沥青胶浆润湿性好、黏附性强,表面沥青胶浆膜厚度大,纤维力学特性发挥显著,粉胶比在0.8~1.0、纤维掺量在0.4%~0.6%之间时,沥青胶浆抗拉强度、抗剪强度、弹性恢复率及软化点明显提高,沥青胶浆低温抗裂、高温抗剪切、疲劳性能及自愈能力得到较大改善,研究成果对矿物纤维复合材料在道路工程中的推广与应用具有一定的实际意义。     

丁苯橡胶/膨胀珍珠岩复合材料的制备

用硅烷偶联剂Si-69对膨胀珍珠岩粉进行表面改性,并用模压法制备了丁苯橡胶/膨胀珍珠岩复合材料.考察了Si-69和改性膨胀珍珠岩粉的用量对复合材料性能的影响,通过热重测试(TGA)分析了复合材料的热性能,采用电子扫描显微镜(SEM)观察了复合材料的撕裂断面形貌.实验结果表明:改性膨胀珍珠岩粉适量填充丁苯橡胶能明显提高复合材料的力学性能和热性能.膨胀珍珠岩粉经适量Si-69改性后,有利于提高其与丁苯橡胶的两相界面相容性.     

ZnO纳米棒提高碳纤维增强树脂基复合材料界面性能

碳纤维增强树脂基复合材料因其高的比强度和比模量,在航空航天等领域被广泛地应用。目前,碳纤维与树脂的界面性能是制约复合材料性能的关键因素。通过简单的水热法,在碳纤维表面合成了ZnO纳米棒阵列。在不同的生长时间下,制备了具有不同长度的ZnO纳米棒。ZnO纳米棒改性之后树脂对碳纤维的浸润性能明显提高。同时,复合材料的界面剪切强度得到明显提升,最大增幅达到了28.4%。通过扫描电子显微镜观测了单丝拔出后碳纤维的表面形貌,结果表明:改性碳纤维单丝拔出后表面粗糙而且残留了断裂的树脂基体,进一步证明碳纤维表面生长ZnO纳米棒之后界面强度得到改善。     

不同形态矿物复合增强LDPE的研究

利用硅灰石、白云母和珍珠岩等3种具有特殊晶体结构和形态的矿物粉体,进行表面改性处理,与低密度聚乙烯(LDPE)复合加工制备复合材料。结果表明,甲基丙烯酰氧基三甲氧基硅烷对3种矿物粉体的改性效果较好;在总用量为30%,硅灰石∶白云母∶珍珠岩为1∶1∶1时,复合材料的强度、耐磨性、流动性都得到增强,复合材料性能优于纯LDPE。     

聚丙烯/纳米二氧化硅复合材料性能的研究

通过熔融共混的方法制备了聚丙烯/纳米二氧化硅(PP/Nano-SiO2)复合材料,利用微机控制电子万能试验机、液晶式摆锤冲击试验机、差示扫描量热仪、毛细管流变仪和扫描电子显微镜研究Nano-SiO2粉体表面改性前后和添加适量增容剂对PP/Nano-SiO2复合材料性能的影响。结果表明:Nano-SiO2粉体对基体PP有异相成核作用,使PP/Nano-SiO2复合材料结晶放热峰明显向高温方向移动;在经偶联剂(KH560)表面改性并添加适量增容剂(PP-g-MAH)协同作用下,Nano-SiO2粉体与PP两相界面的相互作用增强,PP/Nano-SiO2复合材料的相容性提高;冲击强度提高76%,剪切应力随着剪切速率的增大而提高,表观黏度随剪切速率和温度的提高而逐渐降低,改善了复合材料的加工性能。     

Preparation and properties of composite mineral powders

Mineral powders such as ground calcium carbonate (GCC) and wollastonite are widely used as fillers in plastics, rubber, paper, paints and other fields. The interface compatibility between the polymer matrix and the mineral particles is relatively weak, both because of the smooth cleavage surface and the sharp particle edges formed during pulverizing. It is beneficial therefore to modify the surface properties of mineral powders before they are used in a polymer composite. In this paper, we report the successful preparation of composite mineral particles, coated by nanoparticles of calcium carbonate of 20-100 nm particle size, by chemical reaction using the Ca(OH)₂-H₂O-CO₂ system. The degree of nanoparticle coverage can reach 100% if the operating parameters are effectively controlled, and the specific surface area can be increased to three times the value before modification. Mechanical testing of polypropylene containing composite wollastonite powder as a filler shows an increase in the impact strength of 65% compared to similar samples prepared using conventional filler powder.     

绢云母粉对RTV硅橡胶性能的影响

以羟基封端聚二甲基硅氧烷为基胶，绢云母粉为填料制成了RTV硅橡胶，研究了绢云母粉制造工艺，用量，粒径对RTV硅橡胶力学性能和工艺性能的影响。结果表明，一定粒径和适当添加量的湿法绢云母粉可以增强RTV硅橡胶的拉伸强度，断裂伸长率等力学性能，同时工艺性能也较好。当绢云母粉粒径在300目左右，用量为10份时，RTV硅橡胶的综合性能比较好。     

合成绝缘子组装用室温硫化硅橡胶

研究了一种用于合成绝缘子组装的单组分室温硫化硅橡胶（RTV-1）。重点考查107胶、增塑剂、填料及偶联剂对RTV-1的流平性及其粘接性能的影响。结果发现,该RTV-1粘接绝缘子材料效果优异,自流平性好,可用于合成绝缘子粘接组装。     

Nonreinforcing filler–elastomer systems. II. Silane–treated ammonium perchlorate in polybutadiene

The adhesion between ammonium perchlorate filler and the polybutadiene rubber matrix was investigated. The aggregate composite was modified by surface pretreatment of the filler with various organofunctional silanes. For comparison, the adhesion of glass beads and glass powder, each coated with a fluorocarbon release agent, and carbon black were used as fillers in the cured polybutadiene matrix. Common testing methods used included the determination of Poisson's ratio, photographic analysis, and absorption of water. A new type of stress–strain analysis was introduced. Results closely agreed with established composite theory. The presence of methacryloxy- and amino-functional silanes improved adhesion to the resin system. Epoxy- and vinyl functional silanes proved to be detrimental at the filler–rubber interface. A major function of the coupling agents appears to be to eliminate the weak boundary layer of surface moisture on the filler particles.     

Effect of the particle size of Al2O3 on the properties of filled heat‐conductive silicone rubber

An elastomeric thermal pad with a thermal conductivity of 1.45 W/m K, needed for the heat dissipation of microelectronics, was obtained with hybrid alumina of different particle sizes as a filler and silicone rubber (vinyl‐end‐blocked polymethylsiloxane) as the matrix. The effects of the amount, particle size, and mixing mass ratio of the filler particles on the thermal conductivity and mechanical properties of silicone rubber were investigated. The results indicated that the thermal conductivity of the rubber filled with larger particles was superior to that of the rubber filled with the smaller grain size, and the rubber incorporated with a mixture of hybrid particles at a preferable mass ratio exhibited higher thermal conductivity than the rubber for which a filler with only a single particle size was used. In addition, the surface treatment of the hybrid filler with 3‐methacryloyloxypropyltrimethoxysilane could increase the thermal conductivity of the composite rubber. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1312–1318, 2007     

石墨及其表面改性对硅橡胶导热性能的影响

用双辊混炼机将导热填料分散到聚甲基乙烯基硅氧烷中,再配以增强剂、硫化剂等,经模压硫化制得导热硅橡胶。研究了导热填料种类、石墨的表面改性和用量以及石墨与炭黑的复配对硅橡胶导热性和力学性能的影响。结果表明,在用量相同的情况下,导热填料的导热系数越高,其填充硅橡胶的导热性越好,且硅橡胶的导热系数随导热填料用量的增加而增大。石墨的表面改性改善了石墨与硅橡胶的界面相容性,使硅橡胶的力学性能和导热性都得到提高。不同粒径及颗粒形态的炭黑与石墨复合可改善硅橡胶的导热性和力学性能,导热硅橡胶的拉伸强度和扯断伸长率随复合填料中炭黑用量的增加而提高,当石墨与炭黑质量比为25/5时,硅橡胶的导热系数最高,综合性能较好。     

Thermally conductive silicone rubber reinforced with boron nitride particle

Thermally conductive silicone rubber used as elastomeric thermal pad is successfully developed with boron nitride powder as conductive filler. The effects of content and particle size of filler on the thermal conductivity and mechanical property of silicone rubber are investigated. The results indicate that the use of hybrid boron nitride with three different particle sizes at a preferable weight ratio gives silicone rubber better thermal conductivity compared with each boron nitride with single particle size at the same total filler content. Furthermore, scanning electron microscopy, differential scanning calorimeter, thermogravimetric, etc., are used to characterize the morphology, curing behavior, thermal stability, and coefficient of thermal expansion (CTE) of the silicone rubber composites. POLYM. COMPOS., 28:23–28, 2007. © 2007 Society of Plastics Engineers     

用于冲压发动机补燃室热防护的硅橡胶绝热层研究

通过分析影响冲压发动机补燃室热防护层性能的因素,研究了粉状填料和纤维填料对硅橡胶绝热层耐烧蚀性能的影响和填料的组合作用;研究了硅橡胶绝热层与发动机壳体的粘接性能,将几种偶联剂对绝热层与壳体粘接性能的影响进行了对比.结果表明,通过有机填料与无机填料以及纤维的共同作用,可以显著提高硅橡胶绝热层的耐烧蚀性能,降低其烧蚀率;WD-60偶联剂可显著提高硅橡胶与钢的粘接强度.初步探索出适合于冲压发动机补燃室热防护所用的硅橡胶绝热层配方.     

加成型导热电子灌封硅橡胶的研究

以α,ω-二乙烯基聚二甲基硅氧烷为基胶,配合石英粉、氧化铝、含氢硅油、Pt催化剂等,制成加成型导热电子灌封硅橡胶.研究了导热填料及其用量对加成型导热电子灌封硅橡胶性能的影响.结果表明,石英粉与氧化铝填料都可以提高液体硅橡胶的导热性能,但是随着填料的粒径增大,硅橡胶的机械性能逐渐下降;对比两种导热填料,石英粉体系液体硅橡...     

Effect of CeO2 on UV aging of composite insulators prepared by template-spraying method

When the silicone rubber composite insulator is exposed outdoors for a long time, it will be affected by high-temperature ultraviolet environments. In order to ensure the operation of silicone rubber composite insulators, a super-hydrophobic composite insulator with antiaging characteristics was prepared by mixing cerium dioxide (CeO₂) with silicone rubber and spraying CeO₂ on the surface of silicone rubber. This article studied the aging characteristics of the base and surface of silicone rubber composite insulator by CeO₂ in ultraviolet environment. The properties of silicone rubber composite insulators before and after aging were tested by mechanics, contact Angle, rolling Angle, bounce, and icing experiments. The aging mechanism of silicone rubber was analyzed by Fourier transform infrared spectroscopy and search engine marketing. This study prepared composite insulators with excellent mechanical, hydrophobic, and antiicing properties. The aging resistance of silicone rubber composite insulators is improved by adding CeO₂ into silicone rubber matrix and spraying CeO₂ on the surface, which also ensure the use of composite insulators in high-temperature ultraviolet environment.