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...     

导热硅橡胶的研究进展

概述了导热硅橡胶的导热模型与导热机理;介绍了国内外导热硅橡胶的研制与开发情况,提出了提高硅橡胶导热性能的三种途径;阐述了导热硅橡胶的应用及发展方向。     

导热硅橡胶研究进展

概述了导热硅橡胶的导热机理和模型,介绍了改善硅橡胶导热性能的主要途径,阐述了导热硅橡胶的应用情况,并对其今后研究方向进行了展望。     

导热硅橡胶的研究进展

综述了导热橡胶的典型理论模型和导热机理,并对国内外导热硅橡胶的研究现状做了详细介绍。硅橡胶的导热性主要取决于硅橡胶基体、填料、以及加工工艺三个方面的因素。填料的导热性、添加量及其在基体中的分布形式对硅橡胶的导热性能起着关键作用。     

环氧灌封材料的研究进展

介绍了电子产品环氧灌封材料的两种灌封工艺；常态灌封和真空灌封；针对环氧树脂本身脆性大的缺点，详述了环氧灌封材料的增韧方法，主要包括端羧基聚丁二烯-丙烯腈(CTBN)增韧、复合弹性体微粒增韧、液晶环氧增韧、氰酸酯树脂增韧和纳米粒子增韧，同时对其增韧效果进行了评价；最后列举了三种典型环氧灌封材料的应用配方和它们的性能指标。     

导热硅橡胶的研究进展

概述了导热硅橡胶的导热模型与导热机理;介绍了国内外导热硅橡胶的研制与开发情况,提出了提高硅橡胶导热性能的三种途径;阐述了导热硅橡胶的应用及发展方向.     

导热硅橡胶的研究进展

综述了填充型导热橡胶的导热机理和各类导热填料的导热特性,介绍了提高导热硅橡胶导热性的途径。     

缩合型有机硅电子灌封材料之固化体系研究

以二丁基二醋酸锡（D-70）为催化剂,分别以二甲基二乙氧基硅烷、三乙氧基硅烷、正硅酸乙酯、硅酸乙酯-40（Si40）及其混合物作为固化剂,比较了不同固化剂对硅凝胶表干时间和硬度的影响。结果表明,室温下采用三乙氧基硅烷固化速度很慢,而采用正硅酸乙酯和正硅酸乙酯低聚物Si40时固化速度相近,凝胶硬度也相差不大。对混合固化剂来说,二甲基二乙氧基硅烷与正硅酸乙酯配伍较好（质量混合比例在1左右）。该催化固化体系可用于快速电子灌封凝胶的制备。     

导热绝缘硅橡胶的研究进展

随着工业的发展,人们对橡胶在电子器件的封装及散热、电器绝缘材料的导热以及航空航天等特殊场合的热控制方面提出了更严苛的性能要求,因此迫切需要开发出一种导热、绝缘等综合性能优良的橡胶材料.综述了近年来各类导热绝缘无机填料填充硅橡胶的研究进展,并指出目前急需解决的重要问题及未来应加强的几个方面的基础研究.     

导热室温硫化硅橡胶的研究进展

介绍了导热室温硫化硅橡胶的导热机理及导热模型,分析了室温硫化硅橡胶的导热性能及综合性能,并概述了国内外导热室温硫化硅橡胶的研究现状。指出通过填充不同粒径分布的填料或对填料进行适当的表面处理,可以制备高导热室温硫化硅橡胶。     

填充型导热橡胶研究进展

介绍了导热橡胶的研究现状,综述了导热绝缘与导热非绝缘橡胶导热性能及导热模型的研究进展,重点讨论了金属氧化物、碳化物、氮化物、金属粉、炭黑及各类碳材料填充导热橡胶的研究进展。     

导热填料对室温硫化硅橡胶性能的影响

分析比较了氮化硅、氧化锌、勃姆石、氮化铝、碳化硅和石英粉等6种填料对室温硫化硅橡胶性能的影响,优选出氮化硅作为导热填料。比较了不同粒径的氮化硅性能,制备了综合性能较好的导热室温硫化硅橡胶。     

镀银铜粉填充型导电硅橡胶的研究

研究了镀银铜粉填充型硅橡胶的导电性能。结果表明 :采用乙烯基三过氧叔丁基硅烷偶联剂对镀银铜粉进行表面处理 ,可改善胶料的混炼工艺性 ,提高镀银铜粉的添加量 ;同时也可提高硫化胶中镀银铜粉与硅橡胶的结合力 ,使表层镀银铜粉颗粒不易脱离 ,相应地提高了硅橡胶的导电稳定性 ;所得镀银铜粉填充型导电橡胶的体积电阻率小于 0 0 1Ω·m。     

自然老化对导电硅橡胶电阻特性的影响

分析了异电硅橡胶的电阻性特自然老化条件下的变化规律,发现自然老化对导电硅橡胶电阻行性的影响与导电粒子的质量分数有关,并确定了最佳的导电粒子质量分数。     

Novel heat‐conductive composite silicone rubber

The silicone rubber with good thermal conductivity and electrical insulation was obtained by taking vinyl endblocked polymethylsiloxane as basic gum and thermally conductive, but electrically insulating hybrid Al₂O₃ powder as fillers. The effects of the amount of Al₂O₃ on the thermal conductivity, coefficient of thermal expansion (CTE), heat stability, and mechanical properties of the silicone rubber were investigated, and it was found that the thermal conductivity and heat stability increased, but the CTE decreased with increasing Al₂O₃ fillers content. The silicone rubber filled with hybrid Al₂O₃ fillers exhibited higher thermal conductivity compared with that filled with single particle size. Furthermore, a new type of thermally conductive silicone rubber composites, possessing thermal conductivity of 0.92 W/mK, good electrical insulation, and mechanical properties, was developed using electrical glass cloth as reinforcement. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2478–2483, 2007     

The correlativity of positive temperature coefficient effects in conductive silicone rubber

A thorough study on the positive temperature coefficient (PTC) effects of conductive silicone rubber was made. Various conductive silicone rubbers with apparent differences in PTC anomalies (defined as the ratio of peak resistivity to room temperature resistivity) were chosen. The correlation between the size of the PTC anomaly and both the thermal expansion coefficient of conductive silicone rubber and the interaction between silicone rubber and carbon black (CB) were found. The effects of cross‐linking on the temperature effect of resistivity of conductive silicone rubber were also studied. The results testify the important role of the interaction between silicone rubber and CBs in the temperature effect of resistivity of conductive silicone rubber. Copyright © 2005 Society of Chemical Industry     

自然老化对导电硅橡胶线性特性的影响

分别对未活加白炭黑和业加白炭黑增强的线性导电硅胶进行了５个月和１２个月的自然老化试验。结果表明,２种线笥导电硅橡胶的线笥特性是随自然老人时间的延长,其线性提高。     

Improving ablation properties of liquid silicone rubber composites by in situ construction of rich-porous char layer

In this article, ammonium polyphosphate (APP) and ammonium pentaborate (APB) were introduced to liquid silicone rubber with an aim of building rich-porous char structure in situ, thereby improving thermal insulation properties. Thermogravimetric analyses indicated that the incorporation of APP greatly increased the char residue of the composites. Oxy-acetylene torch tests showed that the addition of either APP or APB powders effectively enhanced the ablation resistance of the composites, whereas Shore A hardness tests revealed that the APP-containing composites exhibited a higher hardness than APB-filled counterparts. The linear ablation rates of composites with 40 phr APP or APB were reduced by 34.16% and 36.19%, respectively, when compared with the control sample. The maximum back-face temperatures of composites with 40 phr APP or APB was reduced to as low as 73°C. The APP-containing composites exhibited superior ablation resistance, considering both the linear ablation rate and the mechanical properties of char layer. In addition to SiO₂, SiC, and C, B₂O₃ was produced in the APB composites, as characterized by XRD and Raman analysis. Combined with SEM, it was proven that the formation of a firm, continuous, rich-porous and thermal insulation char layer was advantageous to improve the ablation and insulation properties.