聚丙烯/蒙脱石阻燃纳米复合材料的研究

阐述了纳米复合材料阻燃性研究的进展,介绍了其制备方法、微观结构的表征手段(XRD)及阻燃性测试技术(锥形量热仪,TGA,氧指数仪),讨论了其燃烧特性和阻燃机理.指出了这种阻燃方法目前存在的问题,展望了该阻燃材料开发应用前景.     

Effect of Vortex Restructuring on Heat Transfer in an “Inverted” Flame

The papers deals with formation of vortex structures during combustion of a fuel gas–air mixture injected vertically down through a hole in a flat plate. It has been established that the shape, position, and number of vortex cells are determined by the flow rate and composition of the fuel mixture. It is shown that as the flow rate increases from the minimum critical value for which a vortex structure arises, the number of vortex cells decreases from five or six to one. A further increase in the gas flow rate leads to transition to turbulence of the combustion product flow. The presence of a vortex structure increases the critical Reynolds number at which the flow becomes turbulent. Reverse transition to the structure with an increased number of vortex cells occurs with a delay in the gas flow rate (gas discharge hysteresis). Variation in flow rate is accompanied by bifurcation of the number of vortex cells.     

Latent catalyst effects in halogen‐free epoxy molding compounds for semiconductor encapsulation

Latent catalyst effects were investigated to improve the physical properties of halogen‐free epoxy molding compounds (EMCs) for semiconductor encapsulation. In this study, biphenyl‐type resins were used as the epoxy and hardener resin for halogen‐free EMCs to obtain high flame‐retardant properties and high filler contents. Latent catalyst effects were examined with two kinds of EMC compositions, halogen‐free EMCs and conventional EMC compositions. We used triphenylphosphine‐benzoquinone salt (TPP‐BQ) as a latent catalyst. Spiral flow and gel time were measured to investigate the change in moldability with the latent catalyst. We measured package fail, moisture absorption, and delamination for reliability evaluation and flexural strength, flexural modulus, and adhesion for mechanical properties to examine latent catalyst effects. An improvement in moldability, reliability, and the mechanical properties were observed in two types of halogen‐free EMCs with TPP‐BQ as a latent catalyst. These phenomena were seen in conventional EMCs, including o‐cresol novolac epoxy resin. The cure kinetics of these systems were investigated by differential scanning calorimetry with an isothermal approach to explain these phenomena. The results indicate that the improvement in moldability in halogen‐free EMCs with TPP‐BQ was due to the low conversion rate of this system, and the increase in mechanical properties was attributed to the high conversion of curing reaction. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 2287–2299, 2005     

等离子喷涂羟基磷灰石涂层

羟基磷灰石由于具有优良的生物性能，被广泛应用于生物材料领域，而等离子喷涂制备羟基磷灰石涂层是应用最为广泛的制备方法之一。在综合国内外献的基础上，本从羟基磷灰石的本征性能、喷涂工艺的影响、结合强度和梯度涂层等方面进行综述。     

羧基偏氯乙烯丁苯胶乳粒子的相态结构和应用性能

以过硫酸铵为引发剂，十二烷基硫酸钠为乳化剂，采用种子聚合工艺，合成了偏氯乙烯质量分数为２３％～４３％的羧基偏氯乙烯丁苯胶乳。通过电镜观察到所合成的胶乳粒子具有核－壳结构。通过测定胶闰子表面层的羧基数量，研究了羧基的分布，结果表明，羧酸种类对羧基在胶乳粒子中及在聚合体系中的分布有重要影响，该胶乳作为地毯背衬粘合剂，具有粘合力高，极限氧指数高的特点，是一种较好的阻燃性粘合剂。     

Zinc hydroxystannate and zinc stannate as flame‐retardant agents for flexible poly(vinyl chloride)

The flame‐retardant and smoke‐suppressant properties of inorganic tin compounds such as zinc hydroxystannate (ZHS) and zinc stannate (ZS) were investigated in a comparison with alumina trihydrate, magnesium hydroxide, and Sb₂O₃ through the limiting oxygen index test and smoke density test. The flame‐retardant mechanisms were studied through the char yield test, SEM, quantitative analysis, thermogravimetry and differential thermal analysis. The thermal degradation in air of flexible PVC treated with the above compounds was studied by thermal analysis from ambient temperature to 800°C. The results showed that tin compounds such as ZHS and ZS could be used as a highly effective flame retardant for flexible PVC, and it appears that the tin compound may exert its action in both the condensed and vapor phases, but mainly in condensed phases as a Lewis acid. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1469–1475, 2005     

过磷酸钙喷涂法生产硫基复合肥工艺研究

简述了过磷酸钙喷涂法生产硫基复合肥的反应原理及工艺方案、实施方案的确定。给出了该工艺较传统工艺的优势及特点。     

防火涂料热降解的测试研究技术

介绍了防火涂料热降解的测试研究技术,并举例说明了这些技术在研究防火涂料热降解过程及机理中的作用,评述了各种测试研究技术的特点,说明采用多种测试技术联用是分析防火涂料热降解的方向。     

防粘釜剂在PVC糊树脂生产中的应用

探索了在PVC糊树脂生产中使用的防粘釜剂技术,以缩短聚合辅助时间。在试验期间,对目前市场上的防粘釜剂进行筛选,并对防粘釜剂喷涂设备、喷涂条件、喷涂方法、喷涂效果以及防粘釜剂的用量等一系列问题进行了研究。结果表明,防粘釜剂的使用,不仅缩短了聚合辅助时间,而且对产品质量没有任何影响。     

尿素熔融喷浆造粒工艺在复混肥生产中的应用

介绍了在团粒法工艺的基础上,将尿素熔融成尿液进行喷浆造粒生产复混 肥过程中存在的问题,分析产生的原因并提出改进措施,对改造效果进行了总结。