Formation of composites fabricated by exothermic dispersion reaction in A1-TiO2-B2O3 system

The formation of aluminum matrix composites fabricated by exothermic dispersion reaction in A1-TiO2-B2O3 system was investigated. The thermal analysis results show that the reactions are spontaneous and exothermic. The Gibbs free energy of α-Al2O3 is the lowest among all the combustion products, followed by TiB2 and Al3Ti. It is noted that when the B2O3/TiO2 mole ratio is below 1, the reaction products are composed of particle-like α-Al2O3, TiB2 and rod-like Al3Ti. The α-Al2O3 crystallites, resulting from the reaction between A1 and TiO2 or B2O3, are segregated at the grain boundaries due to a lower wettability with the matrix. SEM micrographs show that rod-like Al3Ti phase distributes uniformly in the matrix. When the BEO3/TiO2 mole ratio is around 1, the Al3Ti phase almost disappears in the composites, and the distribution of α-Al2O3 particulates is improved evidently.     

兼具弹性和拉伸强度的热塑性聚氨酯纳米复合材料

通常加入传统的、商业可得到的纳米填充物会使弹性纳米复合物体系弹性变差，并具有更高的硬度。澳大利亚Queensland大学利用纳米粒子开发了一种新型软质热塑性聚氨酯（TPU）弹性体复合物，据称该复合物具有优异的拉伸强度和抗撕裂性能。     

Fe3O4有机复合物的磁流变性质研究

制备了一种新型的Ｆｅ３Ｏ４有机复合物磁流变体，研究了在外磁场作用下此磁流变体中微粒的分布及粘度变化。结果表明，此磁流变体具有较强的磁流变活性。     

一种新型功能材料——Ag／Si纳米复合物薄膜的结构及光学性质

采用复合靶及离子微波控制共溅射方法制备了银（Ａｇ）硅（Ｓｉ）复合物薄膜。透射电观察表明，银晶体小颗粒（１－３ｎｍ）镶嵌于非晶基体中。近紫外、可见光及近红外吸收光谱分析表明，当银含量低于５０ａｔ％时，薄膜显示典型非晶半导体光谱特征；当银含量高于５０ａｔ％时，在近紫外及可见波段显示两个吸收峰，讨论了其可能的吸收机制     

美国研制新型水果保护膜

美国农业研究局的科学家用新型配方的虫胶和蔗糖酯，研制出一种新型水果保护膜。蔗糖酯是一种将蔗糖与酯及酸混合为一体的复合物。这种生物控制保护膜可以通过促使有利细菌在水果表面自然生长保持水果质量。这项研究是使水果种植者减少依赖化学剂来延缓水果收获后腐烂的一部分。研究人员已经发现，常用于保存收获后水果的每公斤1千美元的烯菌灵和用于保存佛罗里达葡萄柚的涕必灵这两种化学剂会杀死有益的细菌和酵母菌群。     

PP/弹性体共混合物与PET短纤维的复合物

将聚对苯二甲酸乙二醇酯(PET)纤雏加入等规聚丙烯(iPP)和乙烯-辛烯共聚物的共混物后。三元复合物的物理和力学性能发生了变化，为了估算基质组分和纤维含量时复合物性能的影响，应用了建立在多赫勒均匀网基础上的一种试验方法。研究结果表明，PET纤雏对PP／乙烯-辛烯共聚物的共混物有补强作用，当共混物中共聚物高比例时这种作用更明显。     

聚吡咯导电材料合成方法的进展

本文对聚吡咯及聚吡咯导电复合物的合成方法进行了综述。     

热致液晶性纤维素衍生物及其热塑性塑料复合物熔体流变行为的研究

用毛细管流变仪研究了乙基纤维素（ＥＣ）及其高密度聚乙烯（ＨＤＰＥ）复合物，纤维素芳族酯（ＣＡＥ）及其聚碳酸酯（ＰＣ）复合物的剪切流变特性和机理。结果表明，ＥＣ对ＨＤＰＥ／ＥＣ复合物的粘度影响不大，而少量（５％）ＣＡＥ的加入使ＰＣ／ＣＡＥ复合物粘度大大下降，且复合物流变曲线呈现新的特征。     

In—situ Composite Based on Poly （ethylene terephthalate）,Polyamide and Polyethylene with Microfibres Formed through Extrusion and Hot Stretching

In-situ composites based on dispersed poly (ethylene terephthalate) (PET) or polyamide (PA),and continuous Polyethylene (PE) were prepared through a single screw extruder of Haake rheometer system with a rod-die relatively small in diameter.The extrudate was drawn at a drawing ratio of 3.1,and then quickly cooled in cold water.The specimens were obtained by injection molding at processing temperatures less than 190℃，far below the melting temperature of PET (265℃) and PA (230℃),which can maintain the solid state of PET and PA microfiber phase in the composites.Morphological observation with scanning electron microscopy (SEM) indicated that PET and PA can more or less form in-situ microfibers at compositions studied (0-20 wt pct PET or PA),and especially,PET and PA were almost deformed into fibers at the concentration of 15wt pct.Eensile strength and especially.PET and PA were almost deformed into fibers at the concentration of 15wt pct.Tensile strength and modulus of the blends reinforced by PET or PA microfibers showed to be increased from the tensile test results.The most noticeable improvement of the tensile properties occurred at 15wt pct of PET in PET/PE system,corresponding to the highest microfiber content,where the tensile strength reached 32.5 MPa,whereas only 19.5 MPa for the pure PE.