塑料型材成型模拟技术

为了满足塑料异型材挤出的需要，根据熔料的流动状态，选择了最佳的口模结构。同时，介绍了计算机模拟技术在塑料异型材挤出中的应用。     

气体进入挤出机中熔体时气熔界面形态的分析

气体经单个喷嘴进入挤出机中熔体时所形成的气熔界面其形态有环状、团环状和团状三种，最常见的是团状。界面形态变化的过程分为球形膨胀、尾部颈缩和尾部收缩三个阶段。界面形态与进气压力、进气量、进气位置、流场情况有关，气泡的直径、长度和体积随进气压力的提高而增大，随螺杆转速的升高而减小。气泡脱离喷嘴的时间承受随进气压力和螺杆转速的升高而减小。实验分析表明，界面形态的变化直接影响发泡制品的质量。     

The influences of fiber feature and polymer melt index on mechanical properties of sugarcane fiber/polymer composites

The fiber characteristics (i.e., the fiber type, morphology, and dimension) and polymer melt flow index (MFI) significantly affected mechanical properties of sugarcane fiber/HDPE composites. The length and diameter of sugarcane fibers followed a lognormal distribution before and after compounding. The long fibers had a significant reduction in the dimension and aspect ratio during compounding. However, the short fibers had close values in these two properties before and after compounding. For the resultant sugarcane fiber/polymer composites, the HDPE resins with a low MFI value presented high tensile and impact strengths. Because of high sugar content, the pure rind fiber had a poor performance as filler in the HDPE resins with respect to the raw bagasse fiber and alkali‐extracted bagasse fiber. On the other hand, the aspect ratio was proportional to the mechanical performance of the fibers in the HDPE resins. As a result, the fibers with a large aspect ratio and low sucrose content improved the strength properties of the resultant composites. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5607–5619, 2006     

热熔压敏胶粘剂的市场和技术动向

综述热熔压敏胶粘剂在美国、欧洲、日本和中国的市场动向 ,和热熔压敏胶 (热塑弹性体 ,丙烯酸系、UV/EB固化系 )的发展     

Effect of comonomers on melt processability of polyacrylonitrile

This work is concerned with the feasibility of achieving melt‐processable polyacrylonitrile copolymer systems as precursors for the manufacture of carbon fibers. Identification of suitable comonomers and achieving the optimum content of the comonomer were some of the main objectives of this investigation. It was seen that methyl acrylate (MA) was found to be suitable for enabling the melt processing of polyacrylonitrile (PAN), in terms of melt viscosity, time stability, and char yield. Below 10 mol % of MA, the PAN copolymer exhibited no flowability, even at very low molecular weights (～ 20,000). The long‐range order inherently present in PAN is speculated to be broken down at a critical value of about 10% MA at 220°C in the PAN‐based system, enabling its melt flowability. It was also seen that the incorporation of MA was seen to improve the temperature and molecular weight window of processability of the PAN system. The molecular weight cutoff for the 90/10 mol % acrylonitrile/methyl acrylate (AN/MA) system was about 50,000 at 220°C, whereas it was increased to about 100,000 in the presence of 15 mol % MA comonomer. Feasibility studies on the use of other comonomers such as higher acrylates and acrylamides were also conducted. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 69–83, 2002     

低熔点双组分合金填充聚烯烃结晶性能研究

利用广角X射线衍射分析仪对低熔点金属及合金填充聚合物材料体系的结晶行为进行了研究。试验结果表明,少量的金属提高了树脂的结晶度,大量的金属加入破坏聚合物的结晶,极性聚合物阻碍合金结晶;较高的成型加工温度有利于体系的结晶性能的提高;第3组分加入使体系的结晶度减少、韧性变好。     

模拟技术在吹塑型坯成型中的研究进展

介绍了模拟技术在吹塑型坯成型中的研究和发展状况，针对型坯成型过程，对国内外学者进行数值分析的方法和理论依据进行了论述，着重论述了神经网络方法。并指出型坯成型是吹塑过程的核心，是一个受聚合物材料性能、熔融温度、成型加工条件等因素综合影响的过程。     

熔窑内玻璃液流动与传热的模型实验

熔窑内玻璃液流动与传热的模型实验赵国昌，胡桅林，陈泽敬，过增元（清华大学工程力学系１０００８４）ＭｏｄｅｌＥｘｐｅｒｉｍｅｎｔｆｏｒＧｌａｓｓＭｅｌｔＦｌｏｗａｎｄＨｅａｔＴｒａｎｓｆｅｒｉｎＴａｎｋＦｕｒｎａｃｅ￥ＺｈａｏＧｕｏｃｈａｎｇ；ＨｕＷｅ...     

熔体浸渍技术制备SiCp/AlN复合材料

采用熔体浸渍技术，研究了在高纯氮气氛下Al—Mg—Si合金反应浸渍碳化硅预形体制备SiCp／AlN复合材料．借助XRD，SEM／EDS，EMPA等测试手段检测了产物的物相组成，观察了材料的微观形貌，并对复合材料微区成分进行了分析。结果表明：1200℃下，在氮气气氛中用Al—Mg—Si合金反应浸渍碳化硅形成了SiCp／AlN复合材料。在氮化温度下，Al—Mg—Si合金中的Mg元素极易蒸发，与气氛中的微量氧发生反应，起到深脱氧作用，而Si元素的存在使Al—Si熔体容易浸渍渗透进入SiC预形体中，同时氮化反应生成AIN，形成了以AIN／Si为三维骨架，SiC呈孤岛状结构的SiCp／AlN复合材料。生长前沿氮化铝以胞状方式生长，胞内由呈放射状生长排列的柱状晶氮化铝构成，柱晶之问有大量的通道间隙，Si元素在胞内呈不均匀分布，胞边缘部分的硅含量明显高于胞中心部分，这与柱状氮化铝的生长机理有关。     

热塑性医用矫形绷带用热熔胶的研制

以聚己内酯(PCL)为主要原料制备了自粘型医用矫形绷带用热熔胶,确定了填料和稀释剂的用量,同时对最佳涂布量做了选择。利用该热熔胶制得的绷带具有反复多次使用的特点。