巯基乙酸盐在PVC中的稳定性研究

以巯基乙酸钡和巯基乙酸钡-钠作为稳定剂,添加到聚氯乙烯(PVC)中,通过刚果红实验法、热老化箱实验法和转矩流变仪等对PVC的静态与动态热稳定性能进行综合评价。结果表明:巯基乙酸钡和巯基乙酸钡-钠都能提高PVC的热稳定性,但巯基乙酸钡的稳定性要好于巯基乙酸钡-钠。     

PPE/EP体系的介电性能和耐溶剂性研究

利用扫描电镜、差示扫描量热仪以及高频介电仪研究了聚苯醚(PPE)/环氧树脂(EP)体系的相分离、耐热性和介电性能,并利用质量损失法研究了PPE/EP体系的耐溶剂性,结果表明:PPE/EP混合物的耐热性和介电性能均随着PPE含量的增加而提高,而耐溶剂性则随着PPE含量的增加而降低,在PPE/EP体系中加入三烯丙基异氰酸酯(TAIC)可有效地提高PPE/EP体系的耐溶剂性;当PPE含量大于30%时,PPE/EP混合物的介电性能显著提高,耐溶剂性显著下降。     

废旧塑料种类鉴别方法探讨

通过外观、密度、熔融、静电实验、溶解性实验、燃烧试验、热解试验、显色反应,并配合红外光谱分析仪,介绍了常见废旧塑料的鉴别方法及其优缺点,为塑料的回收利用提供帮助,并为开发新的鉴别方法提供了思路。     

PVC塑料电镀铜的研究

研究了工艺条件和添加剂对PVC塑料上电镀铜的沉积速度、硬度、结合力、耐蚀性、表面形貌等性能的影响。结果表明,PVC塑料上电镀铜的合理配方及工艺:CuSO4150g/L,H2SO440g/L,NaCl0.08g/L,0.015A/cm2,50℃,1.5h;较优单组分添加剂为:聚乙二醇-6000(50mg/L);最佳复合添加剂为:聚乙二醇-6000(50mg/L)+光亮剂OP-10(50mg/L)。     

铁盐对低密度聚乙烯光降解双重作用的研究

测定了铁盐/低密度聚乙烯(LDPE)薄膜的断裂伸长率保留率、表面结构、分子量和凝胶量,研究了不同添加量的铁盐对LDPE光降解的促进和抑制的双重作用。结果表明:铁盐添加量为0.1%时,对LDPE的光降解有促进作用,光照70天LDPE的黏均分子量从3.6×104下降到0.5×104;铁盐含量大于1%时,对LDPE光降解产生抑制作用。     

A photovoltaic-powered water electrolyzer: its performance and economics

A prototype water electrolyzer designed to operate from a solar photovoltaic (PV) array without power conditioning was operated for three months at the Florida Solar Energy Center. A 1 kWpk PV array was used to operate the electrolyzer at internal gas pressure from 0 to 40 psig. Performance of the electrolyzer/PV array was measured and characterized in terms of charge efficiency and power efficiency calculated from the operating data. The economics of residential production of hydrogen for energy purposes were calculated and summarized. While the near-term outlook for this energy storage technique was not found to be favorable, the long-term outlook was encouraging.     

导电高分子基柔性应变传感材料研究进展

随着人机交互、电子皮肤、可穿戴电子等新兴领域的迅速发展,作为核心部件之一的柔性应变传感材料成为人们关注的热点。由导电材料与柔性高分子复合而成的导电高分子基复合材料具有柔韧性好、质轻、易加工成型等优势,且材料导电性能在应变刺激下发生改变,因此可用作柔性应变传感材料。综述了基于导电高分子复合材料的柔性应变传感材料的分类及特点,详细介绍了该类传感材料的应变响应机理,并总结了影响导电高分子复合材料应变传感性能的因素。     

Kinetics of dissolution of synthetic scheelite by an alkaline EDTA leach solution

The dissolution rate of synthetic scheelite in an alkaline EDTA leach solution under atmospheric pressure has been determined by use of a rotating disc method. The effects of disc rotation speed, temperature, reagent concentration and pH of leach solution have been investigated. The dissolution rate was proportional to the square root of the disc rotation speed. The apparent activation energy of dissolution of synthetic scheelite was 22 kJ mol⁻¹ within the experimental temperature region of 24 to 99°C. A first order dependence of dissolution rate on EDTA concentration was observed. It has been shown from the experimental results that the dissolution reaction was controlled by the mass transfer in the aqueous solution.     

Energy analysis applied to food processing

We use first-law and second-law efficiencies on 2 multi-process food processing plants. These efficiencies are 59.6 and 19.4% for a condensed milk plant and 43.0 and 15.5% for the bakery plant. Improvements in both first-law and second-law efficiencies for the bakery can be achieved by reducing the mass of dough moulds and recovery of energy in the bake-oven exhaust to heat the air in the proofing oven. Replacement of the flash-cooling process in the condensed-milk plant by a combination of boiling at 100 °C and cooling via a vapour-compression refrigerator would lead to significant improvements in plant efficiencies.