THERMOPLASTIC,FLEXIBLE, AND RECYCLABLE COMPOSITES,DESIGN, PREPARATION,AND CHARACTERIZATION

Glass fiber reinforced composites based on thermosets are the traditional materials used for many applications due to their good mechanical properties. The non-recyclability of these materials has led to the necessity to develop thermoplastic composites and industrial processes for their manufacture [1]. The present paper deals with the preparation of thermoplastic pre-pregs unidirectionally reinforced with Twarn® and their mechanical characterization.     

DUO-ICP-AES测定精对苯二甲酸中的钴、铬、铁、锰、钼、镍、钛

采用DUO-ICP-AES同时测定精对苯二甲酸中钴、铬、铁、锰、钼、镍、钛,并对仪器的分析线选择、背景校正、入射功率、雾化器压力、辅助气流量、冷却气流量、蠕动泵转速的影响及共存元素的干扰、硝酸铯灰化助剂等因素进行了详细的研究。方法的检测限:钴0.0097 mg/L;铬0.0021 mg/L;铁0.0078 mg/L;锰0.0012 mg/L;钼0.0027 mg/L;镍0.016 mg/L;钛0.0027 mg/L,回收率和精密度分别为93.0%～99.5%和0.37%～3.2%。该方法快速简便,具有良好的精密度和准确度,适用于进出口精对苯二甲酸的日常检验。     

Pd-, Ni-, Fe-, and Co-Catalyzed Cross-Couplings Using Functionalized Zn-, Mg-, Fe-, and In-Organometallics

The development of new methods for preparing polyfunctional organometallics has made a broad range of such reagents available for various transition metal-catalyzed cross-couplings. An overview of the most general preparation methods will be presented. Applications to practical cross-coupling procedures will be covered, emphasizing the functional group compatibility and the reaction scope.     

N,N''''-双甲基-N,N''''-双(2,3,4,5,6-五羟基正己基)-2,3,5,6-四碘对苯二甲酰胺的合成

以对苯二甲酸和碘为原料,50%发烟硫酸为溶剂,制得2,3,5,6-四碘对苯二甲酸,再通过氯化亚砜进行酰氯化,最后与葡甲胺反应合成了标题化合物.其结构通过元素分析、红外光谱、核磁共振氢谱,质谱得到确证.运用正交实验优化了酰胺化反应条件三乙胺为缚酸剂,四碘对苯二甲酰氯和葡甲胺为反应物,它们的物质的量比为2.112.4,反应温度为40℃时,产率高达71.5%.     

Sylvatraxx树脂对半钢子午线轮胎胎面胶性能的影响

本文研究了Arizona Chemical公司生产的胎面增强助剂（Tread Enhancement Additive-TEA）Sylvatraxx 4401对半钢子午线轮胎胎面胶性能的影响。结果表明：Sylvatraxx 4401的加入有利于提高白炭黑的分散性,改善混炼胶的加工性能和硫化胶的物理机械性能,能够明显提高胎面的抗湿滑性。随着Sylvatraxx 4401用量的增加,白炭黑在胶料中的分散进一步提高,混炼胶的门尼粘度降低;硫化胶的压缩生热和阿克隆磨耗降低,0oC的tanδ明显提高的同时60oC的tanδ略微降低,有利于胎面胶抗湿滑性能的提高和滚动阻力、动态生热的降低。     

Continuous solvent extraction of sunflower,seed, groundnuts,palmkernels, rapeseed,and copra

In principle, the oil milling process is straightforward. The wide variety of equipment in use reflects, however, a multiparametric process. The main limiting parameters are kind of seed, oil content, particle strength, particle structure, temperature, moisture, particle size, residence time, mechanical forces, etc. Additionally, the seed specific parameters vary not only between kinds of seed but also for the same seed, due to different conditions in climate, soil, and harvesting. Therefore, equipment design must be widely based on statistical averages of the limiting parameters. In other words, exact precalculation of the single technological steps is impossible. As a consequence, for more than 5,000 years, the oil milling process has been in the stage of being optimized. The acutal technical standard is very satisfying, but there is still a strong need for further research and development. Currently, as in the past, the oil milling process seems to be not so much a science as an art.     

Synthesis of methyl,propyl, butyl,isobutyl, hexyl,cyclohexyl, octyl,and 2-ethylhexyl esters of epoxyoleic acid

A series of esters of 12,13-epoxyoleic acid were prepared by means of alcoholysis of triepoxyolein (trivernolin). The procedure for the alcoholysis, and isolation and purification of the esters are described. Analytical characteristics of the esters are reported. E. Util. Res. Devel. Div., ARS, USDA.     

Preparation, Characterization, and Microwave Properties of RETiNbO6 (RE = Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Y, and Yb) Dielectric Ceramics

Microwave ceramic dielectric resonators (DRs) based on RETiNbO₆ (RE = Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Y, and Yb) have been prepared using the conventional solid-state ceramic route. The DR samples are characterized using XRD and SEM methods. The microwave dielectric properties are measured using resonant methods and a net work analyzer. The ceramics based on Ce, Pr, Nd, and Sm have dielectric constants in the range 32–54 and positive coefficient of thermal variation of resonant frequency (τ_f). The ceramics based on Gd, Tb, Dy, Y, and Yb have dielectric constants in the range 19–22 and negative τ_f.