Monte Carlo simulation of gas phase polymerization of 1,3‐butadiene. Part II: Kinetics optimization and confirmation

Studies on the deactivations and initiations of gas phase polymerizations of 1,3‐butadiene have been achieved by Monte Carlo simulation. Initiation and deactivation control the reaction before and after the peak of the polymerization rate, respectively. The influence of polymerization temperature has been studied. Monte Carlo modeling of polymerization kinetics and mechanism was confirmed by the agreement of experimental data and simulation results of polymerizations run with a temporary evacuation of monomer. The balance of catalysts and active chains is established by both initiation and chain transfer reactions with cocatalyst, which causes a ‘pseudo‐stability’ stage. © 2003 Society of Chemical Industry     

Phosphorus‐containing polyaryloxydiphenylsilanes with high flame retardance arising from a phosphorus–silicon synergistic effect

Polyaryloxydiphenylsilanes were prepared from phosphorus‐containing diols and diphenydichlorolsilane through solution polymerization. With a stoichiometric imbalance in feed monomers, the resulting polymers exhibited moderate melting points and good processing properties. The polymers prepared showed initial decomposition temperatures above 340 °C, excellent thermal stability, high char yields at 850 °C and very high limited oxygen index values of 56–59. The polymers' char yields and their (P + Si) contents showed linear relationships. © 2003 Society of Chemical Industry     

无机高分子絮凝剂聚硫酸铁合成条件的研究

实验研究了以工业硫酸亚铁及废硫酸为原料,分别采用NaClo_3、KClO_3、H_2O_2及(o_2+NaNO_2)为氧化剂成聚硫酸铁的条件。在以(O_2+NaNO_2)为氧化剂的合成过程中,发现添加微量助催化剂(型号为HG-1、HG-2和HG-3),对提高合成速度及反应过程的稳定性具有重大作用。     

A PC program for diagnosing abnormal growth, growth velocity and acceleration from longitudinal observations

A human fibroblastic cell line transformed by the SV40-T antigen sequence and continuously cultured for 7 months displayed large periodic variations in cell proliferation. This contrasted with other characteristics of this cell line that remained constant: mosaic cell shape, absence of cell contact inhibition, and predominance of a hypodiploid population. Similar fluctuations in proliferative capacity were also found during the long-term growth of a transformed but nonimmortalized human fibroblastic line prior to senescence, and in the established hamster fibroblastic Nil cell line. This growth pattern suggests a recurrent stimulation of growth in these three transformed cell lines. The proliferation pattern from cultured transformed cells may thus be complex and requires further investigation. These variations presumably influence major cell functions. This observation has important implications for the analysis of data from such cell lines.     

A new efficient method for one‐pot conversions of aryl carboxylic acids into nitriles without solvent

A new efficient method for synthesising nitriles, important organic reagents, is reported in this paper. In an environmentally benign solvent‐free system, aryl carboxylic acids were converted into the corresponding nitriles via one‐pot reactions, by amidation with ethyl carbamate followed by dehydration with thionyl chloride, in excellent yields. The results showed that the method has the advantages of lower cost, higher yield, less pollution and greater ease of work‐up. Copyright © 2008 Society of Chemical Industry     

高柔韧性尼龙1010材料的制备

对尼龙1010/NBR/增塑剂体系进行了系统研究,发现在挤出机中环氧扩链剂可以对尼龙进行扩链反应,且环氧树脂对尼龙1010的扩链反应活性较高,扩链效果比较明显;N-丁基苯磺酰胺是尼龙的良好增塑剂,经增塑、增韧后可以使经扩链后的尼龙1010柔韧性有明显提高.采用SEM和TEM对所制备的材料进行了形貌分析,发现用NBR增韧尼龙,对于不同的基体材料,橡胶粒子的形貌有很大不同,粒子由增韧纯尼龙的椭球形变为在增塑尼龙基体中不规则的形状.