Ring‐opening polymerization of lactones initiated by diphenylzinc–coinitiator systems

Diphenylzinc, alone or in combination with water and butanone as coinitiators, was used as a polymerization initiator system for a variety of lactones at varying temperatures. The resulting data indicate that the course of the polymerization is greatly influenced by the lactone structure, as well as by the molar ratio of coinitiator to diphenylzinc. When used alone, diphenylzinc exhibited high activity as an initiator in δ‐valerolactone polymerizations, although it was less efficient when used in the β‐butyrolactone and the β‐propiolactone polymerizations. Activity in the polymerization of β‐lactones was increased by adding small amounts of butanone or water. It was also observed that the diphenylzinc–butanone combination was more effective than the diphenylzinc–water mixture in the polymerizations of β‐butyrolactone and β‐propiolactone. Copyright © 2003 Society of Chemical Industry     

面积坐标法构造含转角自由度的四结点膜元

以四边形面积坐标作为工具,构造了两个含转角自由度的广义协调四边形单元AQ4和lAQ4。它们通过强式分片检验,与同类单元相比,具有很高的计算精度,能消除梯形闭锁现象,有很强的抗网格畸变的能力。     

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     

小井距开发现河油田低渗油藏可行性研究

认为注采井网井距大,水驱控制程度差,采收率偏低是影响胜利油田现河低渗透油藏开发的关键,通过井间密度与水驱控制程度和采收率的关系等分析,提出了现河低渗透油藏开发的合理的井网密度。     

饼干炉湿度控制的改进方法

在大空间的温度控制系统中 ,采用简单的PID控制规律 ,对空间的温度、湿度进行解藕计算 ,将空间的相对湿度控制转化为送风含湿量的控制。该控制方式稳定、可靠 ,并且节约能源。本方法适用于所有的烘烤炉中     

碳黑对苯乙烯自由基聚合反应影响的研究

研究了碳黑对苯乙烯单体聚合物反应的影响，结果表明，用过氧化苯甲酰作引发剂，普通碳黑子对苯乙烯的聚合有强烈的阻聚作用，而用偶氮二异丁腈引发聚合物时，普通碳黑的阻聚性很小，当时碳黑进行接枝处理后，接枝碳黑对苯乙烯自由基聚合的影响程度与接枝方法有关，其中过氧化苯甲酰 自由基枝枝碳黑的聚性变化较大。     

Kinetics of two-step anionic polymerization

This article deals with the kinetics of two-step anionic polymerization by way of a non-steady state method. Several molecular parameters can be evaluated using the formulae developed. A bimodal molecular weight distribution function for the resulting polymer is derived from the set of kinetic differential equations, which is in agreement with the experimental data reported.     

聚合物载体－稀土金属络合物的研究 ⅩⅢ．聚［苯乙烯－甲基丙烯酸β（甲基亚硫酰基）乙酯］的结构与其稀土金属络合物催化丁二烯聚合的活性

从测得的竞聚率计算了单体链节在聚［苯乙烯－甲基丙烯酸β（甲基亚硫酰基）乙酯］（ＰＳＭ）中的序列分布。苯乙烯（Ｓ）或甲基丙烯酸β（甲基亚硫酰基）乙酯（Ｍ）的长序列的概率随着ＰＳＭ中相应单体含量的增加而增加。对于Ｓ和Ｍ摩尔分数大致相等的ＰＳＭ，单体链节的长序列分布函数值相接近。用与此结构相近的ＰＳＭ合成的稀土金属络合物，其催化活性不佳。在Ｍ短序列分布和Ｓ长序列分布较高的情况下，络合物的催化活性最好。所得聚丁二烯的微观结构与ＰＳＭ中单体单元的分布无关。     

Synthesis and properties of peroxy derivatives of epoxy resins based on Bisphenol A: Effects of the presence of boron trifluoride ethereate

Oligomers containing peroxy groups have been synthesized on the basis of epoxides reacting with tert–butylhydroperoxide in the presence of boron trifluoride etherate. Dependence of reaction rates upon the quantity of catalyst, temperature and also nature of hydroperoxide has been investigated: A kinetic equation for the process has been formulated and also a kinetic scheme for the reaction taking into account the presence of boron trifluoride etherate is proposed. Structures of the synthesized peroxy oligomers have been confirmed by IR- and NMR-spectroscopy. The reaction initiating properties of the oligomers so synthesized were studied using as the example the styrene polymerization reaction. Electronic Publication