茂金属催化 1-丁烯聚合反应动力学

以五甲基环戊二烯基三苄氧基钛犤Cp*Ti(OBz)3犦和改性甲基铝氧烷(mMAO)为催化体系,合成了立体有规聚1-丁烯,研究了不同聚合反应温度、催化剂浓度、1-丁烯浓度下的聚合反应动力学。结果表明,在聚合反应初期,聚合速率与催化剂浓度和单体浓度的一次方成正比,求得30,40,50℃下的聚合速率常数分别为3.19×104,2.75×104,2.25×104,碰撞因子为9.31×106,表观活化能为14.3kJ/mol。     

液体聚丁二烯的研制——Ⅱ.不同烷氧基碱金属对合成液体聚丁二烯的影响(下)

本工作以丁二烯为单体、二甲苯为溶剂兼作链转移剂、正丁基锂为引发剂、二乙醇二甲醚为添加剂,研究了不同烷氧基碱金属对聚合反应的影响。求出链转移次数(N_t)、链转移常数(C_(tr))、链增长速度常数(k_p)和链转移速度常数(k_(tr))的值,从而定量地判断出,在此体系中,N_t、C_(tr)和k_(tr)遵循以下顺序:t-BuOK>>t-BuONa>t-BuOLi;聚合增长速度的顺序为:t-BuONa>t-BuOK>t-BuOLi。反应中C_(tr)、k_p和k_(tr)均随温度的升高而增大;对t-BuONa和t-BuOK两体系而言,k_(tr)比k_p随温度而变化的幅度大。     

用FTIR研究聚氨酯弹性体的固化动力学

使用傅里叶变换红外光谱仪 ,原位跟踪了催化及未催化聚氨酯弹性体(PU)的固化反应动力学行为。结果表明 ,—NCO和—OH的本体聚合在反应初期遵循二级反应和催化动力学规律 ;未催化和催化的PU固化反应的活化能分别为48.0kJ/mol和38.86kJ/mol,频率因子分别为3.01×108 L/(mol·s)和1.14×108L/(mol·s)。     

TDI封端聚醚预聚物与胺类固化剂固化反应的研究

用FTIR对TDI-PPG-MOCA体系的固化过程进行了红外跟踪,对吸收峰进行了归属分析,研究了该体系在不同温度下反应程度与时间的关系、固化反应的活化能。结果表明:该固化反应为二级反应;当温度分别为25℃、80℃、100℃时,该反应的速度常数k依次为91.41、3.37×103和3.15×103(g·mol-1·h-1);反应的表观活化能为57.45kJ·mol-1。     

正丁基锂_丁二烯_二氧六环阴离子聚合体系的动力学研究

以二氧六环为溶剂,以正丁基锂为引发剂,在充氮条件下,利用膨胀计进行了丁二烯聚合增长反应动力学研究。结果表明,增长反应对单体浓度和活性种浓度的反应级数皆为一级关系;活化能为34.54kJ/mol,频率因子为2.44×10~7L·mol~(-1)·min~(-1);并求出生成1,4-和1,2-结构含量的分速度常数分别为k_3=7.70×10~7 e~(-9900/RT)L·mol~(-1)·min~(-1),k_4=9.44×10~6 e~(-7800/RT)L·mol~(-1)·min~(-1);同时求出在二氧六环溶剂中 1,2-结构含量与温度关系的经验公式为 a=85.39-0.178 t,指数关系式为a=0.387 e~(450/RT)。     

新型芳香二胺扩链剂DMTDA的"原位"扩链反应动力学研究

采用傅立叶变换红外光谱仪(FTIR)法"原位"跟踪了二胺扩链剂2,4/2,6-二氨基-3,5-二甲硫基甲苯(DMTDA)与异氰酸酯扩链反应的过程.实验结果表明,本体聚合反应中,在反应初期低转化率时,反应规律表现为良好的二级动力学关系,给出了反应初期的动力学常数.反应后期高转化率时,反应速率常数受温度影响较大.当温度较低时,反应受扩散控制影响,NCO和NH2反应的二级反应动力学速率常数逐渐变小;温度较高时,反应速率常数变大;DMTDA的本体聚合反应时活化能Ea为26.3 kJ/mol.100℃下DMTDA的反应初期的速率常数为3.7×10-3 kg/mol·s,其活性是MOCA的3.7倍.比较了常见二胺扩链剂的相对反应活性大小.     

中乙烯基聚丁二烯橡胶的聚合动力学研究

以n-BuLi(C)为引发剂,环己烷为溶剂,四氢呋喃(THF)或二乙二醇二甲醚(2G)为调节剂,研究了不同 THF/C或2G/C值时的中乙烯基聚丁二烯的聚合动力学。结果表明,聚合速度随 THF/C或 2G/C增加而迅速上升,在不同 THF/C或 2G/C值和不同聚合反应温度时,聚合反应速度与单体浓度皆为一次方关系,求得了不同THF/C或2G/C值时的表观增长反应活化能。     

异戊二烯在二氧六环中的负离子聚合动力学

研究了以正丁基锂为引发剂 ,异戊二烯在二氧六环溶剂中负离子聚合的动力学。结果表明 ,增长反应对单体浓度和引发剂浓度皆为一级反应 ,活化能为45.22kJ/mol,频率因子为4.832×108L/(mol·min) ,并求出了生成1,4 -结构、1,2 -结构和3,4 -结构产物的速率常数分别为2.77×1012exp( -74760/RT) ,9.82×106exp( -39190/RT) ,8.02×107exp( -41180/RT)。     

Cadion AP的合成及其与金属离子的显色反应

介绍了氨替比林基重氮氨基偶氮苯的合成方法。用光度法测定的它在 Triton X-100存在下的二级离解常数分别为(6.0±0.3)×10~(-2),(5.9±0.4)×10~(-12)。在 pH11.5时,与镉和汞的配合物的表观摩尔吸光系数分别是2.11×10~5L·mol~(-5)·cm~(-1)和1.61×10~5L·mol~(-1)·cm~(-1)。     

亚胺基二乙酸树脂对镨的吸附性能及其机理

研究了镨离子在亚胺基二乙酸树脂(D401)上的吸附行为,在pH5.73时吸附最佳。测得静态饱和吸附容量为162mg·g~(-1)(树脂);用0.1～3.0mol·L~(-1)_HCl可定量洗脱;表观速率常数k_(298)=2.96×10~(-5)s~(-1);表观活化能E_a=7.18kJ·mol~()-1;等温吸附服从Freundlich经验式;吸附热力学参数△H=10.4kJ·mol~(-1),△S=45.4J·mol~(-1)·K~(-1),△G=-3.10kJ·mol~()-1;树脂功能基与镨离子的配位摩尔比为3:1;用化学和红外光谱等方法探讨了吸附机理。     

乙烯酮(双乙烯酮)下游产品废水的治理技术

乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。     

几种乙炔加压设备性能的比较

阐述并比较了几种加压设备在乙炔加压清净过程中的性能和特点。     

三种煤样燃烧热的测定

本文通过三个厂家提供的三种煤样燃烧热的测定,由测定结果综合得出3号煤样燃烧最完全、燃烧热也最大,是三个煤样中最好的一种。     

Semi-empirical equation of state of metals. Equation of state of aluminum

A semi-empirical equation of state for metals is described. Its capabilities are demonstrated by the example of the equation of state for aluminum. New experimental data are presented on the location of the isentrope of aluminum for unloading from the state at p = 229.71 GPa on the shock adiabat to an aerogel (SiO₂) of density 0.08 g/cm³. __________ Translated from Fizika Goreniya i Vzryva, Vol. 44, No. 2, pp. 61–75, March–April, 2008.     

水泥水化热测定方法综述

水泥水化热是中、低热水泥和核电工程用水泥的一项关键的技术指标。全球范围内测定水泥水化热的方法有溶解法、直接法/半绝热法、等温传导量热法三种。本文总结了中、美、欧相关方法标准,对其测试原理、仪器设备、试验过程等方面进行了比对,并对其在领域的应用做了简单的概括。     

小议汽车涂装工艺设计对涂装成本的影响

论述了涂装工艺设计对涂装设备投资、涂装生产成本的影响。     

Measurement of the gradient of viscosity with composition of mixtures of non-ideal gases

A perturbation viscometer is a differential capillary viscometer that measures the logarithmic viscosity gradient of the viscosity-composition curve for gas mixtures. Measurements are made at different gas mixture compositions. Integration of the logarithmic viscosity gradients measured over the full composition range gives the mixture viscosity relative to the viscosity of one of the pure components of the gas mixture. This method is attractive because, for measurements of equal precision, integration of the gradients is potentially an order of magnitude more precise than measurement of the viscosities directly. It can also work at high and low temperatures and perhaps high pressures.The perturbation viscometer has been used to make measurements on ideal gas mixtures at ambient and elevated temperatures. The situation is more complicated when the gas mixtures are non-ideal. Extra effects due to density differences, molar volume change on mixing and differential thermal expansion may be measured in addition to the desired viscosity change producing systematic errors in the results. Thus, a more sophisticated apparatus is required. The standard perturbation viscometer has been modified to separate out the extra effects to permit measurement of the true change in viscosity. In addition, the theoretical operation of the modified apparatus has been revised to account for the design changes to permit calculation of the viscosity-composition profiles from the results.The apparatus has been tested using helium-HFC-125 mixtures and two new viscosity-composition profiles are presented for these mixtures at 23 and . Internal consistency tests have been used to confirm that the data produced are of high quality with an estimated uncertainty in the viscosity ratio data at of 0.9% and at of 1.5%.     

Calorimetric and Computational Study of Enthalpy of Formation of Diperoxide of Cyclohexanone

A thermochemical rather simple experimental technique is applied to determine the enthalpy of formation of Diperoxide of ciclohexanone. The study is complemented with suitable theoretical calculations at the semiempirical and ab initio levels. A particular satisfactory agreement between both ways is found for the ab initio calculation at the 6–311G basis This set level. Some possible extensions of the present procedure are pointed out.     

塔设备改造选型的分析

就当前扩产增容中塔设备设计和改造时板式塔和填料塔的选型问题加以分析。在评述目前国内常用的几种塔板和新型填料之后，着重介绍一种新型塔板（导向梯形浮阀塔板）和一种新型填料（波环填料——乾隆帕克）。     

Effect of degree of deacetylation of chitin on the properties of chitin crystallites

In the present article, chitin from crab shell was systematically deacetylated using a NaOH treatment with control of the reaction time. The degree of deacetylation, monitored using solid-state NMR, revealed that the reaction was pseudo-first order. Based on this, swollen and NaOH-saturated particles are proposed as the reaction system. The weight loss of the partially saponified and neutralized samples after HCl hydrolysis increased linearly with the degree of deacetylation. The crystallinity of the samples was found to increase after acid hydrolysis. According to conductimetric titration, the surface charge density of the crystallites, after acid hydrolysis, was found to increase with base treatment time. The effect of surface charge on the formation of a chiral nematic phase, due to the rodlike nature of the crystallites, was explored. These results show that because the contribution of charged particles to the ionic strength was significant the double layer compression was affected, especially since the surface charge density was close to the Manning limit. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65:373–380, 1997