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以环烷酸镍(简称Ni)/三异丁基铝(简称Al)为催化体系,对自制的苯乙烯-异戊二烯-丁二烯三元无规共聚物(SIBR)进行加氢反应,确定了加氢反应条件,并对氢化SIBR进行了表征。结果表明,Al/Ni(摩尔比)变化时,SIBR中聚丁二烯链段的1,2-结构比1,4-结构易于加氢,聚异戊二烯链段的3,4-结构比1,4-结构更易加氢;在催化剂用量为2 mg/g、Al/Ni为7、反应温度为60℃、反应压力为4 MPa的条件下,SIBR的最高加氢度可达98%;氢化SIBR的数均分子量和重均分子量均比SIBR略有增大,分子量分布亦略有变宽,但仍呈现窄分布的特点;SIBR中聚丁二烯链段和聚异戊二烯链段均已发生氢化反应,而苯乙烯链段基本不发生氢化反应,说明该催化体系具有较高的催化活性和选择性。 相似文献
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氮官能化多锂引发合成星形苯乙烯-异戊二烯-丁二烯共聚物的微观结构和玻璃化转变温度 总被引:1,自引:1,他引:0
以六亚甲基亚胺锂(LHMI)与二乙烯基苯(DVB)合成的氮官能化多锂(简称Li)为引发剂,N,N,N′,N′-四甲基乙二胺(TMEDA)为极性调节剂,环己烷为溶剂,制备了带有氮官能化基团的星形无规苯乙烯-异戊二烯-丁二烯共聚物(SIBR),用核磁共振法进行了表征,并分析了TMEDA用量、聚合温度、引发剂浓度及DVB/Li(摩尔比)对SIBR微观结构和玻璃化转变温度(Tg)的影响。结果表明,在DVB/LHMI(摩尔比)为0.8的条件下,SIBR中有C—N存在,并且为臂数不等的星形聚合物;随着TMEDA用量的增加和聚合温度的降低,SIBR中非1,4-结构含量增加,Tg提高;在实验范围内引发剂浓度和DVB/Li对SIBR中非1,4-结构含量和其Tg影响不大。 相似文献
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以六亚甲基亚胺锂(LHMI)与二乙烯基苯(DVB)合成的氮官能化多锂(简称Li)为引发剂,N,N,N’,N’-四甲基乙二胺(TMEDA)为极性调节剂,环己烷为溶剂,制备了带有氮官能化基团的星形无规苯乙烯-异戊二烯-丁二烯共聚物(SIBR),用核磁共振法进行了表征,并分析了TMEDA用量、聚合温度、引发剂浓度及DVB/Li(摩尔比)对SIBR微观结构和玻璃化转变温度(Tg)的影响。结果表明,在DVB/LHMI(摩尔比)为0.8的条件下,SIBR中有C-N存在,并且为臂数不等的星形聚合物;随着TMEDA用量的增加和聚合温度的降低,SIBR中非l,4-结构含量增加,Tg提高;在实验范围内引发剂浓度和DVB/Li对SIBR中非1,4-结构含量和其,Tg影响不大。 相似文献
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以自制的4种苯乙烯-异戊二烯-丁二烯橡胶(SIBR)为增韧组分,采用本体聚合工艺,以过氧化苯甲酰为引发剂进行苯乙烯接枝聚合以制备高抗冲聚苯乙烯,考察了用量、相对分子质量及分子链结构不同的SIBR对苯乙烯聚合速率的影响,并比较了用不同橡胶改性聚苯乙烯时的聚合动力学行为。结果表明,SIBR的用量越大聚合速率越小,相对分子质量越大则聚合速率越大;按SIBR分子链序列结构的不同聚合速率还呈现出从大到小依次为线型嵌段SIBR、线型无规SIBR、星形嵌段SIBR及星形无规SIBR的规律。用不同橡胶增韧聚苯乙烯时的聚合速率从大到小依次为SIBR、丁苯橡胶及顺丁橡胶。苯乙烯的表观接枝率随着SIBR用量或其相对分子质量的增大而减小,且远大于使用顺丁橡胶。 相似文献
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以n-BuLi为引发剂、乙基四氢糠基醚(ETE)和十二烷基苯磺酸钠(SDBS)二元复合调节体系为调节剂、己烷/环己烷为混合溶剂,在聚合温度为50 ℃时采用负离子聚合法进行苯乙烯-异戊二烯-丁二烯(SIBR)三元共聚合,考察了ETE/n-BuLi(摩尔比)和SDBS/n-BuLi(摩尔比)对SIBR微观结构含量和玻璃化转变温度(Tg)的影响。结果表明,当ETE/n-BuLi从0.5增加到2.0、SDBS/n-BuLi为0.1时,SIBR中聚丁二烯的1,2-结构质量分数和聚异戊二烯的3,4-结构质量分数分别增加了5.4和7.6个百分点,Tg上升了28.84 ℃左右;当SDBS/n-BuLi从0.1增加到0.8、ETE/n-BuLi为0.5时,SIBR中聚丁二烯的1,2-结构含量、聚异戊二烯的3,4-结构含量和Tg变化很小;ETE调节SIBR中聚丁二烯的1,2-结构和聚异戊二烯的3,4-结构的能力远远大于SDBS。 相似文献
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以正丁基锂为引发剂,环己烷为溶剂,双四氢糠丙烷为结构调节剂,四氯化锡为偶联剂,采用负离子聚合法合成了锡偶联型苯乙烯-异戊二烯-丁二烯三元共聚物(SIBR)。通过核磁共振波谱仪、差热分析仪及黏弹谱仪等对聚合产物的微观结构、玻璃化转变温度、力学性能及动态力学性能等进行了分析测试。结果表明,随着双四氢糠丙烷与正丁基锂摩尔比的增大,SIBR中的1,2-聚丁二烯和3,4-聚异戊二烯结构含量明显增加,而1,4-聚丁二烯和1,4-聚异戊二烯结构含量明显减少;侧基含量和玻璃化转变温度均明显升高;0℃的损耗因子明显增大,而60℃的损耗因子均小于0.12;总体上对SIBR硫化胶力学性能的影响不大,SIBR硫化胶的拉伸强度均超过了19 MPa,300%定伸应力大于12 MPa,扯断伸长率大于350%,能够满足高性能轮胎对胎面胶的要求。 相似文献
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以正丁基锂为引发剂、四氢呋喃为结构调节剂、环己烷为溶剂、四氯化锡为偶联剂,采用负离子溶液聚合法合成了不同苯乙烯(St)/异戊二烯(Ip)/丁二烯(Bd)(质量比)的无规星形St-Ip-Bd橡胶(SIBR); 考察了不同单体比对SIBR性能的影响,并与国产溶聚丁苯橡胶(SSBR)1204进行了对比。结果表明,不同单体比的SIBR混炼胶的加工性、挤出外观均优于SSBR 1204,硫化速率快于SSBR 1204; 在本实验条件下,不同单体比的SIBR试样之间在混炼性能上没有明显区别,而硫化胶的力学性能和动态力学性能之间有一定差别; SIBR的抗湿滑性能优于SSBR 1204,而滚动阻力相近。 相似文献
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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。 相似文献
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D. G. Gordeev L. F. Gudarenko M. V. Zhernokletov V. G. Kudel’kin M. A. Mochalov 《Combustion, Explosion, and Shock Waves》2008,44(2):177-189
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.
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Translated from Fizika Goreniya i Vzryva, Vol. 44, No. 2, pp. 61–75, March–April, 2008. 相似文献
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Jorge Marcelo Romero Soledad Bustillo Hugo Enrique Ramirez Maisuls Nelly Lidia Jorge Manuel Eduardo Gómez Vara Eduardo Alberto Castro Alicia H. Jubert 《International journal of molecular sciences》2007,8(7):688-694
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. 相似文献
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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%. 相似文献
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塔设备改造选型的分析 总被引:2,自引:0,他引:2
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)。 相似文献
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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 相似文献