Thermally Stable and Well‐Defined Pentadiene‐Derived Copolymers Prepared by Anionic Alternating Copolymerization and Subsequent Controlled Postmodification

Thermally stable and well‐defined hydrocarbon polymers prepared via anionic alternating copolymerization of 1,3‐pentadiene (P monomer: trans (TP) and cis (CP) mixture) and styrene derivatives (S monomer: styrene (St) and 1,1‐diphenylethylene (DPE)) and subsequent hydrogenation and cationic cyclization modifications are reported. The TP/S/CP terpolymerization reveals that an incorporation of S‐alt‐CP sequence into the alternating chain is more favorable, while the S‐alt‐TP insertion is also possible especially under high temperature owing to their competitive energy barriers and thermodynamic properties. Then the resultant copolymers with equimolar amount of the two monomers and predominant linear units are intramolecularly cyclized with CF₃SO₃H, or hydrogenated with p‐toluenesulfonyl hydrazide, to afford soluble and thermally stable hydrocarbon polymers with controlled Mns and narrow ?_Ms. The T_g of cylized polymer increases dramatically (ΔT_g > 100 °C) on cyclization between the adjacent C?C bond in the P structure and the aromatic ring of S unit through the intramolecular Friedel–Crafts alkylation. On the other hand, the T_g of hydrogenated product slightly decreases (ΔT_g ≈ 10 °C) after 98% hydrogenation due to the increasing flexibility of the saturated main‐chain, while the Td increases about 60 °C due to the loss of C?C bonds under oxygen atmosphere.     

5-羟基萘满酮的合成

以1，5－萘二磺酸钠为原料，先以碱熔法制得1，5－萘二酚，进而以雷尼镍为催化剂，在水溶液中于70－90℃常压氢化得到合成青光眼治疗药物左布诺洛尔的原料5－羟基萘满酮。方法操作简便，成本较低，总收率41．6％。     

催化加氢法制3,4-二氯苯胺的工艺研究

OBJECTIVE To optimize the process of catalytic hydrogenation of 3,4-dichloronitrobenzene.METHODS Did serial comparative experiments according to the selected main interacting factors,such as temperature,pressure,dose of catalyst,volume of solvent,and reac     

氢化单元反应生产场所安全设计要点

氢化反应是一种常用的化学单元反应,许多药品和化工产品的生产工艺过程中都会应用到这一反应.由于使用的原料为氢气,故这一反应过程具有一定的危险性存在.但只要我们安全预防措施规范到位了,完全可以控制在安全生产范围之内的.文章全方位地阐述了氢化反应生产场所安全措施要点.     

Low-cost acetate-catalyzed efficient synthesis of benzimidazoles using ambient CO2 as a carbon source under mild conditions

Using CO₂ as a low-cost C1 resource to produce value-add products was considered as a promising strategy for the sustainable carbon cycle. Herein, a base-promoted reductive functionalization of CO₂ and 1,2-phenylenediamine for the synthesis of benzimidazole was developed using hydrosilane as an H-donor. Commercially available acetate salt CH₃COOK used as a budget catalyst could furnish various benzimidazoles with moderate to excellent yields (42-95%) under mild conditions (40 °C, 1 bar CO₂). The reaction mechanism undergoing cascade N-formylation, cyclization, and reduction was preliminarily confirmed by attenuated total reflection (ATR) technique and control experiments.     

苯二酚酯类液晶的合成和性能研究——Ⅱ.高负性液晶反-4′-烷基环己烷羧酸-2,3-二氰基-4-正丙氧基苯酚酯的新合成法及其性能

以苯和对苯醌为初始原料,经多步反应合成了下列结构的化合物改变了中间体4-正丙氧基-2,3-二氰基苯酚(Ⅱ)的合成方法,以2,3-二氰基对苯二酚为原料,通过PTC-Williamson反应合成了新的化合物4-烯丙氧基-2,3-二氰基苯酚(Ⅲ)(产率66%)。对Ⅲ进行选择性催化氢化,得到Ⅱ(产率95%以上)。两步总产率62%以上,较一般的Williamson合成法产率高20%以上。测定了Ⅰ的相变温度和介电各向异性等,结果表明,这是一类适于配制室温负性液晶材料的单体液晶。     

不锈钢堆焊层抗剥离性能的定量评价

提出了定量评价堆焊层抗离性能的指标“开裂氢浓度Cdc”。研究结果表明，在不同试验条件下，对同一批堆焊试块的剥离性能进行评价，所得到的Cdc值基本上为一常量。因此，可将Cdc作为定量评价的参量。这种评价方法还能将堆焊试块的试验结果与役反应器堆焊层的剥离问题联系起来。     

在Pd/γ-Al2O3催化剂上液相苯加氢的反应动力学

采用Pd／γ-Al2O3催化剂，在排除扩散影响的条件下，研究了液相苯催化加氢制环己烷的反应动力学。实验测定了反应温度、氢气压力、反应物浓度等因素对反应速率的影响，反应温度研究的范围为393～453K，氢气压力为1．1～3．8MPa。研究结果表明，液相苯加氢反应对苯表现为零级，对氢压表现为一级，反应活化能为43．88kJ／mol。运用该动力学模型对在较低苯浓度下进行的加氢反应进行了预测，预测值与实验值能较好地吻合。     

某石化企业重整加氢装置职业病危害因素调查

目的通过了解某石化企业重整加氢装置工作场所产生的职业病危害因素水平与分布,分析采取的职业病防护措施,探讨重整加氢装置运行过程中职业病危害的关键控制点和关键控制措施,为该类工程的职业病防治管理提供依据。方法采用职业危害现场调查、系统工程分析、现场检测、实验室分析等方法进行综合分析与评价。结果该装置生产过程中存在的主要职业病危害因素为苯、甲苯、二甲苯、溶剂汽油、液化石油气、戊烷、硫化氢等化学毒物及噪声、高温等物理因素。检测结果表明,工作场所中化学有害物质浓度均远低于国家卫生限值要求,各个监测点噪声强度合格率均为100%。结论该装置采取的防毒、防噪、防高温等设施可行、有效。企业的日常管理中应杜绝管道、阀门、塔、罐等装置的跑、冒、滴、漏,并加强作业人员的个体防护。     

第Ⅲ类压力容器加氢主反应器风险评估报告

按照《固定式压力容器安全技术监察规程》（TSGR0004—2009）第3.6条和GB150《固定式压力容器》征求意见稿附录G要求,对加氢主反应器可能发生的危害、损伤机理及主要特征进行分析,并提出预防损伤的措施。