A new and efficient synthetic method of a liquid crystalline epoxy resin with biphenol and aromatic ester group

This article describes a high efficient and economical method to synthesize a liquid crystalline epoxy resin (LCER) containing biphenol and aromatic ester group, 3,3′,5,5′-tetramethylbiphenyl-4,4′-diyl bis(4-(oxiran-2-ylmethoxy) benzoate) (4). First, 3,3′,5,5′-tetramethylbiphenyl-4,4′-diyl bis(4-hydroxybenzoate) (3) was prepared by direct esterification of 3,3′,5,5′-tetramethylbiphenyl-4,4′-diol (2) with p-hydroxybenzoic acid (1) in the presence of a certain amount of p-toluene sulfonic acid (p-TSA) as catalyst. And then (4) was synthesized by the reaction of (3) with epichlorohydrin. The chemical structure, melting range, and liquid crystalline phase transition behavior of (4) were characterized by FT-IR, ¹H-NMR, ¹³C-NMR, mass spectroscopy, differential scanning calorimetry (DSC), and polarized optical microscopy (POM).     

输水管线大口径钢顶管施工技术措施

输水管线大口径长距离钢顶管施工中,技术措施的正确运用对保证质量安全、降低施工风险具有重大意义.该文从青草沙严桥支线DN3600双线钢顶管施工实践出发,介绍大口径钢顶管施工工艺中的几个问题和采取的对策,以期与同行进行交流和探讨.     

磺酸型水性聚氨酯分散液的制备方法与性能

叙述了磺酸型水性聚氨酯分散液的分散性、固含量以及胶膜性能,除与低聚物二元醇、二异氰酸酯、扩链剂种类及合成工艺有关外,与磺酸根在聚氨酯大分子中的引入方式密切相关.从磺酸根不同引入方式,即磺酸根是从链端引入还是在链上引入,链上引入又分软段引入和硬段引入,详细介绍了不同引入方式和制备磺酸型水性聚氨酯分散液的工艺及性能.     

在特色教材编写中突出“专业特色、产品特色与应用特色”——北京市精品教材立项项目“化工设备机械基础应用教程”

北京石油化工学院作为以培养高级应用型人才为主的二类本科院校,教材的选择与准确定位是实现教学目标的关键。我们在详细论述了北京市精品教材立项项目"化工设备机械基础应用教程"教材定位的基础上,提出了在教材的编写过程中突出"专业特色、产品特色与应用特色"的理念,为应用型本科教材的编写与出版进行了积极的探索。     

聚丙烯酸-丙烯酸丁酯-甲基丙烯酸二甲胺乙酯共聚物水性颜料分散剂的合成及应用

以丙烯酸(AA)、丙烯酸丁酯(BA)和甲基丙烯酸二甲胺乙酯(DM)为单体,合成了AA-BA-DM三元共聚物分散剂,研究了其对二氧化钛颜料的分散效果;讨论了分散剂黏度、分散剂用量对颜料分散体系的影响;同时考察了该共聚物分散剂对不同颜料的分散稳定性。结果表明,当n(AA):n(BA):n(DM)=1.25:1:0.15,引发剂占单体总质量的1%,链转移剂占单体总质量的4%,为聚合物分散剂的最佳合成条件,所得共聚物分散剂对二氧化钛分散效果最佳,分散力达97.5%,且分散剂的用量占颜料总质量的0.80%时分散效果较好。通过对酞菁绿、二氧化钛及铬红分散效果的考察,该分散剂对颜料酞菁绿的分散效果最好,二氧化钛次之,对铬红的分散效果较差。     

板壳式换热器的应用和进展

评述了近年来有关板壳式换热器的研究进展,着重介绍了板壳式换热器的结构、性能特点和制造技术.还介绍了板壳式换热器的工业应用情况.     

厌氧—两级SBR—混凝沉淀工艺在城镇小型垃圾填埋场渗滤液处理中的应用

针对垃圾渗滤液性质复杂多变难处理的特点以及城镇小型垃圾填埋场的实际情况,采用厌氧-两级SBR-混凝沉淀组合工艺处理浙江省岱山县生活垃圾填埋场渗滤液.连续40 d的运行结果表明,出水常规指标中除COD外,其余指标可通过优化运行条件基本达到生活垃圾填埋场污染控制标准( GB 16889-2008)要求.该处理工艺流程简单,运行稳定,费用合理,适合城镇小型垃圾填埋场渗滤液处理.     

Microwave-assisted synthesis of graphene-supported Pd1Pt3 nanostructures and their electrocatalytic activity for methanol oxidation

This work reports the development of a facile, one-step microwave heating method for the synthesis of graphene-supported Pd₁Pt₃ (Pd core/Pt shell) electrocatalysts. The structure and composition of the synthesized nanocomposites were characterized via transmission electron microscopy and atomic force microscopy as well as energy-dispersive X-ray, X-ray powder diffraction, FTIR, and Raman spectroscopies. Using voltammetry, the electrocatalytic characteristics of the graphene-supported Pd₁Pt₃ nanostructures were evaluated for the oxidation of methanol as a model reaction. The results show that the introduction of graphene increases the electrochemically active surface area of the Pd₁Pt₃ nanostructures. As compared to the unsupported Pd₁Pt₃ electrocatalyst, the graphene-supported Pd₁Pt₃ electrocatalyst exhibited 80% enhancement of the electrocatalytic specific mass current for the oxidation of methanol. This method may serve as a general, facile approach for the synthesis of graphene-supported bimetallic PtM electrocatalysts with increased utilization of the Pt metal, which is expected to have promising applications in fuel cells.     

AFM investigation of solid product layers of MgSO4 generated on MgO surfaces for the reaction of MgO with SO2 and O2

The nucleation, growth and arrangement of MgSO₄ product layers during the reaction of single-crystal MgO with SO₂ and O₂ were investigated via atomic force microscopy (AFM). The morphology of the single-crystal MgO surface after reacting with SO₂ and O₂ consisted of three-dimensional cone-shaped MgSO₄ product islands. Most of the islands appeared at locations with terraces, steps and kinks. With increasing reaction time, small product islands grew to large islands, finally coalescing into continuous islands. The nucleation, growth and arrangement of the solid products on the reactant surface are controlled by thermodynamics and kinetics. The morphology of the MgSO₄ product islands is governed by the competition between the intrinsic chemical reaction rate and the product molecular diffusion rate, which are both significantly affected by the reaction temperature. As the reaction temperature increases, the mean size of the MgSO₄ islands increases while the island density decreases. The nucleation, growth and arrangement of the solid product layers and the product layer morphology on the solid reactant surface directly affect the mechanism of the gas–solid reaction.     

微流控芯片测定盐酸倍他司汀片中盐酸倍他司汀

采用微流控芯片非接触电导检测法测定片剂中的盐酸倍他司汀.采用1 mmol·L-1HAc和2 mmol·L-1NaAc(pH 4.5)为缓冲溶液,0.1 mmol·L-1SDS为添加剂,以2.40kV分离电压,10 s进样时间,盐酸倍他司汀2 min内可实现快速分离和检测.盐酸倍他司汀的线性范围为10～140μg·mL-...