乙醇酸生产技术的研究进展

首先概述现有的几种工业生产乙醇酸的方法,即氯乙酸水解法、羟基乙氰水解法、甲醛羰基化法、草酸电解法等,虽然能生产乙醇酸,但不符合安全环保理念;综合分析了当前改进乙醇酸生产技术路线的研究方向,如乙二醛氧化法、甲醛与甲酸或甲酸甲酯偶联法、草酸二甲酯加氢法、乙二醇选择性氧化法、微生物法;最后指出,乙醇酸工业生产的最佳发展方向,应当是以乙二醇为原料选择性氧化生产乙醇酸。     

酚醛缩聚乙二醇铁聚合物的制备及其性能

采用三氯化铁改性酚醛缩聚乙二醇（PRG）,制得酚醛缩聚乙二醇铁聚合物（PRG-Fe）;并探讨了PRG与FeCl3物质的量比、反应温度、反应时间和加料顺序对反应及产物性能的影响,确定最佳制备工艺条件,同时对涂膜性能进行了研究。结果表明,PRG中酚羟基与金属铁离子发生配位反应,形成交联度更大的网状结构聚合物。因此,PRG-Fe易固化成膜,该涂膜具有优良的物理机械性能、热稳定性及防腐性能。     

RbBr-PEG（600）-H2O三元体系在多温下的相平衡研究

采用自制的半微量相平衡装置,测定了RbBr-PEG（600）-H2O三元体系在25℃、30℃和35℃下的等温平衡溶解度,同时测定了不同PEG含量下溶液的密度和折光率．结果表明：该体系在所研究的温度下均没有出现分层现象,RbBr的溶解度随温度的升高而增加,在同一温度下RbBr的溶解度随聚乙二醇含量的增加呈单调下降趋势．用四参数方程对溶解度进行了拟合．     

Surface modification of polycarbonate urethane by covalent linkage of heparin with a PEG spacer

Heparin was grafted onto polycarbonate urethane (PCU) surface via a three-step procedure utilizing α, ωdiamino-poly(ethylene glycol) (APEG, M n =2 000) as a spacer. In the first step, isocyanate functional groups were introduced onto PCU surface by the treatment of hexamethylene diisocyanate (HDI) in the presence of di-n-butyltin dilaurate (DBTDL) as a catalyst. In the second step, APEG was linked to the PCU surface to obtain the APEG conjugated PCU surface (PCU-APEG). In the third step, heparin was covalently coupled with PCU-APEG in the presence of N-hydroxysuccinimide (NHS) and 1-ethyl-3-(3-dimethylamidopropyl) carbodiimide (EDAC). The amount of heparin (1.639 μg/cm 2 ) covalently immobilized on the PCU-APEG surface was determined by the toluidine blue method. The modified surface was characterized by water contact angle, attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). The hemocompatibility was preliminarily studied by platelet adhesion test. The results indicated that heparin was successfully grafted onto the PCU surface, and meanwhile the hydrophilicity and hemocompatibility of the modified PCU surface were improved significantly compared with the blank PCU surface.     

A review of conservation treatments of waterlogged basketry from the northwest coast of North America

Abstract

Basketry artifacts fabricated from spruce and cedar limb wood and root and the inner bark of yellow and western red cedar have been found in water-saturated archaeological sites in the Pacific Northwest since the mid-twentieth century. These artifacts range in age from a few centuries to more than 5000 years old. While these materials retain their overall physical structure due to burial in an anoxic environment they are degraded on the cellular level. Experiments and treatments performed by archaeologists and conservators over the past 50 years have attempted to stabilize these degraded structures and minimize splitting, crumbing, and distortion of the woven structures as they dried. Many of these tests and treatments are published in out-of-print conference proceedings or remain unpublished in conservation lab records. This review of tests and treatments as well as a current condition assessment of several collections brings this information together for the first time and allows conservators and archaeologists specializing in these treatments to see the broader arch of success and failure of the preservation of waterlogged basketry materials.     

聚乙二醇型双联表面活性剂的合成工艺研究

以硬脂酸和聚乙二醇为原料,经酯化后生成聚乙二醇双酯。再经磺化剂氯磺酸的磺化作用下得α-磺基硬脂酸聚乙二醇双酯,加NaOH中和后成盐,形成α-磺基硬脂酸聚乙二醇双酯钠盐。实验结果表明,在催化剂用量为2.0%(基于反应体系的质量分数),酸醇的量比为2.5∶1.0,反应时间为4小时,反应温度140~150℃时,聚乙二醇双酯收率达83%。磺化剂氯磺酸与双酯的量比为2.4∶1.0,反应时间为1小时,反应温度为60~70℃,α-磺基硬脂酸聚乙二醇双酯收率为96%。α-磺基硬脂酸聚乙二醇双酯钠盐的总收率为79.7%。     

全氟磺酸树脂催化合成丁酮乙二醇缩酮的研究

以废弃的全氟磺酸树脂为催化剂,丁酮和乙二醇为原料合成了丁酮乙二醇缩酮。实验表明：当最佳醇酮摩尔比为2：1,催化剂用量为0．5g,反应时间为2h,带水剂用量为9．7mL时丁酮乙二醇缩酮的最高产率可达到87.3％。该催化剂绿色环保且易于回收,重复使用五次产率仍可达到81．1％。     

阿维菌素缓释固体分散体的制备及其性能研究

以聚乙二醇6000为载体,用熔融法制备了阿维菌素缓释固体分散体,并对其缓释性能和防紫外光降解作用进行了研究。结果表明,所制备的缓释固体分散体中,聚乙二醇6000对阿维菌素具有良好的包埋作用,包埋率可达94.23%~99.52%;阿维菌素的释放量随着温度的上升而上升,并具有良好的防紫外光降解的作用,其累积释放动力学方程为ARP=-91.6716 e-0.1022 t+98.1953,符合一级动力学释放模型。     

新戊二醇副产甲酸钠回收利用工艺

将新戊二醇副产甲酸钠在真空条件下加热至145~155℃,干燥4~7小时,干燥蒸出的水蒸汽和新戊二醇蒸汽用水吸收,吸收所得的水溶液通过脱水和精馏,制得的新戊二醇符合HG/T2309—92标准;干燥所得的甲酸钠同硫酸反应,所制得的甲酸符合GB/T2093—93标准。该方法既可回收甲酸钠中的新戊二醇,又可降低生产甲酸时甲酸钠的消耗,具有良好的经济效益和社会效益。     

不同种金银花幼苗对水分胁迫的生理反应

采用聚乙二醇人工模拟水分胁迫的方法,研究了不同种金银花幼苗对水分胁迫的生理反应过程．结果表明,随着水分胁迫的加剧,麻江和花溪2金银花游离脯氨酸含量先上升后下降,内蒙古金银花先下降后略有上升,游离脯氨酸对水分胁迫的反应机制不同．水分胁迫下各金银花丙二醛含量增加,增加幅度不同,贵州麻江金银花显示出较强的耐旱能力．