Separation of Trimethyl Borate from a Liquid Mixture by Pervaporation

Four commercial polyvinyl alcohol (PVA) and polydimethylsiloxane (PDMS) membranes were applied to the pervaporation of an azeotropic mixture containing trimethyl borate, a precursor to boronic acids used in Suzuki couplings and a gaseous anti‐oxidant in solder flux or brazing. The degree of cross‐linking of the chains in the active layer played a crucial role in the membrane process using the membranes PERVAP 4155‐80, PERVAP 4155‐40 and PERVAP 4155‐30. PERVAP 4155‐30 reached the best results from all tested membranes; an impressive selectivity with fast permeation was also achieved with the PERVAP 4060 membrane. Methanol preferentially passed through PERVAP 4155‐30, but trimethyl borate was favorably pervaporated from the mixture by PERVAP 6040, due to the diverse affinities of the membranes.     

A facile method for preparation of PGS@ZB‐N and gas‐sol alternating synergistic effect for fire resistance of EVA

Through the simple precipitation of palygorskite (PGS) by zinc borate (ZB) (to make PGS@ZB) and the decoration of PGS@ZB by dodecylamine (N), a novel organic‐inorganic@inorganic hybrid flame retardant of PGS@ZB‐N was prepared and was incorporated with ethylene vinyl acetate copolymer (EVA) to improve its flame retardance. The structure and morphology of PGS@ZB‐N were characterized by Fourier transform infrared (FTIR) spectroscopy, X‐ray diffraction (XRD), and scanning electron microscopy (SEM), and it was confirmed that the PGS@ZB‐N hybrid had been successfully prepared. The flame retardancy and burning behavior of EVA/PGS@ZB‐N/EG (EG = expandable graphite) composite were studied through thermogravimetric analysis (TGA), limiting oxygen index (LOI), UL‐94 (by the vertical burning test), and cone calorimeter test (CCT) characterizations. The prepared EVA/PGS@ZB‐N/EG composite obtained an LOI value of 41.2% with the addition of 30 wt% PGS@ZB‐N/EG. It was found that EVA/PGS@ZB‐N/EG was protected through a gas phase and condensed phase alternating synergistic effect mechanism.     

HPCS-AM-DAC共聚物的合成及絮凝性能研究

以羟丙基壳聚糖(HPCS)、丙烯酰胺(AM)、丙烯酰氧乙基三甲基氯化铵(DAC)为原料合成三元高分子共聚物(HPCS-AM-DAC)。采用FTIR、1HNMR、XRD、SEM对其结构和形貌进行了表征。考察了反应温度、引发剂硝酸铈铵用量、单体滴加时间及DAC用量对产物阳离子度及特性黏数的影响。结果表明,在水为25 mL、丙烯酰胺为2 g、HPCS为1 g、反应温度70℃、引发剂用量为1.7%(以HPCS质量为基准,下同)、单体滴加时间为35min、DAC为3.5g的条件下,产物的阳离子度和特性黏数均达到较佳值,分别为63.01%和468.81mL/g。采用壳聚糖(CTS)、HPCS、HPCS-AM-DAC及市售阳离子聚丙烯酰胺(CPAM)对高岭土模拟废水进行絮凝实验,考察了絮凝体系pH、不同絮凝产品投加量对浊度去除率的影响。结果表明,在浊度为200NTU的高岭土模拟废水中,HPCS-AM-DAC絮凝的适宜pH为2～6,适宜投加量为2～5 mg/L,在该条件下浊度去除率均在96%以上。     

分散剂Zr-201在橡胶中的应用研究

考察了新型硼酸酯分散剂Zr-201对天然橡胶胶料加工性能和胎面胶物理机械性能的影响。结果表明,Zr-201具有增塑作用,能降低NR混炼能耗和排胶温度,降低胶料的粘度,提高流动性;能改善NR的挤出特性,减小挤出口型膨胀,提高挤出物的表面光滑程度;Zr-201能提高N330炭黑在NR中的分散性;能缩短硫化时间和焦烧时间;Zr-201能明显提高胎面胶的撕裂强度,能提高硫化胶的拉伸强度、拉断伸长率和拉伸永久变形,降低定伸应力,硬度和耐老化性,对耐磨性影响不大。     

硼酸三甲酯-甲醇-氯化锂体系液液平衡的测定

分别采用Othmer法和液液平衡釜法测定了298.15K下硼酸三甲酯-甲醇-氯化锂三元体系的液液平衡数据。实验发现：氯化锂的摩尔分率对硼酸三甲酯在甲醇中的溶解度影响较大。在平衡的酯相和醇相中,当醇相中氯化锂的质量百分数小于12．99％时,醇相的密度小于酯相;当醇相中氯化锂的质量百分数大于14．24％时,醇相的密度大于酯相;酯相中硼酸三甲酯的质量百分数最高达98.8％,而氯化锂仅为0．01％。液液平衡的测定为氯化锂盐析工艺提供基础研究。     

硼酸铝晶须增强涂料的冲刷磨损性能研究

为了提高涂料的耐冲刷性能,采用在环氧酚醛涂料里添加分散好的硼酸铝晶须的方法,制备出一种晶须增强涂料。采用冲刷磨损试验机测试涂料的耐冲刷性能,结果表明,晶须增强涂料的冲刷磨损失重量明显小于环氧酚醛涂料,最合理配比为10%硼酸铝晶须+涂料,其冲刷磨损量为环氧酚醛涂料的1/3。晶须的钉扎连接作用消除了涂料固化的孔洞,提高了涂料的耐磨性能。     

锂离子电池电解质锂盐双草酸硼酸锂的研究进展

介绍了新型锂盐双草酸硼酸锂(LiBOB)的基本性质,归纳了其合成、检测和提纯方法,重点阐述了LiBOB在石墨类负极上的成膜性能,综述了LiBOB的溶解性和电导率、热稳定性及在固体电解质中的应用,总结了LiBOB基电解质的不足,指明了其未来的研究方向。     

乙撑双膦酸四甲酯的合成研究

以1,2-二溴乙烷、亚磷酸三甲酯为原料,合成阻燃剂乙撑双膦酸四甲酯,其最适宜的合成条件为二溴乙烷、亚磷酸三甲酯的摩尔比为1:3.5,在175℃下反应时8h,产品得率为7.15%,并用红外、核磁、元素分析等对产品进行表征。     

基于组装合成的(NH_4)_2[B_(10)O_(14)(OH)_4]·H_2O的结构及其合成机理的初步探讨

基于组装合成的思想,在水热条件下合成了一种水合铵硼酸盐.将孤立的硼氧聚阴离子通过聚合脱水自组装形成一维链状结构,链与链之间通过氢键作用形成硼酸盐层,铵离子和水分子填充在阴离子的骨架间隙中,并通过氢键将硼酸盐层连接起来.使用红外光谱、元素分析、热重-差热分析及X射线单晶衍射分析等手段,对该化合物结构进行了表征.单晶结构分析结果与假想结果相吻合,该化合物系孤立的五硼氧聚阴离子通过缩聚脱水形成一维无限链状结构,链与链之间通过氢键连接在一起,铵离子和水分子填充在骨架间隙当中.该化合物属三斜晶系,P-1空间群,晶胞参数a=0.76413(15) nm,b=0.92529(19) nm,c=1.1949(2) nm,α=99.49(3)°,β=105.87(3)°,γ=91.57(3)°.     

N,N-二羟乙基乙酰乙酰胺的合成及应用

二乙醇胺与乙酰乙酸甲酯反应合成了硼酸酯键合剂原料N,N-二羟乙基乙酰乙酰胺。通过均匀设计与SPSS软件处理实验数据,确定了N,N-二羟乙基乙酰乙酰胺收率与各反应因素的回归方程;最佳反应条件为:n(乙酰乙酸甲酯)/n(二乙醇胺)=1.3,催化剂w(ZnAc2.2H2O)=0.25%(以二乙醇胺的质量计,以下同),反应温度140℃,反应时间2.5 h,减压蒸除未反应原料得产物。在该条件下,N,N-二羟乙基乙酰乙酰胺收率达84.9%。以N,N-二羟乙基乙酰乙酰胺制备的硼酸酯键合剂BA-5-2在5 L高能丁羟四组元推进剂装药实验中的应用结果显示:推进剂常温、高温各项力学性能指标均高于发动机设计要求15%,高温黏附指数φ=1.037,其综合力学性能优于醇胺类键合剂LAB-303B、二乙醇胺硼酸酯键合剂BAG-5及海因三嗪类键合剂BA603。