甲基有机硅树脂的无溶剂合成研究

以甲基三乙氧基硅烷单体和二甲基二乙氧基硅烷单体为原料,采用水解-缩聚的方法合成了甲基有机硅树脂,并研究了无溶剂合成甲基有机硅树脂的条件。结果表明,一定配比,水解温度为70℃,缩聚温度为80～85℃,反应时间为4h,可合成无溶剂体系的甲基有机硅树脂;红外光谱(IR)表明,合成的甲基有机硅树脂在Si-O-Si处有较宽的吸收峰;固化温度为140℃,固化4h,得到无色透明甲基有机硅树脂。     

Solvent-free enzymatic synthesis of structured lipids from peanut oil and caprylic acid in a stirred tank batch reactor

Structured lipids were synthesized by transesterification of peanut oil and caprylic acid in a stirred-batch reactor. Different substrate molar ratios (1:1 to 1:4, peanut oil/caprylic acid) were used. The reaction was performed for 72 h at 50°C catalyzed by IM60 lipase from Rhizomucor miehei (10 g, 2% w/w substrate) in the absence of organic solvent. The highest incorporation of caprylic acid was obtained with a 1:2 molar ratio (peanut oil/caprylic acid) after 72 h reaction. With a 1:2 molar ratio, the incorporation increased by 28% from 1:1. On the other hand, a 1:4 molar ratio gave the lowest incorporation during the reaction. The effect of different mixing speeds (200, 640, or 750 rpm) on reaction was studied with a 1:2 substrate molar ratio for 24 h. A high incorporation of caprylic acid (14.3 mol%) was obtained at 640 rpm, while 200 rpm gave the lowest incorporation (2.2 mol%), suggesting that good mixing is essential in a stirred-batch reactor. After 24 h of reaction at different rpm, IM60 lipase was recovered, washed with hexane, and reacted with substrates to study its stability after reaction at different mixing speeds. The results showed that caprylic acid incorporation was similar (24.9, 24.3, 24.2 mol%) at 200, 640, and 750 rpm, respectively. When 20 g of IM60 lipase (4% w/w substrate) instead of 10 g was used in a 1:1 substrate molar ratio reaction, the incorporation of caprylic acid increased by 26% after 72 h. To study enzyme reuse, 10 g of IM60 lipase was used in a 1:1 substrate molar ratio for 24 h at 640 rpm. The incorporation of caprylic acid gradually decreased with increased number of reuses. During five times of reuse, 15, 13.9, 9.6, 6.7, and 9.7 mol% of caprylic acid were incorporated into peanut oil, respectively.     

混合多元醇对无溶剂聚氨酯覆膜胶性能的影响

以聚己二酸-1,4-丁二醇酯(PBA)、植物油多元醇、异弗尔酮二异氰酸酯(IPDI)和小分子多元醇为主要原料,制备了一种双组分无溶剂型聚氨酯胶粘剂。研究了双组分的配比R′和混合多元醇组分对聚氨酯胶粘剂固化速率、固化后胶膜的热稳定性和吸水率的影响,并测试了覆膜样品的T剥离强度。结果表明:当双组分配比R′=1.3时,胶粘剂综合性能最佳;添加小分子多元醇并不能提高胶粘剂的固化速率和耐热性,但能显著改善胶粘剂的粘结性能,并且选择性添加适量的小分子二醇,还能增强其耐水性。     

Expression and characterization of a CALB-type lipase from Sporisorium reilianum SRZ2 and its potential in short-chain flavor ester synthesis

A lipase from Sporisorium reilianum SRZ2 (SRL) with 73% amino acid sequence identity to Candida antarctica lipase B (CALB) was cloned and overexpressed in Pichia pastoris. The recombinant SRL showed a preference for short-chain p-nitrophenyl esters. It achieved maximum activity at pH 8.0 and 65°C for p-nitrophenyl hexanoate (C6) with K_m and k_cat/K_m values of 0.14 mmol∙L⁻¹ and 1712 min⁻¹∙mmol∙L₋₁ at 30°C, respectively. SRL displayed excellent thermostability and pH stability, retaining more than 79% of its initial activity after incubation at 60°C for 72 h and 75% at pH 3 to 11 for 72 h. It also maintained most of its activity in the presence of inhibitors and detergents except sodium dodecyl sulfate, and it tolerated organic solvents. SRL was covalently immobilized and successfully used for ethyl hexanoate synthesis in cyclohexane or in a solvent-free system with a high conversion yield (>95%). Furthermore, high conversion yield was also achieved for the synthesis of various short-chain flavor esters when high substrate concentrations of 2 mol∙L⁻¹ were applied. This study indicated that a CALB-type lipase from S. reilianum SRZ2 showed great potential in organic ester synthesis.     

功能化Bronsted-Lewis酸性离子液体催化合成1-氨基烷基-2-萘酚

本文合成了Bronsted-Lewis酸性咪唑离子液体[CH2COOHmim]FeCl3Br,并研究了该离子液体作为催化剂,将2-萘酚、芳香醛、酰胺三组分在无溶剂条件下于100 ℃合成一系列的1-氨基烷基-2-萘酚。产物用IR、1HNMR、13CNMR对其结构进行确认。实验结果表明该方法环境友好,操作简单,产率较高,催化剂离子液体可多次循环使用。     

无溶剂条件下氧化锌催化合成肉桂腈

以ZnO为催化剂,在无溶剂条件下,肉桂醛和盐酸羟胺通过一步法合成了肉桂腈。ZnO催化合成肉桂腈的适宜反应条件为:n(肉桂醛)∶n(盐酸羟胺)=1∶1.5,催化剂用量为肉桂醛质量的6%,反应温度120℃,反应时间1 h,肉桂腈的收率可达90.2%。ZnO商业上容易得到,是一种环境友好催化剂。     

无溶剂环氧防腐涂料的制备和性能研究

开发了一种以腰果酚改性胺为固化剂的无溶剂环氧防腐涂料,介绍了环氧树脂、固化剂、稀释剂以及填料等原料的选择,探讨了环氧树脂与腰果酚改性胺的固化机理,并考察了硅烷偶联剂对涂层防腐性能的影响。检测结果表明,环氧树脂与腰果酚改性胺的固化主要以环氧基与胺基之间的反应为主;硅烷偶联剂可以提高涂层的附着力,有效地增强涂膜的耐水性。     

无溶剂环氧玻璃鳞片涂料的研制

EP-9402无溶剂环氧玻璃鳞片涂料是一种由苯基缩水甘油醚、环氧树脂同混合固化剂反应的高分子网状结构为主要成膜物的双组分常温固化涂料,该涂料通过添加经偶合处理的一定粒径的片状鳞片实现涂层优异的耐化学介质性和附着性,涂料无挥发性溶剂、气味小,安全环保。本文介绍了该涂料的配方研制和制造过程、性能指标以及现场应用情况。     

KF催化无溶剂合成香豆素-3-甲酸乙酯

以水杨醛和丙二酸二乙酯为原料,分别选用4种无机盐代替六氢吡啶作催化剂,催化合成香豆素-3-甲酸乙酯.结果表明,KF· 2H2O与无水K2CO3具有明显的催化活性.通过设计正交试验考察了反应物摩尔比、催化剂KF·2H2O用量、反应时间等因素对反应产率的影响,获得优化工艺条件为:水杨醛用量5.0 g(4.2 mL,0.041 mol),水杨醛与丙二酸二乙酯摩尔比1∶1.2,KF·2H2O用量0.46g,无溶剂条件下加热蒸馏反应约45 min,平均产率可选89.71％.     

无溶剂SiO2纳米流体的制备及其导电性能研究

本文中首先以SiO2纳米粒子为核,通过脱水反应在SiO2纳米粒子表面接枝3-硅羟基-1-丙基磺酸(SIT),再通过一元弱碱解离反应,以离子键接枝反离子聚氧乙烯十八烷基胺(Ethomeen18/25),所形成的有机/无机杂化纳米材料在室温下呈金黄色的透明液体状,称其为无溶剂纳米流体.单分散态无溶剂SiO2纳米流体中,Si...