聚氨酯胶粘剂水解问题的有效解决途径

聚合物有几种主要的降解机理:热降解、化学物降解、氧化降解、微生物降解以及水解降解。其中,水解是缩聚反应生成的聚合物最致命的弱点,聚氨酯粘合剂也不例外。水解使聚合物的力学性能在一段时间后丧失殆尽,严重影响了其使用性能和应用范围。碳化二亚胺(Stabaxol~(?))是为解决酯类聚合物水解问题而研制的高效抗水解剂。文章描述了碳化二亚胺抗水解剂在聚酯型聚氨酯粘合剂中的水解保护机理及效果。     

盐酸美金刚胺的合成及表征

通过比较不同的反应路线，确定了以1，3-二甲基金刚烷为原料，经溴代、乙酰氨基化、水解反应最后经酸化得到盐酸美金刚胺。改进并优化了合成路线，溴代反应确定为在回流条件下反应12h，n（1，3-二甲基金刚烷）：n（溴素）=1：1．5；水解反应条件是以，7（乙二醇）：n（水）=10：1为溶剂，150℃下反应12h，n（1-乙酰氨基-3，5-二甲基金刚烷）：n（氢氧化钠）=1：5，反应总收率达81．5％。产品用IR、ESI、^1HNMR、^13CNMR确证了产品的结构。     

Water activity-adjusted enzymatic partial hydrolysis of phospholipids to concentrate polyunsaturated fatty acids

Selective partial hydrolyses of egg yolk phospholipid and squid skin phospholipid were carried out. By keeping the water activity (a _w) of Lipozyme IM at an intermediate level, it was easy to concentrate docosahexaenoic acid (DHA). It was also possible to concentrate both DHA and arachidonic acid (AA) simultaneously to a certain level under this a _w range. However, it was impossible to concentrate AA alone when DHA was present. Though there is a limitation in concentrating AA exclusively, the proposed a _w-adjusted hydrolytic reaction is a promising way for preparing phospholipids rich in DHA.     

硝酸酸解方铅矿生产铅产品的湿法开发研究

应用硝酸酸解方铅矿生产多种铅产品 ,主要从工艺原理、溶矿方法、反应操作条件和“三废”处理等方面综合介绍了以硝酸为溶剂湿法开发方铅矿的研究结果。其中硝酸酸解方铅矿的工艺条件为 :温度 65～ 90℃ ,pH为 0～ 1.5。     

聚氨酯的化学降解

介绍了聚氨酯（PU）的水解、热降解、热氧化降解和紫外线降解的反应机理。PU的水解主要发生在酯基上，PU的热降解通常在氨基甲酸酯基上产生，PU的热氧化降解作用于醚基上，PU的紫外线降解在氨基甲酸酯基上断裂。芳香二异氰酸酯合成的PU在紫外线照射下，生成酯式结构，导致PU变黄。同时还指出了添加稳定剂可改善聚氨酯的稳定性。     

Effect of the preparation condition on the properties of titania-silica derived from tetraisopropyl titanate(IV) and tetraethyl orthosilicate

Titania-silica mixed oxide was prepared by hydrolyzing tetraethyl orthosilicate and tetraisopropyl titanate(IV) with a mixture of ethanol and 0.01 N aqueous acetic acid. Surface Ti content, BET surface area, and the number of acid sites increased with an increase in 0.01 N aqueous acetic acid. Thus hydrolysis of both alkoxides occurred simultaneously with a large amount of the acetic acid solution, and there was extensive interaction between TiO₂ and SiO₂ phases. With small amount of 0.01 N aqueous acetic acid, however, titanium hydroxide was first formed and, then, it was covered with the silica phase produced in a later stage of the hydrolysis. Increase in the acetic acid solution also led to the formation of a large amount of tetrahedral Ti species, which were active for the epoxidation of oct-1-ene usingt-butyl hydroperoxide as an oxidant.     

塔拉单宁酸制取3,4,5-三甲氧基苯甲酸甲酯的研究

利用塔拉单宁酸原料制备3，4，5－三甲氧基苯甲酸甲酯并应用于工业生产，研究选择了最佳工艺条件，3，4，5－三甲氧基苯甲酸甲酯的产率按塔拉单宁酸投料量计达92．11％，塔拉单耗为2．03t/t .     

An enzymatic approach to the determination of the degree of stabilization of organic carbon in fertilizers

An enzymatic approach to assess the stability of organic matter extracted from organic fertilizers and amendments is proposed. The use of 0.1M NaOH plus 0.1M Na₄P₂O₇ previously suggested as a suitable extractant solution for soil organic matter was also found satisfactory for the extraction of organic matter from organic fertilizers and amendments, especially when the temperature was raised to 65°C. The presence of nonhumified compounds in the extracts from organic fertilizers may interfere considerably during fractionation of organic carbon. An enzymatic hydrolysis with lipase, lysozyme and pronase, added sequentially to the extracts, led to an appreciable reduction in the interference. The interference was further reduced by carrying out a successive acid hydrolysis with 3N H₂SO₄; in this case the DH values (percentage of humified fractions with respect to total extractable carbon) were reduced to less than 10% in all organic fertilizers, but remained higher than about 70% in organic amendments.     

Combined FTIR,reactivity and quantum chemistry investigation of COS hydrolysis at metal oxide surfaces used to compare hydroxyl group basicity

Three distinct approaches were used in the present work to investigate COS hydrolysis at metal oxide surfaces: (i) in situ FTIR spectroscopy, to provide information on the type of reaction intermediate species formed; (ii) reactivity measurements; (iii) quantum chemical calculations using ab initio Slater type orbital wavefunctions (STOP package) for COS and the semi-empirical GEOMOS-GREEN package, to give transition state structures and activation energy barrier heights. These three methods were found to be in excellent agreement. In particular, it is confirmed by FTIR and quantum chemical calculations that the COS hydrolysis mechanisms on Al₂O₃, TiO₂ and ZrO₂ are all of the type already published for the Al₂O₃ type I surface hydroxyl case. The relative activity hierarchy of these catalysts towards COS hydrolysis per unit area is: ZrO₂Al₂O₃ >TiO₂. This agrees with the amount of CO₂ adsorbed in the form of hydrogen carbonate species measured by FTIR spectroscopy and the calculated barrier heights, more product-like C-O distance in the transition state and carbonyl charge. ZnO was investigated by FTIR spectroscopy and using GEOMOS. Both approaches indicate the formation of the monothiocarbonate adduct instead of hydrogen thiocarbonate species which explains the complete inactivity of ZnO for COS hydrolysis.     

纤维素酶的研究及其在饲料中的应用开发

纤维素酶具有高效性和安全性,是当前开发非常规饲料及提高现有常规饲料资源利用率和提高畜禽生产性能的重要途径之一。中国食品发酵工业研究所开发了固态发酵法生产纤维素酶的工业化技术,发酵酶活力达到1400u/g,并解决了杂菌污染问题,可大大减轻劳动强度。通过饲养实验发现,纤维素复合酶制剂比单一制剂效果好,饲料中合适的添加量为0.1％~0.2％。目前这类酶制剂正获得普遍的推广和应用。