膜粗酯蒸馏时游离酸含量控制指标探讨

在同分异构化生产合成樟脑的过程中,通过对膜粗酯蒸馏时游离酸含量与膜净酯、白乙酯的含量的变量关系研究,结果表明:膜粗酯蒸馏时游离酸含量的高低,决定了膜净酯,白乙酯中酯含量的高低。当膜粗酯蒸馏控制指标游离酸小于0.06％时,酯含量大于97％的白乙酯可达55％以上。     

C1—5醇乳酸酯及丙交酯制备的初步研究

用Ｃ１－５醇酯化Ｄ,－Ｌ乳酸制得相应的乳酸酯,其中用Ｃ４－５醇酯化乳酸不用带水剂,产率可达８０％以上,用Ｄ,Ｌ－乳酸酯制丙交酯会生成等量的外消旋与内消旋体。外消旋丙交酯为目标产物,内消旋丙交酯可回收作原料。由此计算外消旋丙交酯单程产率将不大于５０％,实验中除乳酸甲酯外,乳酸酯单程消耗和丙交酯单程产率分别为２６％－３５％和２２％－３５％。     

热稳性良好的和可生物降解的磺化脂肪-芳香共聚醚酯

这种磺化脂肪-芳香共聚醚酯包括：(A)摩尔分数为80％-20％(按A B计算)的芳香二羧酸或其酯，(B)20％-80％(按A B计算)的脂肪二羧酸或其酯，     

膜粗酯蒸饱时游离酸含量控制指标探讨

在同分异构化生产合成樟脑的过程中，通过对膜粗酯蒸饱时游离酸含量与膜净酯、白乙酯的含量的变量关系研究，结果表明：膜粗酯蒸馏时游离酸含量的高低，决定了膜净酯，白乙酯中酯含量的高低。当膜粗酯蒸馏控制指标游离酸小于０．０６％时，酯含量大于９７％的白乙酯可达５５％以上。     

α-糠硫醇及其羧酸酯的合成与香气特征

等摩尔α 糠醇与硫脲在１８％盐酸中于５０～６０℃反应,放置过夜后碱性水解４ｈ,得α 糠硫醇,收率为６０％。在００５ｍｏｌ４ 二甲氨基吡啶和０５５ｍｏｌ粉末状无水碳酸氢钠存在下,充分搅拌下０５ｍｏｌα 糠硫醇与０５ｍｏｌ酸酐在３００ｍｌ甲苯中回流脱水,分别合成了α 糠硫醇的乙酸酯、丙酸酯、丁酸酯、戊酸酯和己酸酯,各酯的收率依次为８８３％、９００％、８９０％、８６０％和８２０％。上述５个酯的香气特征为水果香型。     

碳酸二苯酯（DPC）合成新技术

华东理工大学化工学院在“2009全国有机碳酸酯技术开发与应用研讨会”上提出了新的碳酸二苯酯合成路线。新路线采用廉价的乙酸酐和苯酚反应生成醋酸苯酯,醋酸苯酯再和碳酸二甲酯进行酯交换反应生成碳酸二苯酯。在实验室小试研究中,合成路线醋酸苯酯的产率〉95％;醋酸苯酯和碳酸二甲酯反应中、碳酸二甲酯的转化率95％以上,碳酸二苯酯的收率95％以上;碳酸二苯酯的纯度99．5％以上,     

20％唑菌酯悬浮剂的配方及生物活性

[目的]对20％唑菌酯悬浮剂配方中的助剂体系进行筛选和优化,充分发挥唑菌酯对作物病害的防治潜力.[结果]获得的最优配方:唑菌酯20％,NNO 3％,JH 2％,0201B 2％,T-80 1％,黄原胶0.2％,白炭黑2％,乙二醇5％,消泡剂1522 0.5％,蒸馏水补足至100％.[结论]室内生物活性试验结果表明:20％唑菌酯SC对黄瓜炭疽病具有良好的防治效果,在质量浓度20 mg a.i./L防效可达92.59％,与原药相比生物活性得到了进一步提高.     

硅胶柱层析分析松香酸聚氧乙烯酯中单双酯及聚乙二醇含量

本文利用硅胶柱层析力方法，选择一系列极性递增的混合溶剂体系为梯度洗脱剂，对松香酸聚氧乙烯酯（ＰＯＲＥ）中单，双酯及聚乙二醇组分进行了定量分离与分析，分析结果表明松香酸聚氧乙烯酯中单酯含量７０－８０％，双酯１０～２０％聚乙二醇－１０％。     

相转移催化合成蔗糖油酸酯

以蔗糖和油酸酯为原料应用相转移催化剂(PTC)与碱性催化剂结合，合成蔗糖油酸酯，考察了反应时间、反应温度和催化剂用量对蔗糖油酸酯产率的影响，得出反应时间为4h，反应温度为100℃～110℃、催化剂聚乙二醇400(PEG-400)为油酸甲酯摩尔数的8％～10％，蔗糖油酸酯的产率达80％以上，单酯质量分数可以达到50％。     

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。     

Drying Kinetics of Instant Asian Noodles Processed in Superheated Steam

The objective for this work was to develop a novel technique for creating instant noodles by determining the drying kinetics of noodles undergoing simultaneous drying and processing using superheated steam. The mathematical model of moisture ratio was differentiated to determine the drying rates of noodles during processing. There was a constant rate drying period for all temperatures at a steam velocity of 1.5 m/s but there was no constant rate drying period at a steam velocity of 0.5 m/s. The constant rate drying period suggested by measurement of internal noodle temperature is much longer and well defined for all processing conditions than from the drying curves. The constant drying rate period, was nearly 200 s at 110°C but decreased to 50 s at 150°C. Equilibrium moisture content isobars were determined from mass changes during superheated steam processing. It was determined that isotherm equations for equilibrium moisture content in hot air systems may be utilized to model isobars in superheated steam systems.     

Improving Instant Rice Quality by Novel Combined Drying

The quality parameters of a new type of instant rice with higher moisture content and lower water activity (a _w) were investigated. The product was obtained after combining three types of drying processes as follows: air drying, microwave drying, and osmotic process. The new-type instant rice was evaluated by comparing it with freeze drying (FD), hot-air drying (AD), and freshly cooked rice. Several quality parameters were discussed, including color, texture, water molecule mobility, microstructure, flavor, and sensory. The comparison showed that the yellowness, hardness, and chewiness of the new-type instant rice had no significant difference with cooked rice, and it had better color and texture than FD and AD. Meanwhile, it showed much lower water molecule mobility and distinguished microstructure. In addition, the flavor and reconstituted sensory characteristic of the new instant rice were more similar to those of freshly cooked rice. In summary, the new instant rice ensured acceptable quality, and could be produced as a new form of instant rice.     

Optimum Processing Conditions of Instant Asian Noodles in Superheated Steam

There is little information in the literature about what constitutes an acceptable instant noodle. To ascertain the commercial acceptability of superheated steam-processed instant noodles, a sampling of commercial products was undertaken. Noodles processed at a steam velocity of 1.5 m/s and at 125°C for 200 s, 130°C for 167 s, 135°C for 150 s, 140°C for 133 s, 150°C for 100 s, and a steam velocity of 1.0 m/s and 150°C for 133 s had acceptable color values (L* values greater than 63, a* values less than 0, and b* values above 20) and moisture at or below the safe storage limit. Superheated steam processed noodles were more firm and chewy than the commercial noodles. Adhesiveness, springiness, and resilience were generally the same for all noodle products. Breaking strength of superheated steam processed noodles was in the same range as the fried control and commercial products. Values varied from a low of 1121 ± 194 g/mm² for noodles processed at 150°C, 1.5 m/s, for 100 s to a high of 1575 ± 329 g/mm² for noodles processed at 140°C, 1.5 m/s, for 133 s. Starch gelatinization was greatest in the fried control samples and the least in the superheated steam processed samples (approximately 9% less).     

Optimum Processing Conditions of Instant Asian Noodles in Superheated Steam

There is little information in the literature about what constitutes an acceptable instant noodle. To ascertain the commercial acceptability of superheated steam-processed instant noodles, a sampling of commercial products was undertaken. Noodles processed at a steam velocity of 1.5 m/s and at 125°C for 200 s, 130°C for 167 s, 135°C for 150 s, 140°C for 133 s, 150°C for 100 s, and a steam velocity of 1.0 m/s and 150°C for 133 s had acceptable color values (L? values greater than 63, a? values less than 0, and b? values above 20) and moisture at or below the safe storage limit. Superheated steam processed noodles were more firm and chewy than the commercial noodles. Adhesiveness, springiness, and resilience were generally the same for all noodle products. Breaking strength of superheated steam processed noodles was in the same range as the fried control and commercial products. Values varied from a low of 1121 ± 194 g/mm² for noodles processed at 150°C, 1.5 m/s, for 100 s to a high of 1575 ± 329 g/mm² for noodles processed at 140°C, 1.5 m/s, for 133 s. Starch gelatinization was greatest in the fried control samples and the least in the superheated steam processed samples (approximately 9% less).     

Effects of Superheated Steam Processing on the Textural and Physical Properties of Asian Noodles

Asian noodles were simultaneously cooked and dried in superheated steam at temperatures from 110 to 150°C and steam velocities of 0.5, 1.0, and 1.5 m/s. Textural and key physical properties of color, breaking stress, and starch gelatinization were measured to ascertain the effects of the superheated steam processing. Textural properties of adhesiveness, springiness, cohesiveness, chewiness, resilience, and hardness determined from a TPA were found to be generally unaffected by steam velocity. All properties but springiness increased with an increase in processing time. Increasing temperature decreased adhesiveness, springiness, cohesiveness, and resilience but increased hardness and chewiness to a small degree. Processing time greatly affected noodle color, resulting in browning at greater processing times. Results show that velocity was not a significant factor (p > 0.05) on the breaking strength of noodles. Temperature was only significant (p < 0.05) at 110 and 120°C and breaking stress decreased with increasing temperature. There were small decreases in breaking stress with processing time. Combined gelatinization of both amylopectin and amylose was an average of 80.5% for all superheated steam processed samples.     

溶胶-凝胶法制备RDX/SiO_2薄膜

为有效阻止RDX/SiO2膜的开裂,基于溶胶-凝胶法制膜原理,通过调节SiO2溶胶的摩尔配比和陈化时间,在其凝胶点处加入一定量RDX的N,N-二甲基酰胺(DMF)溶液,同时添加适量黏结剂,手工旋涂并冷冻干燥成膜。结果表明,适当增加水与正硅酸乙酯(TEOS)的摩尔比(r),缩短溶胶恒温陈化时间,缓慢干燥的同时保证环境湿度,加入质量分数3%~5%的氟橡胶(FPM2602)或聚乙烯醇(PVA),均可以增强凝胶骨架的连接作用,在一定程度上减少RDX/SiO2膜的开裂。     

Effect of polymer concentration on polarization switching in polysiloxane‐dispersed ferroelectric liquid crystals

Ferroelectric liquid crystal–polysiloxane composite films were prepared after dissolving them in diethyl ether as a solvent. The crosslinking was done by adding room temperature vulcanizer (mixture of tetra ethoxy silane and dibutyl tin dilaurate) as curing agent. These composite films show good electro‐optic properties with switching times on the order of few milliseconds. The preliminary results show that these systems can be useful as functional materials in electronic displays. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1209–1215, 2003     

A new process for dissolution of cellulose in ionic liquids

A new dissolving process (two‐step dissolving process), that is, cellulose was first swelled to the maximum in aqueous 1‐butyl‐3‐methylimidazolium chloride ([BMIM]Cl) solution, and then dissolved by stirring under vacuum to remove excessive water, was developed to prepare the cellulose/[BMIM]Cl spinning dope with high quality. The results showed that the initial water contents in [BMIM]Cl have great influence on the swelling and dissolution of cellulose, and the suitable swelling range of aqueous [BMIM]Cl solution, in which cellulose can be swollen but not dissolved, was 2–5% water content. In this range, the higher water content in aqueous [BMIM]Cl solution, the more swelling time would be taken for cellulose to reach the maximal swelling ratio. Based on these results, cellulose/[BMIM]Cl spinning dopes were prepared by using two‐step dissolving process. In the range of our experiments, cellulose spinning dopes prepared by the two‐step dissolving process had better properties, such as fewer particles, lower apparent viscosity, and higher uniformity, compared with the direct dissolving process. By using this new dissolving process, the spinning performance of cellulose/[BMIM]Cl dopes was improved, and the mechanical properties of regenerated cellulose fibers were better than those prepared by the direct dissolving process. Therefore, it is a good way to prepare cellulose/[BMIM]Cl spinning dopes by using the new dissolving process. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers     

碳酸钙渣中钙的溶出规律研究

通过配制不同摩尔比值的碳酸钙渣(碳酸钙的质量分数为87.29%)和硝酸进行反应,得到了钙的溶出规律,确定了硅和磷的溶出曲线,用MATLAB对数据作图,分别得到钙硅和钙磷的溶出差值三维图形。结果表明,在保证钙的较大溶出率条件下,碳酸钙渣和硝酸的最佳摩尔比为1∶1.8,从而为钙渣中活性钙的溶出工艺过程提供了参考标准。     

马尾松预水解硫酸盐法制人造纤维浆粕工艺的研究

对马尾松制人造纤维浆粕过程中的预水解工艺进行研究,比较了不同液比、最高温度及保温时间的处理效果。研究结果表明:预水解最佳工艺条件为液比1:6;最高温度170℃;保温时间90min。蒸煮工艺采用常规硫酸盐法蒸煮,漂白采用全无氯(TCF)漂白。在此条件下,可获得性能优良的浆粕。