优选投料量,降低淀粉消耗

我厂生产草酸,为了降低淀粉的消耗而达到优质高产的目的,经分析在反应母液量,温度及补加硝酸量等不变的条件下,主要影响因素是淀粉水解液投料量是否合适。投料过多,反应不完全,使消耗升高,投料太少,设备利用率又不高,因此要选择淀粉水解液的适当投料量。应用0.618法的原理,在165～205公斤范围内优选,做了三个点的试验(如下):     

冷法新型淀粉胶黏剂的制备

论述了新型淀粉胶黏剂的合成方法。以硫酸铜代替传统用硫酸亚铁作催化剂,选用草酸作胶黏剂脱色剂,采用冷法制备新型淀粉胶黏剂。结果表明：当催化剂硫酸铜用量为0.12%时,以黏度和初粘力为评价指标,通过正交试验确定了淀粉胶黏剂的最佳配方为：水77.9%,淀粉17.3%,双氧水0.28%,氢氧化钠1.3%,硼砂0.12%,单因素实验草酸添加量为2.9%时即可得到良好脱色效果,制备的胶液乳白色,扩大了产品适用范围。     

草酸催化对阿司匹林合成的影响

目的:探讨草酸作催化剂对阿司匹林合成的影响。方法:以水杨酸和乙酸酐为原料,探究草酸、温度、原料投料比等对收率的影响。结果:草酸催化下,控制温度在75℃,反应时间为60 min,水杨酸与乙酸酐的摩尔比为1︰3,水杨酸与草酸摩尔比为1︰4时收率最高(89.3%)。结论:相比浓硫酸催化,草酸催化合成阿司匹林的收率更高,更环保,具有一定的应用价值。     

微波辐射四氯化锡催化合成草酸二丁酯的研究

本文研究了以SnCl4为催化剂,以草酸和正丁醇为原料,在微波辐射下合成草酸二丁酯的方法.通过实验得出最佳反应条件为:醇酸摩尔比为3.5:1,催化剂用量为总投料量的2%,微波辐射功率为480W,在此条件下取得了较好的收率.     

葡萄糖废液制草酸

广州第四制药厂生产葡萄糖的废液含糖40%,PH 值为4,过去被用作制酱油,后因不符合食品卫生标准而停止使用。我厂试用此种废液代替淀粉生产草酸,先将液体烧碱与葡萄糖废液中和,使 PH 值达到8左右,然后进行浓缩,使其浓度达到60—70%,再用硝酸氧化,工艺设备与用淀粉生产草酸相同。以年产300吨草酸计,每年可节约粮食250多吨,降低成本七万元,做     

MF改性的淀粉胶黏剂的合成与性能研究

对玉米淀粉进行氧化、聚合处理,再使用MF改性,制得防水高黏型淀粉胶粘剂。同时采用正交实验法查验了淀粉糊化温度、NaClO相对于淀粉的质量比、PVA溶液质量分数和MF相对于淀粉的质量比对胶黏剂性能的影响。得到一款防水高黏型淀粉胶黏剂的制备条件为:PVA质量分数20%,淀粉糊化温度55℃,MF投料比1.25,NaClO投料比1%。在此条件下胶黏剂粘度达到GB/T 2794-1995的标准,耐水性能符合QB/T l094—1991的标准。     

对甲苯磺酸催化合成草酸二异戊酯的研究

以草酸和异戊醇为原料,对甲苯磺酸为催化剂,环己烷为带水剂,合成了新型柴油十六烷值改进剂草酸二异戊酯。考察了酸醇的物质的量比、反应时间、催化剂用量和带水剂用量等因素对酯收率的影响。结果表明:当反应温度为回流温度(85~100℃),n(草酸)∶n(异戊醇)=1∶3.5,催化剂用量为草酸质量的1.5%,带水剂用量为10mL/0.1 mol草酸,反应时间110~120 m in时,草酸二异戊酯的收率大于88%。与现有工艺相比,采用对甲苯磺酸为催化剂,环己烷为带水剂,具有反应温度低、反应时间短、带水剂的毒性较小、草酸二异戊酯的收率和纯度较高等优点。产物经红外光谱和气相色谱分析,证明确为草酸二异戊酯且纯度大于98%。     

开发以玉米为原料的草酸工业

本文介绍国内外草酸市场概况(?)述以玉米淀粉制草酸的工业技术以及开发玉米制草酸工业的广阔前景。     

草酸生产技术及进展

草酸学名乙二酸,是最简单的二元羧酸。1776年C.W.Scheele首先用硝酸氧化淀粉的方法合成出草酸。草酸通常以钾盐和钙盐的形式存在于各种植物的叶、根,和     

一种制备草酸的方法

本发明为用玉米杆为原料制备草酸的方法。玉米杆干燥粉碎后,在硫酸和母液(本法制取的析出草酸结晶后的母液)配制的酸液中进行水解,其水解温度按前后两期分别调控在308.15～313.15K和363.15～368.15K,水解液经氧化、结晶、精制得草酸。母液在水解中全部循环回用。草酸得率(以玉米杆投料的质量计)约为75％。玉米杆价廉易得,因此可大幅度降低草酸成本。     

淀粉氧化制草酸的新工艺研究

研究了用氧化法制备草酸中产生的富二氧化氮气尾气再次氧化淀粉制备草酸的工艺，找出了最佳工艺条件，草酸收率为５５％。     

硝酸氧化淀粉水解液制备草酸过程中NOx的回收利用

用淀粉水解液吸收硝酸氧化碳水化合物生产草酸过程中的ＮＯｘ，吸收率≥９９．２％。吸收过ＮＯｘ后的淀粉水解液进一步用硝酸氧化制备草酸时，可节约硝酸６７％，草酸收率也由原来的５６％提高到８０％以上。氧化条件温和，几乎无二次污染。     

橡子淀粉制取草酸的研究

介绍了硝酸氧化橡子淀粉制取草酸的方法，探讨了硝酸、硫酸用量对草酸产量的影响，为林产品在化工生产中的应用提供了一条新途径。     

硝酸氧化淀粉制备草酸动力学研究

探讨利用硝酸与淀粉在酸性及催化剂与助催化剂存在条件下合成草酸的反应机理,提出了在酸性条件下由淀粉水解成葡萄糖,葡萄糖进一步被硝酸氧化成草酸的宏观动力学模型。该过程分为2步:淀粉水解过程为表观一级反应,动力学方程为CA=CA0exp(-k1t);葡萄糖氧化过程通过稳态法处理后,动力学方程为CE=CB0(1-e-k2t)。通过实验计算出其中参数k1=0.082min-1;k2=0.0050min-1。研究结果为报废液体推进剂红烟硝酸的再利用提供了理论与技术支持。     

硝酸氧化法制草酸过程中各组分的分析检测

研究了硝酸氧化淀粉水解液制备草酸反应液中各组分的检测方法。采用旋光光度计检测葡萄糖含量,结果表明,葡萄糖在溶液中的质量比与溶液的旋光值呈良好的线性关系;采用高效液相色谱分析母液中的草酸含量。其余酸性组分采用碱溶液滴定。     

环保高效除锈膏的研究

研究了一种环保型高效除锈膏。分析了除锈膏的成分,给出了除锈膏的制备与除锈方法。除锈膏主要由10%磷酸、5%柠檬酸、2.5%草酸组成,其载体为明胶、黄土、淀粉,缓蚀剂为硫脲。实验结果表明,该除锈膏不产生刺激性气体,方便易用,可在不停产的条件下有效除锈,除锈后基体材料表面涂漆膜层的结合力良好。     

Graft polymerization of acrylic acid onto starch using potassium permanganate acid (redox system)

Graft polymerization of acrylic acid (AA) onto rice starch using postassium permanganate/acid redox system as initiator was investigated. When starch was reacted with KMnO₄ solution, MnO₂ was deposited onto starch. The dependence of MnO₂ amount deposited was directly related to KMnO₄ concentration. Subjecting the MnO₂-containing starch to a solution consisting of monomer (AA) and acid (citric, tartaric, oxalic and hydrochloric acid) formed poly(AA)–starch graft copolymers. The graft yield, expressed as meq COOH/100 g starch, was measured by the amount of MnO₂ deposited, AA concentration, material-to-liquor ratio, kind and concentration of acid, as well as temperature and duration. Finally, the newly prepared poly(AA)–starch graft copolymers were applied to cotton textiles to determine their suitability as sizing agents. The highest graft yield was obtained with citric acid and the least with hydrochloric acid, with tartaric and oxalic acid in between. The graft yield increased by increasing the concentration of acid to a certain concentration beyond which grafting leveled off. A similar trend was observed when the magnitude of grafting was related to the amount of MnO₂ deposited. The graft yield increased by increasing the polymerization temperature from 30° to 50°C. Increasing the temperature to 60°C is accompanied by decreased grafting. On the other hand, fabric samples sized with poly(AA)–starch graft copolymers acquire higher tensile strength, elongation at break, and abrasion resistance than that sized with native rice starch, i.e., poly(AA)–starch graft copolymers serve as good sizing agents for cotton textiles. A tentative mechanism for grafting rice starch with AA using the KMnO₄/acid redox system was elucidated. © 1995 John Wiley & Sons, Inc.     

Preparation and properties of starch oxalate half-ester with different degrees of substitution

Oxalic acid, a strong dicarbonic acid mainly come from starch, was used to esterify gelatinized corn starch under nonaqueous conditions to give a material with degrees of substitution (DS) ranging from 0.08 to 0.87 depending on the oxalic acid/starch molar ratios used. The reaction product was washed by extraction with 95% ethanol solution and then characterized by using spectroscopic techniques (FT-IR, ¹H-NMR and ¹³C-NMR). The results from these analyses revealed the presence of carbonylic groups, indicating that the esterification reaction was successful. SEM showed that granules of corn starch swelled on gelatinization and the particles had a porous structure favorable to esterification. The effect of different degree of substitution on properties of oxalate starch half-ester was studied by intrinsic viscosity measurement, wide angle X-ray scattering (WAXS), thermogravimetry (TG) and humidity absorption. X-ray diffraction studies revealed the loss of the ordered A-type crystalline structure, characteristic of corn starch. With the increase in DS, Mw (estimated by intrinsic viscosity), the thermal stability of starch oxalate half-ester decreased markedly while its ability to take up water increased due to the introduction of the carboxylic group.     

草酸改性凹凸棒土吸附偏二甲肼实验研究

通过草酸对凹凸棒土进行改性处理,以提高对偏二甲肼的吸附性能,分别考察了草酸浓度、固液比、分散剂、温度和活化时间对草酸处理后凹凸棒土吸附性能的影响,并通过正交实验对草酸改性凹凸棒土的最佳工艺进行了选择。结果表明:草酸为饱和溶液,固液比为1 g∶10 mL,分散剂质量分数为5%,温度为30℃,活化时间为60 min,上述工艺条件下,偏二甲肼吸附率可达95%。