共查询到19条相似文献,搜索用时 109 毫秒
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以甲醛、异丁醛和季戊四醇为主要原料,在催化剂作用下利用循环一锅法合成螺二醇。通过正交优化实验,考察了物料配比、温度、反应时间、溶剂量以及催化剂对两步法合成螺二醇收率的影响,确定了合成螺二醇最佳工艺条件,在该适宜条件下,开发了循环-锅法的制备工艺,即n(甲醛):n(异丁醛):n(季戊四醇)=2.85:2.85:1,反应温度75℃,反应时间9h,产品总收率和纯度可达95.4%和99.9%。采用。HNMR和HPLC确定了螺二醇产品结构和纯度。 相似文献
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醇钠法合成一缩二丙二醇的工艺过程控制 总被引:1,自引:0,他引:1
介绍了一缩二丙二醇的用途及合成方法,重点阐述了以乙醇钠为催化剂,用丙二醇和环氧丙烷在一定温度和压力条件下合成一缩二丙二醇的反应原理和工艺流程,从反应温度、压力、精馏方式、催化剂回收等方面对生产工艺过程控制进行了探讨,总结出一种效率高,成本低,质量好的一缩二丙二醇的生产工艺条件。 相似文献
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枸橼酸焦磷酸铁配合物,能够作为依赖血液透析的慢性肾病患者提高血红蛋白和血清铁水平的铁剂替代产品。本文介绍了一种一锅煮法制备枸橼酸焦糖磷酸铁。此方法操作简便、条件温和且产率较高,是合成苯基苄基缩氨基硫脲的一种简便实用的方法,且能保证配合物的含铁量。 相似文献
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氟化锂是一种重要的无机氟化物,在诸多领域有着广泛的应用。高纯氟化锂的合成可分为直接合成法、离子交换法和溶剂萃取法,直接合成法又分为干法和湿法。详细介绍了各种方法的工艺,与湿法相比较,干法具有工艺简单、投资低、适于连续化生产等优点。采用溶剂萃取法可使氟化锂产品中的过渡金属质量分数降至10-9级,特别适用于制造光学纤维和锂离子二次电池的电解质。 相似文献
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通过气流破碎优化经碳化-离子交换-热解辅以高温干燥工艺制备的高纯碳酸锂粉体材料的粒径分布,研究发现气流破碎系统的喂料阀频率、分级轮和引风机频率变化对物料的粒径分布有重要影响。对4种不同粒度的样品共计18组实验分析各因素对物料粒径的影响,当设置喂料阀频率25~28Hz、分级轮频率30~35Hz、引风机频率35~40Hz时破碎效果最佳,该工作参数对于样品初始粒径在5μm≤d10≤14μm、20μm≤d50≤50μm、70μm≤d50≤110μm范围的碳酸锂颗粒粒径优化控制具有普适性。合理的气流破碎参数设置不仅使高纯碳酸锂物料具有良好的分散性和较规则的形貌,而且经等离子耦合激光光谱仪(ICP)检测证明气流破碎后不会引起高纯碳酸锂磁性异物和杂质含量的增加。这一研究对优化粉体材料形貌、实现特定粒度材料制备具有一定意义。 相似文献
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尖晶石粒度对高纯刚玉-尖晶石浇注料性能的影响 总被引:7,自引:1,他引:7
研究了尖晶石粒度对高纯刚玉 -尖晶石浇注料的抗折强度、抗热震性、抗侵蚀性等性能的影响。实验表明 :(1)随着配料中尖晶石颗粒含量的增加 ,试样的烧后强度呈先升高后降低趋势 (烘后强度变化不明显 ) ,烧后收缩减少 ,然后变为膨胀 ;(2 )尖晶石细粉与颗粒为 1:3的试样抗热震性较好 ;(3)对于高碱度渣 ,尖晶石颗粒加入量较多的试样抗侵蚀性较好 ;(4)对于低碱度渣 ,尖晶石细粉加入量较多的试样抗侵蚀性和抗渗透性均较好。 相似文献
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Gunasunderi Raju Mahmoud M. Shaban Reem K. Farag Thiruventhan Karunakaran Mohammad Khalid 《应用聚合物科学杂志》2023,140(2):e53286
The present work highlights the preparation of the epoxidized natural rubber conjugated spent coffee biocomposites (ENR-g-SC) via one-pot synthesis to control petroleum oil spills. The structural determination of the spent coffee grafted epoxidized natural rubber (ENR-g-SC) was confirmed through FTIR and 1H-NMR spectroscopic analyses. The thermal performance, tensile tests, and morphological properties of the synthesized (ENR-g-SC) biocomposites were performed. The data revealed that ENR-g-SC biocomposite with 20 phr of spent coffee (SC) exhibited the highest tensile properties due to maximal chemical linkages of spent coffee and epoxide groups in ENR. The epoxidized natural rubber conjugated spent coffee copolymers were evaluated as oil sorbers for oil absorbency applications in chloroform, toluene, and 10% crude petroleum diluted with toluene. The data revealed that the oil absorbency increased slightly with chloroform or toluene instead of 10% crude oil diluted with toluene. Furthermore, swelling and network parameters including the maximum oil absorbency (Qmax), swelling rate constant (k), polymer-solvent interaction (χ), effective crosslink density (ύe), equilibrium modulus of elasticity (GT), and average molecular weight between crosslinks (Mc) and theoretical crosslink density (ύt) were determined, and correlated to the efficiency of the synthesized epoxidized natural rubber conjugated spent coffee. 相似文献
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针对目前氟吡菌酰胺中间体(2-[3-氯-5-(三氟甲基)吡啶-2-基]乙胺(5))合成路线长、操作复杂,产品收率低、工业生产成本高等问题,本文系统开展了(5)绿色合成工艺的研发。以2,3-二氯-5-(三氟甲基)吡啶(1)为原料,选择将亲核取代、脱羧两步反应合为一锅法制得2-[3-氯-5-(三氟甲基)吡啶-2-基]乙腈(3),之后将催化加氢还原和水解连续进行得到氟吡菌酰胺中间体(5)的盐酸盐。在一锅法中详细考察了溶剂、碱、pH等重要因素对收率的影响。优选溶剂为DMF、碱为无水碳酸钾、pH为0.5~1,产品(3)收率达到88.1%,纯度98.5%。在加氢还原和水解连续反应中探索了催化剂种类、加氢反应时间和温度以及水解中盐酸用量等影响。结果表明,采用5% Pd/C催化剂(型号R5K1),在加氢反应温度15℃、反应时间12h、水解时38%浓盐酸用量为n(HCl)∶n(3)=5.5,产品(5)收率达78.8%,纯度为96.2%。同时,实现了工艺中各步溶剂以及Pd/C催化剂的高效回收套用,为该中间体的清洁工业生产提供了新技术支撑。 相似文献
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Alireza Samzadeh-Kermani 《Journal of Sulfur Chemistry》2016,37(1):105-113
A simple and efficient route for the synthesis of 1,3-oxathiolanes containing highly polarized C–C double bonds is reported. Anionic adduct derived from nitromethane and carbon disulfide attacks on oxiranes regioselectively using Et3N under microwave irradiation. This protocol has the advantages of short reaction time, solvent-free conditions, and easy workup procedure. 相似文献
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Inês de F.A. Mariz 《Polymer》2010,51(18):4044-372
A polymerization process to synthesize bimodal latexes with maximum particle diameters below 350 nm and solids content above 65 wt% has been developed.The process is based on an iterative strategy to determine the optimal particle size distribution that gives the maximum packing factor for a given range of particle sizes and at a given solids content. The calculated optimal bimodal PSD was experimentally obtained in a seeded semi-continuous emulsion polymerization reaction as follows: in the first step, a polymer seed latex was loaded in the reactor and grown, under monomer starved conditions, until a given particle size. At this point a fraction of the same seed was added to the reactor and the feed was continued until the desired particle size distribution and solids content were achieved. The point at which the seed was added again to the reactor and the amount of seed required were determined by the iterative strategy and depended on the competitive growth rate ratio of large and small particles that is an input for the iterative strategy.Implementation of the solution obtained from the iterative strategy, and for the first time in the open literature, led to the production of a coagulum free and stable bimodal latex with 70 wt% of solids content and particle sizes below 350 nm. 相似文献