单氰胺

单氰胺容易水解生成尿素或聚合生成双氰胺,很难生产、贮存、运输。目前的工业化路线是以氰胺化钙、CO2、水为原料。国外生产企业为德国的德固萨公司、日本电石工业株式会社和挪威Odd公司。国内宁夏大荣实业集团有限公司于2001年建成了年产3000t单氰胺的工业化生产装置,产品质量达到国外产品水平。估计单氰胺的需求量会以每年4％～6％的速度递增。     

双氰胺生产的节能改造与过程优化

随着双氰胺产品市场竞争加剧和生产原料成本逐年上升,以及国家地方等环保部门对环境保护严格要求,公司目前双氰胺生产工艺已越来越不能满足市场和环保需要。因此必须对双氰胺生产工艺进行节能改造,以提高资源利用率;对生产过程进行过程优化,提高产品质量,满足市场需求。     

Dicyandiamide analysis and solubility in epoxy resins

A simple procedure is described for the rapid, quantitative analysis of dicyandiamide in epoxy resins and epoxy resin prepregs. High performance liquid chromatography is used to analyze for dicyandiamide and to investigate the solubility behavior of dicyandiamide and 3-(p-chlorophenyl)-1,1-dimethylurea (Monuron) in liquid epoxy resins. Solubility expressions and differential heats of solution are determined. The formation of soluble amine-epoxy reaction products and epoxy resin additives such as Monuron are found to enhance the solubility of dicyandiamide.     

盐酸二甲双胍中双氰胺检测方法的改进

采用薄层色谱法，以８５％乙醇为溶媒，以氯仿－甲醇－水（１６：１０：５）为流动相，以硅胶Ｇ为固定相，测定了盐酸二甲双胍中双氰胺，结果与部标方法一致。本法与部标方法比较，具有简便、快速、灵敏、所用试剂毒性小等特点。     

两步法合成双氰胺

本文介绍了采用两步法由石灰氮合成双氰胺的生产工艺，并从浓度、温度、压力、反应时间、酸碱度、生产成本等角度探讨最佳参数，获得符合国家专业标准的双氰胺白色晶体。     

Network Polymers Based on Epoxy Oligomers and Dicyandiamide

The formation of network polymers by curing epoxy oligomers with dicyandiamide was investigated. The oligomers had the structure It was shown that the reaction between hydroxyl and epoxy groups is important in this process. The strength-deformation properties of the network polymers obtained were studied. Calculations of elastic active network chains were carried out by the method of branching processes. Good agreement was obtained between calculated and experimental data.     

单氰胺集装箱冒烟泄露事故分析及防范措施

对近期发生在深圳某港口的两起集装箱化学品泄露事故做了现场调查取证,以箱内货物单氰胺的物理、化学性质为依据,结合集装箱存放的环境条件,分析了该事件发生的原因,评估了其影响程度。并提出了处理方法及防范措施,期望可作为将来类似工作的指导和参照。     

对甲基苯胺改性双氰胺环氧固化剂的合成及性能

用对甲基苯胺对双氰胺进行改性,制备了一种新型的改性双氰胺固化剂,对合成条件进行了优化,并对其固化环氧树脂条件进行了研究。结果表明,对甲基苯胺改性双氰胺的较佳工艺条件为对甲苯胺和水的物质的量比定为1∶1.5,双氰胺和苯胺的物质的量比为1∶1,转速为一档,于90℃,反应3h,收率85%。通过测试涂层硬度来考察固化工艺与性能。作为环氧树脂固化剂单独使用时,固化温度为110℃,比双氰胺体系固化温度160℃降低了近50℃,对甲基苯胺改性双氰胺固化温度高于120℃时,涂膜硬度大于双氰胺固化温度为160℃时涂膜硬度。     

邻氨基苯甲酸改性双氰胺的制备与表征研究

以邻氨基苯甲酸为基本原料,合成了一种新型的双氰胺衍生物--邻双胍基苯甲酸盐酸盐,讨论了反应条件对合成的影响,并通过熔点、FT-IR、1H-NMR和UV表征了产物结构.结果表明,邻双胍基苯甲酸盐酸盐适宜的合成条件为:邻氨基苯甲酸对双氰胺的物质的量比为1.5、盐酸与邻氨基苯甲酸的物质的量之比为0.6、反应温度为60℃、反应...     

Interaction of Epoxy/Dicyandiamide Adhesives with Metal Substrates

The molecular structure of the interphase formed by curing a model adhesive system consisting of the diglycidyl ether of bisphenol-A (DGEBA) and dicyandiamide (DDA) against mechanically polished aluminum and electrogalvanized steel (EGS) substrates was determined using reflection–absorption infrared spectroscopy (RAIR) and X-ray photoelectron spectroscopy (XPS). RAIR analysis suggested that DGEBA/DDA mixtures created an interphase with a different molecular structure from the bulk of the adhesive when cured in contact with aluminum. The formation of this unique interphase was mainly due to interactions between DDA and the Al surface. XPS analysis indicated that aluminum ions exposed by heating the substrate surface were necessary for this interaction. DDA was found to adsorb onto the aluminum surface via the lone pair of electrons on the nitrogen atoms of the nitrile groups. A slight decrease in the nitrile stretching frequency suggested an additional back-bonding interaction between aluminum ions and the nitrile groups. Slight back donation of electrons from the metal to DDA resulted in a reduction product that led to the formation of the carbodiimide form of DDA. This specific reaction caused a decrease in the concentration of nitrile groups in the interphase and changed the extent of the reaction between DDA and DGEBA by inhibiting the formation of oxazolidine structures. The interaction of DDA with EGS surfaces followed a similar trend. However, the effects were much more pronounced with EGS and the extent of the curing reaction and the cross-linking rate near the metal surface were strongly affected by EGS/DDA interactions.     

双氰胺改性偶氮二甲酰胺在聚丙烯中的发泡特性研究

以偶氮二甲酰胺（AC）为参照,通过TG、DSC、动态粘弹性分析和发泡体系熔体回弹高度差测试,研究双氰胺改性AC发泡剂的分解温度,放热量及其在各种聚丙烯基体中的发泡特性。     

Interaction of Epoxy/Dicyandiamide Adhesives with Metal Substrates

The molecular structure of the interphase formed by curing a model adhesive system consisting of the diglycidyl ether of bisphenol-A (DGEBA) and dicyandiamide (DDA) against mechanically polished aluminum and electrogalvanized steel (EGS) substrates was determined using reflection-absorption infrared spectroscopy (RAIR) and X-ray photoelectron spectroscopy (XPS). RAIR analysis suggested that DGEBA/DDA mixtures created an interphase with a different molecular structure from the bulk of the adhesive when cured in contact with aluminum. The formation of this unique interphase was mainly due to interactions between DDA and the Al surface. XPS analysis indicated that aluminum ions exposed by heating the substrate surface were necessary for this interaction. DDA was found to adsorb onto the aluminum surface via the lone pair of electrons on the nitrogen atoms of the nitrile groups. A slight decrease in the nitrile stretching frequency suggested an additional back-bonding interaction between aluminum ions and the nitrile groups. Slight back donation of electrons from the metal to DDA resulted in a reduction product that led to the formation of the carbodiimide form of DDA. This specific reaction caused a decrease in the concentration of nitrile groups in the interphase and changed the extent of the reaction between DDA and DGEBA by inhibiting the formation of oxazolidine structures. The interaction of DDA with EGS surfaces followed a similar trend. However, the effects were much more pronounced with EGS and the extent of the curing reaction and the cross-linking rate near the metal surface were strongly affected by EGS/DDA interactions.     

双氰胺渣中有害成份的究研及处理

我国工业废渣中有电石渣,废石灰渣, 双氰胺渣及煤渣等.尤其双氰胺渣的堆积不仅占用土地.其有害成份氰的存在严重污染生存环境,给人们的生存条件带来了极大的危害文章对双氰胺渣作了一些研究分析,并针对其性质给出了合理的处理方法.     

咪唑促进双氰胺固化环氧树脂体系固化动力学

采用差示扫描量热(DSC)法研究了2-乙基-4-甲基咪唑(2E4MI)的含量对双氰胺(DICY)固化环氧树脂体系固化动力学的影响。非等温DSC测试结果表明,2E4MI能大幅度降低DICY固化环氧树脂所需要的温度和活化能,从而加快反应的进行。当2E4MI用量为0.2份时,活化能最低为84.2 kJ/mol且整体活化能随固化度的变化较小、固化更均匀。在2E4MI最佳用量(0.2份)下对固化体系进行等温DSC以及潜伏性测试,结果表明,该体系在160℃下20 min内可完成固化,室温储存15 d的固化度仅为0.146,说明其适合用作快速固化环氧树脂储存体系。     

脲衍生物对环氧树脂/双氰胺体系促进作用的研究

对比了不同结构的脲衍生物[3-(3-氯-4-甲基苯基)-1,1-二甲基脲(A)、3-(3,4-二氯苯基)-1,1-二甲基脲(B)、3-(4-氯苯基)-1,1-二甲基脲(C) ]对环氧树脂/双氰胺体系的促进作用。利用差示扫描量热仪和傅里叶变换红外光谱研究了3种环氧树脂/双氰胺/脲体系的反应活性和固化反应动力学。结果表明,体系A的最佳配比为：环氧：双氰胺：脲A=100：6：4（质量比,下同）,130 ℃时40 min就可以完全固化,其表观活化能（Ea）=64.66 kJ/mol,反应级数（n）=0.897;体系B的Ea=71.68 kJ/mol,n=0.930;体系C的Ea=71.03 kJ/mol,n=0.928;3种体系配制的胶液的室温剪切强度均大于20 MPa,体系A的粘接强度达到24.98 MPa。     

双氰胺改性酚醛泡沫塑料性能研究

针对酚醛泡沫塑料脆性大和强度低的缺点,采用双氰胺作为改性剂,对酚醛树脂及其泡沫塑料进行了改性研究,并将改性前后两种泡沫塑料的性能进行了对比。采用傅立叶变换红外光谱对酚醛树脂进行了结构表征,通过粉化率、冲击强度和压缩强度测试分析了改性酚醛泡沫塑料的脆性和力学性能,通过热失重分析了改性酚醛泡沫塑料的热稳定性,并采用极限氧指数仪测定了改性酚醛泡沫塑料的阻燃性能。结果显示,当加入的双氰胺用量为苯酚质量的3%时,改性酚醛泡沫塑料的综合性能最好,其压缩强度达到0.046 MPa,冲击强度达到3.36 k J/m2,粉化率低至2.13%,极限氧指数达到38.5%。相对于纯酚醛泡沫塑料,双氰胺改性酚醛泡沫塑料的力学性能有所提升,脆性明显改善。在热稳定性方面,纯酚醛泡沫塑料在340℃时已明显失重,而3%双氰胺改性酚醛泡沫塑料在370℃后才开始快速失重,热稳定性更好。随着双氰胺用量的增加,改性酚醛泡沫塑料的极限氧指数增大,阻燃性能有所提高。     

苯胺改性双氰胺固化剂的合成及性能研究

研究了苯胺改性双氰胺的合成工艺及其对环氧树脂固化性能的影响规律。苯胺改性双氰胺的最佳合成工艺条件为：浓盐酸和苯胺的摩尔比为1．1：1,双氰胺和苯胺的摩尔比为1．2：1,反应温度为90℃,反应时间为4h,产物收率可达88．35％。利用改性双氰胺固化环氧树脂制备涂层并测试其硬度,考察了固化剂与环氧树脂配比、固化温度和时间对涂层固化性能的影响规律。研究结果表明,最佳配比（质量比）为1：2．86,在130℃固化3．5h后,涂层硬度可达到1．39。与未改性双氰胺固化环氧树脂相比,其最低固化温度降低了30℃,且固化性能明显提高。     

曼尼希改性三元醚胺与双氰胺共固化环氧体系

对三元醚胺环进行了曼尼希反应改性。改性胺中含水量对双氰胺共混环氧体系拉伸剪切强度影响显著。讨论了不同原料配比产物对共混体系力学性能的影响,加入改性的三元醚胺后双氰胺环氧体系的柔性增加,剥离强度提高到7.48k N/m。动态热分析仪测试的结果显示,共混体系的玻璃化转变温度为95℃。     

GZQ型振动流化床干燥机在双氰胺干燥上的应用

介绍了ＧＺＱ振动流化床干燥机的性能、优点及该机在大氰胺干燥应用中取得的成效。     

水解连续化新工艺在双氰胺生产中的应用

针对国内间歇式水解和过滤工艺技术落后的局面，我厂经反复试验实现了水解连续化生产双氰胺的新工艺，从而使各项技术指标均达到和超过设计水平。