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1.
为了提高产率,以对乙酰氨基酚和三氯硫磷为原料采用酰胺水解法合成了硫代磷酸三(4-氨基苯)酯,通过实验得到了合成的最佳工艺条件:各原料物质的量之比为n(对乙酰氨基酚)∶n(三乙胺)∶n(三氯硫磷)=3.10∶3.80∶1,反应温度为35℃,反应时间为3.5h.红外光谱、核磁共振谱、质谱和高效液相色谱等手段对产品进行了结构表征.通过对实验方法的进一步研究,结果发现在三乙胺中加入少量的吡啶,组成复式缚酸剂后,能有效地提高反应的产率.在此优化工艺条件下,产率为84%.  相似文献   

2.
以精制棕榈油为原料,与无水乙醇进行酯交换反应制取生物柴油。探讨了反应物配比、催化剂用量、温度、反应时间等因素对产物产率的影响,采用正交实验优化合成条件确定了最佳合成条件及影响反应的关键因素,并运用气相色谱-质谱技术分析了产物的结构和组成,运用核磁共振技术对主要成分进行了结构确定。结果表明该生物柴油符合《柴油机燃料调和用生物柴油国家标准》(GB/T20828-2007),接近美国和德国的生物柴油标准,基本符合《轻柴油》(GB252-2000),适于中小规模及大规模生产应用。  相似文献   

3.
以间苯二酚为原料,经过发烟硫酸磺化、浓硝酸硝化以及水解反应可制备4,6-二硝基间苯二酚(DNBDO),该方法具有原料易得、产品纯度高、产率高等诸多优点。本文用正交实验设计对该合成方法进行了研究,得出了最优化的反应条件。  相似文献   

4.
以三氟丙基甲基环三硅氧烷(D3F)和六甲基环三硅氧烷(D3)为原料,1,3-二(3-羟丙基)-1,1,3,3-四甲基二硅氧烷(BHTS)为封端基,硅烷醇钠为引发剂,邻苯二甲酸二甲酯(DMP)为促进剂,采用阴离子开环聚合的方法制备双羟基含氟聚硅氧烷(PDMFS),采用红外光谱和核磁共振氢谱等方法对产物结构进行了表征和确认,探讨了DMP在D3F和D3共聚合过程中的促进作用,研究了合成反应中催化剂用量、促进剂用量、反应温度以及反应时间对聚合反应产率的影响。结果表明:100℃下聚合,引发剂加入量为500×10~(-6),DMP浓度为0.2mol/L,反应100min,PDMFS的产率,达到88.2%,说明,在此聚合反应条件下链反咬副反应得到很好的抑制。  相似文献   

5.
以香草醛为原料,在乙醇介质中与1,3-二溴丙烷反应生成1,3-二(4-甲酰-2-甲氧基苯氧基)丙烷,然后在甲醇介质中进行硼氢化还原,最后在甲酸介质中聚合,合成笼形超分子主体化合物Cryptophane E.采用核磁共振谱(1H NMR、13C NMR)、质谱(MS)、紫外光谱(UV)荧光光谱、红外光谱、元素分析等测试技术对Cryptophane E进行表征,重点考察反应温度、时间及原料配比等因素对合成产率的影响,获得最佳反应条件,并深入探讨了合成机理.  相似文献   

6.
以甲醇为溶剂,草酸二乙酯与单乙醇胺为原料制备了N′,N-二-(2-羟乙基)-草酰胺,并对其进行红外光谱分析。研究溶剂用量、反应物配比、反应温度与保温时间对N′,N-二-(2-羟乙基)-草酰胺产率的影响。结果表明:最佳工艺条件为甲醇作溶剂,甲醇与草酸二乙酯质量比=5∶1,反应物摩尔比n(草酸二乙酯)∶n(单乙醇胺)=1∶2.3,反应温度为70℃,保温时间1.5h,此时N′,N-二-(2-羟乙基)-草酰胺产率达到97.1%。  相似文献   

7.
以α-萘酚与N-羟甲基丙烯酰胺为原料,经Friedel-Crafts反应合成了荧光单体2,4-二-N-甲基丙烯酰胺-α-萘酚并进一步合成其自聚物。考察了催化剂用量、反应温度、原料物质的量比、反应时间对产率的影响。分别用超导核磁共振谱仪和元素分析仪对产物结构进行分析,并对单体与自聚物的荧光性能进行了对比。结果表明,最佳反应条件为:n(α-萘酚)∶n(N-羟甲基丙烯酰胺)=1∶2,V(溶剂)∶V(催化剂)=10∶1,反应温度40℃,反应时间5h。聚合物的荧光强度高于单体的荧光强度。  相似文献   

8.
以对苯醌和9,10-二氢-9氧杂-10-磷杂菲-10-氧化物(DOPO)为原料,采用微波法合成了10-(2,5-二羟基苯基)-9,10-二氢-9氧杂-10-磷杂菲-10-氧化物(ODOPB)。通过核磁共振氢谱以及红外光谱对其结构进行了表征。讨论了投料比、反应时间以及反应温度对ODOPB产率的影响。确定了优化的合成工艺条件,即反应物配比n(苯醌)∶n(DOPO)=0.21∶1,反应温度为54℃,微波辐射功率为300W,辐射时间为5min。结果显示该条件下ODOPB产率为96.5%,产物的初始热分解温度为278℃,800℃残炭量达到33.5%;当产物添加量为15%时,LOI增加6个单位。  相似文献   

9.
陈欢  汪宗涛  陈仕清  范东斌 《材料导报》2021,35(20):20190-20194
通过脱甲基化改性提高酶解木质素酚羟基含量,以增加其环氧化反应活性,并于碱性条件下与乙二醇二缩水甘油醚(EGDE)反应合成木质素环氧接枝物(EPDL);将其作为交联剂与大豆蛋白复合制备高性能绿色大豆蛋白胶黏剂.采用核磁共振磷谱(31 P-NMR)以及红外光谱(FTIR)等分析手段对脱甲基木质素(DL)及其EPDL进行分析表征,研究了木质素脱甲基化前后羟基含量、接枝物环氧值及其化学结构的变化规律,考察了EPDL对大豆蛋白胶黏剂耐水胶合性能的影响.结果表明:脱甲基化改性明显提高了木质素羟基含量,其羟基含量较原木质素(L)提高了近29%,且通过微波加热处理可有效缩短木质素脱甲基化时间;脱甲基化改性使EPDL接枝上了较多环氧基团,其环氧值达到0.350 mol/100 g,增加了与大豆蛋白分子的交联反应活性;EPDL通过与大豆蛋白分子上羟基、氨基发生交联反应形成耐水化学结构,提高了大豆蛋白胶黏剂的耐热性和胶合性能,当EPDL用量为7%时,大豆蛋白胶黏剂湿胶合强度高达1.14 MPa,满足GB/T9846-2015国家标准规定的Ⅱ类胶合板要求.  相似文献   

10.
张曼  赵敏 《化工新型材料》2019,47(8):140-142,147
以乙酰乙酸乙酯和间苯二酚为原料,通过佩克曼(Pechmann)缩合反应,在催化条件下制备4-甲基-7-羟基类香豆素。在冰乙酸中,使六次甲基四胺与4-甲基-7-羟基类香豆素反应,控制反应温度为90℃,得到4-甲基-7-羟基-8-醛基类香豆素,制备的产品进一步与乙二胺在无水条件下反应生成荧光探针乙二胺缩-8-醛基类香豆素(L_1配体)。利用荧光光谱和紫外-可见吸收光谱对L_1配体进行表征,结果表明加入Co~(2+)离子的L_1配体紫外光谱有明显的变化,其荧光光谱发生猝灭。此探针可用于检测微量Co~(2+)离子。  相似文献   

11.
Permeable crystalline materialcan permeate into pores and cracks of concrete and catalyze the reaction between Ca(OH) 2and unhydrated cement to generate a great quantity needle non-soluble crystals, which can stop up the pores and cracks of concrete, and increase the impermeability of concrete. This paper reported the results of a study conducted to evaluate steel reinforcement corrosion of concrete specimens uncoated and coated with permeable crystalline material as well as mixed with the permeable crystalline material. The properties evaluated for corrosion test were water impermeability, water absorption, compressive strength and potential. The results of water impermeability, water absorption, compressive strength clearly showed that the permeable crystalline material could prohibit water, any soluble salts and moisture from penetrating the concrete to cause corrosion, leaking, and other problems, and it did increase the compressive strength, which was favorable for protection of corrosion of reinforcing steel. Moreover, it was concluded from the potential-time curve that the steel reinforcement of uncoated specimen was in the state of activation whereas that of other specimens coated and mixed with the permeable crystalline material was in the state of inactivation. Above all, it was indicated that the permeable crystalline materialis very effective to protect the steel reinforcement of concrete from corrosion.  相似文献   

12.
In this paper, the principle of spurting take off lacquer were introduced; and with orthogonal method the unsaturate polyester was prepared ;it was easy to peel airplane paint layer off with this material and equipment.  相似文献   

13.
Quality Study of Honeycomb Core Shaping Without Wax Stabilization   总被引:1,自引:0,他引:1  
Sandwich panels utilizing honeycomb cores result in lightweight, high-strength units that are very rigid. Indeed, they give honeycomb panels the best strength-to-weight ratio of any construction type available. Conventionally, the wax is poured into the cell of the core to strengthen the structure and prevent the core from being crushed during milling. Much time and labor is required to wax, mill, and clean the cores. In this study, the process of pouring wax into the core was skipped. In other words, the cutter directly milled the core. Experiments showed that the compressive strength of the core produced without wax stabilization was only 3% lower than that of cores produced using the traditional method. In addition, the drum peel strengths of cores produced without wax stabilization were 38.4% higher than cores produced using the traditional method, in which residual wax seriously polluted the adhesive. It was also found that eliminating the wax process can reduce costs.  相似文献   

14.
Polylactic acid (PLA) is one of the most widely used open source fused filament fabrication materials due to its ease of extrusion, biodegradability, and mechanical strength. The mechanical strength of PLA largely depends on the proper growth of its semi-crystalline structure, which can be severely impaired by a low rate of crystallization, particularly in open source printers. This can be further aggravated by the non-uniform thermal distribution of heat that causes improper curing among the extruded beads of the printing material. As a result, PLA printed on open source printers does not achieve the best mechanical properties. This research, for the first time, proposes an additive-free solution implemented through a detailed set of experimentation to improve the curing rate through in-process temperature variations to cure the joints among the beads. Scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) spectroscopy is used to confirm the improvements in the bead joints. This work is conducted in two phases of experiments. In the first phase, a full factorial ANOVA is used to investigate various process parameters and the important variables are used in the second phase to print test specimens in four different sets.  相似文献   

15.
In continuous hot-dip galvanization process the corrosion and chemical stability of the sink roll in the galvanizing bath are important problem which effects on the quality and productivity. In order to protect the sink roll the carbide cermet and/or ceramic coatings were deposited on the surface of the sink roll. The WC-, Cr3 C2-cermet coatings were deposited by high velocity oxygen fuel (HVOF) spray, respectively. The coating samples were immersed in molten Zn-alloy containing 50 wt % aluminum at 833 K for 24 hr and 144 hr, respectively. The inter-diffusion and inter-reaction of Zn, Al and elements in coating and corrosion behaviors of these coatings were investigated by XRD, SEM and EPMA etc. The corrosion mechanisms of the carbide cermet coatings and ceramic coatings in molten High Al-Zn-alloy were approached.  相似文献   

16.
In many situations, ice often adheres to a cooling solid surface, frequently causing serious accidents. It is critical to clarify the mechanism of ice adhesion to the cooling surface in order to prevent ice adhesion. In a past study, the shearing stresses of two kinds of test plates with a copper surface having the higher thermal conductivity were measured. The shearing stress corresponds to ice adhesion force. Both shearing stresses were significantly different; however, the cause remains unclear.Therefore, the present study focuses on an oxide layer as the main factor causing the difference of both shearing stresses; the influence of the oxide layer formed on shearing stress was discussed. And in the removal and reformation processes of the oxide layer, the time variation of the shearing stress was clarified. Moreover, the relationship between the state of the copper surface and the shearing stress was also clarified by surface analysis.  相似文献   

17.
During his inspection in Henan Province in May, Chinese President Xi Jinping stressed to "push forward the transformation from China Speed to China Quality, from Made in China to Created in China, and from Chinese Products to Chinese Brand". The "Three Transformations" are the specific requirements and goal of China's national development in the context that market should play a decisive role in the allocation of resources.  相似文献   

18.
正When you are enjoying the green,energy-saving and healthy lighting of IKEA LED luminaire,you may not realize that most of IKEA’s LED bulbs are produced by the LED luminaire smart manufacturing system of Hangzhou Zhongwei Photoelectricity CO.,LTD(ZVISION).No longer enclosed in the laboratory,the product standards are brought into the factory workshop and even to the entire production process.Thus,the standards are promoted and applied in a favorable way by enterprises,benefitting consumers with high quality products.  相似文献   

19.
正The international standard,ISO 8124-6,Safety of toys–Part 6:Certain phthalate esters in toys and children’s products,was officially issued by ISO worldwide on August 15.It was the first time for Chinese experts to lead the ISO standard development in toys industry.The standard was drafted by a group of Chinese experts from SAC/TC for toys and relevant Chinese departments and finally completed by a dedicated international group of experts.ISO 8124-6 makes a substantive breakthrough in the aspects of the scope of toys,limitation of plasticizer types,control of test cost,accuracy of test,operation convenience,etc.,offering the operational guidance for toy manufactures and testing laboratories.  相似文献   

20.
正SAC Administrator Tian Shihong led the Chinese delegation to visit the Spanish Association for Standardization and Certification(AENOR)on September 15,2014.Mrs.Begona Cristeto,the Vice-Minister of Industry,Energy and Tourism of Spain,and Mr.Avelino Brito,the President and CEO of AENOR greeted the delegation.The two sides had a deep and friendly discussion on strengthening the cooperation between China and Spain in the standardization field and promoting the standardization work to support the development of economy and trade in the two countries.  相似文献   

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