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1.
高苯乙烯橡胶   总被引:1,自引:0,他引:1  
本文介绍高苯乙烯橡胶生产的工艺技术,及其所用原料高苯乙烯树脂胶乳、丁苯橡胶-1502胶乳的聚合配方、工艺流程、操作条件等。  相似文献   

2.
利用傅里叶红外光谱(FTIR)、核磁共振谱(NMR)等手段对不同色度的C9石油树脂进行表征,以期获得有关树脂骨架结构的信息。结果表明:C9树脂是以苯乙烯、(邻,间,对)-甲基苯乙烯、茚、甲基茚等结构单元为主体的热塑性芳烃石油树脂。各结构单元的相对含量不同导致树脂性质的差异。  相似文献   

3.
茚-古马隆树脂在焦化产品中占有重要位置,下塔吉尔钢铁公司焦化厂精制车间茚-古马隆树脂工段是俄罗斯透明茚-马隆树脂的唯一生产需求没有减少,例如:1993的与1985年相比,该种馏分的供应量减少了一增,从6948t/a十降到3098t/a,而且原料供应厂家明显减少,新库兹蒋钢铁公司焦化厂是茚-古马隆馏分的主要供货厂家。  相似文献   

4.
浅色度C9石油树脂的研究I.树脂合成与生色机制   总被引:7,自引:1,他引:6  
在较温和条件下俣成了浅色度C9石油树脂,用裂解气体相色谱(PGC),红外光谱(IR)及核磁共振(NMR)等手段进行了表征。结果表明,C9石油树脂是以苯乙烯,甲基苯乙烯,环戊二烯,甲基环戊二烯,茚等为骨架结构成的线型热塑性树脂,其色度的不同环二烯,甲基环戊二烯,茚,甲基茚,萘等生色因素含量不同及共轭程度不同所致,树脂链中超共轭结构是主要生色机制。  相似文献   

5.
在较温和条件下合成了浅色度C_9石油树脂,用裂解气相色谱(PGC)、红外光谱(IR)及核磁共振(NMR)等手段进行了表征。结果表明,C9石油树脂是以苯乙烯、甲基苯乙烯、环戊二烯、甲基环戊二烯、茚等为骨架构成的线型热塑性树脂,其色度的不同是环戊二烯、甲基环戊二烯、茚、甲基茚、萘等生色因素含量不同及共轭程度不同所致。树脂链中超共轭结构是主要生色机制。  相似文献   

6.
以碳九馏分、苯乙烯类树脂油、茚类树脂油和循环溶剂为原料,通过选择合适的配比来调控碳九中的活性组分含量,研究了碳九中主要的活性组分含量对冷聚合成石油树脂性能的影响。实验发现反应原料中苯乙烯类单体含量的增加能够降低树脂的软化点;茚类和甲茚类活性组分含量影响树脂的色相;但在该体系中,双环戊二烯含量的增加与树脂收率成反比。因此,在实际生产中,为了生产出满足要求的石油树脂产品,可以根据活性组分的不同及时调整生产工艺,以保证产品的质量。  相似文献   

7.
α-甲基苯乙烯的利用   总被引:2,自引:0,他引:2  
α-甲基苯乙烯是异丙苯法联产苯酚和丙酮时的副产物,可用其合成佳乐麝香、开司米酮、龙葵醇及酯类等香料;也用于制造某些聚合物,如α-甲基苯乙烯-丙烯腈共聚物、α-甲基苯乙烯-苯乙烯-丙烯腈共聚物、α-甲基苯乙烯-丙烯腈共聚物改性ABS树脂等。本文介绍了上述几种香料的合成路线和几种共聚物的制造方法,并强调了α-甲基苯乙烯的开发利用价值和前景。  相似文献   

8.
世界聚氯乙烯工业技术进展(2001).I   总被引:2,自引:1,他引:2  
介绍了2001年世界主要国家和地区聚氯乙烯市场和工业现状。在氯乙烯单体生产技术方面,叙述了以乙烯为原料使用四氯乙烯和四氯化碳作氯化剂生产氯乙烯的新工艺,干电解氯化氢转化为氯的新工艺,乙烷直接氧氯化生产氯乙烯的新技术;分析了国外大型聚氯乙烯公司生产氯乙烯单体的工艺特点及采用不同工艺生产氯乙烯的经济效益。在聚氯乙烯树脂生产技术方面,总结了连续悬浮聚合氯乙烯新工艺,使用茂金属催化剂生产聚氯乙烯树脂的新技术;介绍了生产高表观密度聚氯乙烯树脂、消光聚氯乙烯树脂、聚氯乙烯-聚(N-异丙基丙烯酰胺)接枝共聚物、聚氯乙烯发泡树脂、易加工聚氯乙烯树脂及氯乙烯-丙烯酸酯-苯乙烯接枝共聚物的新方法。分析了国外经济规模聚氯乙烯生产装置的经济效益,总结了国外聚氯乙烯加工应用技术的进展,并对发展我国聚氯乙烯工业提出了建议。  相似文献   

9.
形状记忆树脂的开发与应用   总被引:2,自引:0,他引:2  
论述了形状记忆树脂的形状记忆原理,介绍了目前已开发成功的聚降冰片烯、反式1,4-聚异戊二烯、苯乙烯-丁二烯共聚物和聚氨酯等形状记忆树脂的性能与制备方法,探讨了它们的应用领域。  相似文献   

10.
ABS树脂的共混改性   总被引:1,自引:0,他引:1  
简要介绍了采用聚氯乙烯、聚碳酸酯、热塑性聚氨酯单体等不同热塑性塑料对丙烯腈-丁二烯-苯乙烯三元共聚物(ABS)树脂进行共混改性,从而提高ABS树脂的性能,并且对共混改性的机理进行了探讨,指明了不同组分对ABS树脂性能的影响。  相似文献   

11.
丁璟  赵俊琦  程时标  慕旭宏  宗保宁 《化工进展》2015,34(12):4209-4213
传统的以石油化工产品为原料的石化基1,6-己二醇(1,6-HDO)的生产存在能耗高、反应产物分离困难、污染环境等缺点,以5-羟甲基糠醛(5-HMF)为原料制备生物基1,6-HDO可以克服这些缺点。本文介绍了国内外制备生物基1,6-HDO的研究进展,总结并讨论了由5-HMF制备1,6-HDO的不同反应路径,并从反应物吸附、金属粒径、活性组分协同作用、载体等角度对比了不同催化剂体系及其催化机理,探讨了各种催化剂促进C=O加氢、呋喃环C=C加氢、呋喃环C—O氢解开环反应,抑制呋喃环、呋喃环侧链C—C氢解断裂反应的性能。与多步法相比,一步法制备1,6-HDO的反应步骤简单,但1,6-HDO的产率相对较低,因此开发高效的催化剂体系和反应工艺将是今后研究的重点。  相似文献   

12.
Catalytic conversion (hydrolysis) of carbohydrate polymers present in the lignocellulosic biomass into fermentable sugars is a key step in the production of bioethanol. Although, acid and enzymatic catalysts are conventionally used for the catalysis of various lignocellulosic biomass, recently application of immobilized enzymes (biocatalysts) have been considered as the most promising approach. Immobilization of different biocatalysts such as cellulase, β-glucosidase, cellobiose, xylanase, laccase, etc. on support materials including nanomaterials to form nanobiocatalyst increases catalytic efficacy and stability of enzymes. Moreover, immobilization of biocatalysts on magnetic nanoparticles (magnetic nanobiocatalysts) facilitates easy recovery and reuse of biocatalysts. Therefore, utilization of nanobiocatalysts for catalysis of lignocellulosic biomass is helpful for the development of cost-effective and ecofriendly approach. In this review, we have discussed various conventional methods of hydrolysis and their limitations. Special emphasis has been made on nanobiocatalysts used for hydrolysis of lignocellulosic biomass. Moreover, the other most important aspects, like nanofiltration of biomass, conversion of lignocellulose to nanocellulose, and toxicological issues associated with application of nanomaterials are also discussed.  相似文献   

13.
Six electrophysiologically active aromatic compounds, viz., anisole, benzaldehyde, veratrole, guaiacol, phenylacetonitrile, and phenol, were identified in the volatiles of older-adult male desert locust. Young adults and females of all age groups produced none or only trace quantities of these compounds. Comparison of the aggregation responses of young and older adults to the crude, older-adult, volatile extract and different synthetic blends of the six compounds showed that the aggregation pheromone system of the adult gregarious locust consists of phenylacetonitrile, guaiacol, phenol, and benzaldehyde. Like the crude volatile extract of older males, neither the synthetic blend of the six compounds nor the adult pheromone blend evoked any significant aggregation responses from nymphs. These results confirm our previous report of sexual differentiation in the production of adult aggregation pheromone in the desert locust and of the evidence of two distinct aggregation pheromone systems in the two stages of the insect.  相似文献   

14.
The degree of soil mining by agricultural production in Southern Mali is assessed by calculating nutrient balances: differences between the amount of plant nutrients exported from the cultivated fields, and those added to the fields. Export processes include extraction by crops, losses due to leaching, to erosion, and to volatilization and denitrification. Inputs include applications of fertilizer and manure, restitution of crop residues, nitrogen fixation, atmospheric deposition of nutrients in rain and dust, and enrichment by weathering of soil minerals. Nutrient balances are calculated for N, P, K, Ca, and Mg. Both pessimistic and optimistic estimates are given.The resulting figures indicate, even when the most optimistic estimates are used, large deficits for nitrogen, potassium and magnesium. For the region as a whole, the calculated deficits are -25 kg N/ha,-20 kg K/ha, and -5 kg Mg/ha. Further, acidification is to be expected, in particular in areas where cotton is grown. The deficits are caused by traditional cereal crops, but also by cotton and especially by groundnut. The latter two crops are fertilized, but insufficiently. It is important to note, that the negative figures are not automatic recommendations for application of a specific amount of additional fertilizer. For phosphorus and calcium the balance of the region as a whole appears to be about in equilibrium, but locally large variations may occur.Erosion and denitrification are important causes of nutrient loss, accounting respectively for 17 and 22% of total nitrogen exports. Atmospheric deposition and weathering of minerals in the soil are still important nutrient inputs that contribute as much as nutrients as organic and mineral fertilizer combined. Nutrient depletion is very large in comparison to the amount of fertilizer applied. Drastic options, such as doubling the application of fertilizer or manure, or halving erosion losses, even if feasible, would still not be enough to make up for the calculated deficits.The annual value of withdrawn nutrients, if related to prices of fertilizers, varies between 10,000 and 15,000 FCFA/ha (40-60 US $/ha). Since the estimated average gross margin from farming in this area is 34,000 FCFA/ha (123 US $/ha), soil mining appears to provide an amount equal to 40% of farmers' total income from agricultural activities.  相似文献   

15.
Part I of this article dealt with the appearance of metallic materials observed at a distance of a few meters. This part deals with the appearance at reading distance. Metallic materials exhibit various appearance attributes, including glitter, glints, depth, coherence glitter, binocular luster, binocular glitter, and binocular mottle. Color disparity is proposed as a measure of binocular luster. Metallic materials resemble grainy photographs, so the method used in photography to quantify graininess by measuring blending distance is introduced. Objective measures of granularity are proposed as correlates of graininess. The term “subsurface” is applied to the apparent “surface” lying beneath the glossy surface. Methods of optical image analysis, such as point spread function, edge spread function, Wiener spectrum, modulation transfer function, and image correlation are proposed to characterize the appearance of metallic surfaces. Polarization and cylindrical presentation may aid measurements. Binocular attributes of appearance introduced here require analysis of the disparity between two points of view. New kinds of pigments may require new methods of measurement. © 1998 John Wiley & Sons, Inc. Col Res Appl, 23: 362–373, 1998  相似文献   

16.
杜凯敏  范杰 《化工进展》2019,38(6):2697-2706
开发新型丙烯制备工艺对于满足人们日益增长的丙烯需求具有重要意义。由于商业化无氧脱氢技术存在热力学平衡限制、反应温度高、催化剂易积炭等不足,近年来,人们将研究重心转向了丙烷氧化脱氢技术。本文简述了丙烷氧化脱氢制丙烯的发展现状,综述了近年来文献报道的丙烷氧化脱氢催化剂体系(V基、Cr基、Co基、Ni基、Mo基、Pt基、Ce基和非金属基催化剂)、机理研究和不同氧化剂选择,并对各自的优势和不足进行了简单分析。分析发现,虽然目前丙烷氧化脱氢催化剂的种类非常广泛,但产物丙烯的收率仍有待提高,机理研究也需要更加系统和深入。最后指出,系统研究丙烷氧化脱氢机理,并在此基础上开发先进催化剂,进一步提高丙烯的选择性和收率是未来丙烷氧化脱氢研究的重要方向。  相似文献   

17.
对废旧高温合金硫酸浸出残渣选择HCl-FeCl3-H2O2体系氧化浸出、浸出后加入NaOH调节溶液pH值,使钨、钼、铼与铌、钽等分离,研究了反应时间、反应温度、HCl用量、FeCl3用量、H2O2用量对钨、钼、铼浸出率的影响. 结果表明,该体系能充分浸出渣中钨、钼、铼3种金属,添加FeCl3可提高钼在盐酸溶液中的浸出率. 在浸出温度70℃、浸出时间5 h、FeCl3用量100 g/L、H2O2用量10 mL/g及HCl初始用量10 mL/g的条件下,钨、钼、铼浸出率分别大于97%, 86%, 91%.  相似文献   

18.
镍基催化剂是一种由多孔结构的镍铝合金的细小晶粒组成的固态异相催化剂。镍基催化剂因具有机械强度高、催化活性好、制备简单、价格低廉等优点,被广泛地应用到石油、化工、制药、油脂、香料、双氧水、合成纤维等方面的加氢、脱氢、脱卤、脱硫等转化反应过程中。随着催化工业的逐步发展,对催化剂性能的要求也越来越高,原始的镍基催化剂利用率低、抗酸性差等缺点限制了该催化材料的进一步应用。因此,近年来,许多研究者一直在尝试对镍基催化剂进行改性,以改善其使用寿命、催化活性、抗酸性等性能。着重介绍了镍基催化剂的强化措施以及镍基催化剂的应用,并对镍基催化剂在各类催化反应中的应用情况进行了详细概述,在此基础上展望了镍基催化剂的未来发展。  相似文献   

19.
氨基纤维素是末端带有氨基的纤维素衍生物,化学结构与壳聚糖相似。氨基基团的引入使纤维素大分子具有很好的溶解性、成膜性和吸附重金属离子特性,并在酶的固定、药物缓释等生物领域有很好的应用前景。氨基纤维素的合成过程相对复杂,主要体现在中间产物的制备以及氨基纤维素的合成2个阶段,其合成过程的选择性和经济性较差,导致氨基纤维素的生产和应用受限。笔者主要对氨基纤维素的合成途径进行了综述,并对氨基纤维素的膜保护、固定酶和吸附等应用进行了总结。  相似文献   

20.
齐亚兵 《化工进展》2022,41(11):6068-6079
活化过硫酸盐氧化法因具有经济、高效、环保、安全稳定等优势,近年来在酚类污染物的降解中备受关注。目前活化过硫酸盐降解酚类污染物的方法主要包含外加能量活化和外加催化剂活化两大类。其中单一的热活化、光活化、超声活化、电化学活化、等离子体活化等外加能量活化过程能量消耗较大,且对酚类污染物不易达到满意的降解效果。过渡金属活化和碳质材料活化等外加催化剂活化方式,由于环境污染小、操作成本低、降解率高等优点,越来越受到科研工作者的重视。为了提高对酚类污染物的降解率,不同的过硫酸盐活化方式不断融合,逐渐形成多种耦合活化方式,例如,碳质材料与过渡金属的耦合活化、电化学与过渡金属催化剂的耦合活化以及光与外加催化剂的耦合活化等。本文论述了活化过硫酸盐氧化法降解酚类污染物的研究进展,概述了活化过硫酸盐的影响因素,分析了活化过硫酸盐降解酚类污染物存在的问题,展望了活化过硫酸盐降解酚类污染物的发展方向。  相似文献   

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