氟橡胶FE2605与G-755性能对比

氟橡胶是由两种或多种含氟烯烃共聚所得的含氟聚合物 ,氟橡胶经配合加工制成的硫化胶具有优异的耐燃油、油类、润滑剂和酸等特性及耐热性。日本大金公司的Ｇ 75 5是一种含多元醇硫化剂和硫化促进剂的二元氟橡胶 ,具有优异的耐甲醇性、耐低温性和耐热性 ,适用于燃油软管等产品的     

三种粘合剂在氟橡胶与金属粘合试验中的对比

应用粘合剂ＦＺ－１，Ｃｈｅｍｏｌｋ６０７和ＡＰＭ对国产和意大利产氟橡胶胶料与金属骨架进行粘合试验。粘附扯离强度试验表明，粘合剂ＦＺ－１是氟橡胶与金属粘合的优良粘合剂；意大利产氟橡胶与金属的粘合效果优于国产氟橡胶，氟橡胶的彩色胶料与金属粘合较之其黑色胶料易于粘合；双酚ＡＦ／促进剂ＰＰＣ作硫化体系的氟橡胶胶粘与金属粘合较之用３＃硫化剂的胶料更易于粘合。     

氟橡胶新型硫化促进剂2,3,5-三苯基四唑氯化物(TTC)的研究

本工作的研究目的是探索改善氟橡胶高温压缩永久变形的途径。以苯肼,苯甲醛和重氮盐为原料,通过三步法合成出一种氟橡胶周新型硫化促进剂TTC,并对其配合效能进行了试验。试验表明,以双酚AF(硫化剂)和TTC(促进剂)组成的硫化系统对2641型氟橡胶是有效的。含双酚AF/TTC的胶料具有良好的硫化特性和贮存稳定性,其硫化胶具有良     

意大利Tecnoflon氟橡胶组成及其硫化体系结构剖析

前言 Tecnoflon是意大利Monteflous公司生产的26型氟橡胶商品名称。近年来,该公司在开发低压缩永久变形氟橡胶及其硫化配合技术过程中,独创性地研制出一种新型硫化促进剂(他们称为Aminophosphonium Agent,简称M_2~2)。由此制得的氟橡胶压缩永久变形值为10～25     

氟橡胶与丁腈橡胶的硫化粘合

最近几年,汽车燃油管路系统中用的橡胶制品要求提高耐热性与耐燃油性,能满足这些性能要求的橡胶材料是氟橡胶。出于氟橡胶价格昂贵,与燃油接触的内层薄壁可以使用氟橡胶,而它的外层胶宜为常用的丁腈橡胶。为此,对氟橡胶与丁腈橡胶的硫化粘合进行了试验研究。试验结果是,要使氟橡胶与丁腈橡胶两者粘合:(i)丁腈橡胶部分要添加20份金属化合物(氢氧化钙);(ii)氟橡胶部分要把硫化促进剂(有机鏻盐)的用量增加到0.9份;(iii)宜采用与含有二乙氨基团的甲基丙烯酸酯共聚的丁腈橡胶。这样得到的氟橡胶与丁腈橡胶的硫化粘合,其粘接强度可达到橡胶层破坏的程度。其中采用以8.5wt%甲基丙烯酸乙酯共聚的丁腈橡胶显示最佳的粘合强度。另外,对氟橡胶与丁腈橡胶的共交联机理也进行一些探讨。     

B.P.C一种氟橡胶(新型)促进剂

据有关资料报道 :成都三爱富新材料实业有限公司最近研制成功了一种氟橡胶 (新型 )促进剂Ｂ .Ｐ .Ｃ ,该剂适用于氟橡胶多元醇硫化体系 ,在基本保持氟橡胶优异综合性能的基础上 ,可大幅度降低其压缩永久变形率 ,通常氟橡胶的压缩永久变形率在50 %左右 ,而加入本品后可使其压缩永久变形率降低至 10 %～ 15% (试验条件 :2 0 0℃× 2 4ｈ ,压缩率30 % ) ,从而提高了氟橡胶制品的密封性能和使用寿命 ,胶料流动性好 ,加工性能优异 ,贮存稳定。该产品质量和性能均优于苄基三苯基氯化磷 (Ｂ .Ｐ .Ｐ) ,达到国外同类产品标准。用量为 0 .5%～ 1%。本…     

B.P.C一种氟橡胶(新型)促进剂

据有关资料报道 :成都三爱富新材料实业有限公司最近研制成功了一种氟橡胶 (新型 )促进剂Ｂ .Ｐ .Ｃ ,该剂适用于氟橡胶多元醇硫化体系 ,在基本保持氟橡胶优异综合性能的基础上 ,可大幅度降低其压缩永久变形率 ,通常氟橡胶的压缩永久变形率在50 %左右 ,而加入本品后可使其压缩永久变形率降低至 10 %～ 15% (试验条件 :2 0 0℃× 2 4ｈ ,压缩率30 % ) ,从而提高了氟橡胶制品的密封性能和使用寿命 ,胶料流动性好 ,加工性能优异 ,贮存稳定。该产品质量和性能均优于苄基三苯基氯化磷 (Ｂ .Ｐ .Ｐ) ,达到国外同类产品标准。用量为 0 .5%～ 1%。本…     

配方因素对氟橡胶高温撕裂性能的影响

研究了硫化剂品种、双酚AF用量、促进剂BPP用量、补强剂品种及炭黑N990用量对不同测试温度下氟橡胶撕裂强度的影响,采用核磁共振法测定了不同温度下氟橡胶硫化胶的交联密度,研究了氟橡胶的高温撕裂强度与其交联密度间的关系。结果表明,随着测试温度的增加(25℃增加到200℃),不同配方的氟橡胶的撕裂强度均明显降低。在100~200℃温度范围内,双酚AF/BPP硫化的氟橡胶的撕裂强度高于过氧化物或胺类硫化氟橡胶的撕裂强度。随着双酚AF用量的增大,氟橡胶的常温撕裂强度明显降低,而高温撕裂强度略有下降。促进剂BPP用量增大,氟橡胶的常温和高温撕裂强度均变化不大。几种补强剂中,沉淀法白炭黑补强氟橡胶在200℃时的撕裂强度仅为25℃时撕裂强度的0.6%。测试温度从25℃升至200℃,炭黑N990补强氟橡胶的撕裂强度降低幅度较小,随着N990用量的增大,氟橡胶的常温撕裂强度增幅明显,而高温撕裂强度略有提高。测试温度升高,氟橡胶硫化胶的交联密度减小,同时撕裂强度也降低,双酚硫化时,在相同测试温度下,氟橡胶的交联密度越小,撕裂强度越大。     

核-壳型双活性丙烯酸酯弹性体改性氟橡胶及其制备方法

<正>本发明公开了一种核-壳型双活性丙烯酸酯弹性体改性氟橡胶的制备方法,先将氟橡胶生胶、氟橡胶接枝马来酸酐增容剂、核-壳型双活性丙烯酸酯弹性体和橡胶补强剂,加入到密炼机中,在120~170℃下,熔融50~120 min共混出氟橡胶母胶;再将氟橡胶母胶,加入橡胶补强剂、硫化剂、促进剂、吸酸剂,升温至     

氟橡胶预混胶(38元·kg~(-1))

正广州市泰烨橡胶有限公司经过多年技术研发及不断攻关试验改进,率先在国内成功研制出的价格低廉的通用型氟橡胶预混胶,材料为进口双酚硫化型氟橡胶,在高端氟橡胶制品中广泛使用,可以并用在氟橡胶生胶配方中,也可以并用在氟橡胶混炼胶中。在原有产品质量的基础上提升多项性能指标的同时降低生产成本,有效提高企业的产品竞争力。实验测试报告:采用四川晨光氟橡胶BDF401P,在原配方不变的基础上分别并用50,40,30和20份通用型氟橡胶预混胶,产品的耐油性、拉伸强度、拉断伸长率、100%定伸应力在原有基础上均有不同程度的提升,并且大幅改善氟橡胶胶     

从废旧高温合金的硫酸浸出渣中浸出分离钨钼铼

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%.     

Aggregation pheromone system of adult gregarious desert locust schistocerca gregaria (forskal)

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.     

生物基1,6-己二醇的研究进展

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。     

Selected Quality Attributes of Dried Foods

Major quality parameters associated with dried food products are the color, visual appeal, shape of product, flavor, microbial load, retention of nutrients, porosity bulk density, texture, rehydration properties, water activity and chemical stability, preservatives, and freedom from pests, insects and other contaminants, as well as freedom from taints and off-odors. These parameters need to comply with the specifications of customers and regulations of different importing countries and often can adversely affect the acceptability of dried products. Therefore, quality of dried food products depends on many factors, such as raw materials, processing environment, packaging, microbial stability, use of additives, and temperature of storage. This review highlights selected quality attributes of dried food products and discusses ways of optimizing them.     

深入探索智能算法与反应网络研究的融合

反应网络是化工过程机理在微观分子尺度上的表达方式，但网络的复杂性为深入认识生产过程提出了挑战。本文提出了探索智能算法与反应网络研究融合的思路，基于物质转化的“透明工程”的概念，深入剖析反应网络的结构统计指标、结构拓扑特征、节点性质特征、机理动态演化、建模应用性能等特点。随后阐述了使用“数据结构化、智能优化与分析、智能代理建模”三步结合的机理数值化反应网络研究方法，既实现了在微观层面的局部放大，又实现了在工业应用中的准确预测。文中指出，智能算法融合反应网络后可以对实际工业过程执行可视化、可解释性的建模、分析与优化，为相关工业生产提质增效提供决策依据，并进一步帮助人类突破认知的极限，更深入地理解反应过程，提取关键的反应规律，助力化学工业的智能化。     

金属纳米颗粒辅助木质纤维素暗发酵生物制氢的研究进展

通过文献计量学分析表明暗发酵制氢是目前研究最热门的生物制氢方法,Fe、Ni、Co、Ag等金属纳米颗粒作为该领域研究热点可改善暗发酵制氢存在底物转化率与产氢效率均有待提高的难题。介绍了金属纳米颗粒的特点、生物相容性及其与酶、微生物细胞的作用机理,进一步从促进木质纤维素水解影响产氢、对水解酶的固定化影响产氢、提高氢化酶活性影响产氢、调控发酵微生物细胞代谢和促进细胞电子传递影响产氢、改善微生物群落结构影响多菌群协同产氢等几个方面对典型金属纳米颗粒辅助木质纤维素暗发酵产氢的研究现状进行综述,并对金属纳米颗粒应用于暗发酵产氢存在的难点及前景方向进行了展望。     

铁氧体磁性材料的吸波机理及改善吸波性能的研究进展

铁氧体吸波材料具有吸收频段宽、吸收率高、匹配厚度薄等优点,但由于存在密度大、频带较窄、高温特性差等问题,难以满足吸波材料“薄、轻、宽”的特性,限制了铁氧体吸波材料的应用。本文介绍了吸波材料的吸波机理及铁氧体吸波材料的研究进展,结合近几年铁氧体吸波材料的的发展现状,概述了改善铁氧体吸波材料吸波性能的方法,进而展望了吸波材料的发展前景。总结得出对铁氧体吸波材料进行纳米化、复合化、掺杂及改变形貌,进一步研究和开发出性能优良的吸波材料并将其应用到工业化生产中,是未来制备高性能吸波材料的发展方向。     

Emerging role of nanobiocatalysts in hydrolysis of lignocellulosic biomass leading to sustainable bioethanol production

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.     

Soil nutrient depletion by agricultural production in Southern Mali

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.     

农药制剂功能性的研究

简述了农药制剂的功能性——润湿、附着、渗透等性能对农药制剂活性成分的影响,以及制剂的表面张力、接触角、粘度、渗透力对农药制剂的润湿、附着、渗透等性能的影响。