国内外苯酚的供需现状及发展前景

目前,全球苯酚的总生产能力约为926万ta/,2004年总消费量为774.5万t,预计到2009年总消费量将达到约945.2万t。2005年我国苯酚的总生产能力约为54.0万ta/,产量为44.3万t,消费量约为73.3万t。预计到2007年和2010年我国苯酚的总生产能力将分别达到约85万ta/和110万ta/,消费量将分别达到约85.0万t和96.0万t。针对目前存在的问题,提出了我国苯酚今后的发展建议。     

Kinetics and mechanism of the hydrolysis and alcoholysis of alkoxysilanes

As part of our work with the use of silane coupling agents, we have been investigating the transformations of alkoxysilancs into siloxanes. The influence of a para-substituted phenyl group attached to the silicon was investigated and the rates of acid catalyzed hydrolysis and alcoholysis of these para-substituted phenylalkoxysilanes have been determined. The kinetics and mechanism of the reactions are presented. These reactions are of interest because of their role in the use of silane coupling agents as adhesion promoters, in the preparation of zinc-rich silicate coatings, in the sol-gel process and in the preparation of silicones in general. The hydrolysis reaction was found to be first order in acid, zero order in water and to have a Hammett p of -1.42 when catalyzed by sulfuric acid. These results are consistent with current opinion that the reaction mechanism is SN₁, and involves a positive intermediate, possibly a siliconium intermediate. The alcoholysis reaction was found to be first order in both the silane and the catalysts, and of intermediate order in the alcohol, when catalyzed by carboxylic acids. When catalyzed by dichloroacetic acid, the reaction has a Hammet p value of +0.43. This is consistent with a concerted displacement reaction between the alkoxysilane and the complex involving the alcohol and the carboxylate anion. The intermediate is a negatively charged intermediate, probably a penta-substituted silicon species.     

三聚氰胺产需现状及市场分析（一）

世界三聚氰胺的总生产能力约为110万t/a,主要集中在西欧、美国、日本等发达国家。世界上最大的三聚氰胺生产商是荷兰DSM公司,生产能力为22.5万t/a。受国际环境的影响,自1997年以来,我国三聚氰胺的生产企业由原来的不足20家猛增至60家,生产能力也由4.5万t/a增加到了19.74万t/a。国际上三聚氰胺的消费结构大致为木材及装饰板占51％,涂料占12％,模塑料、粘合剂、纸处理剂各占10％,其它占7％。我国三聚氰胺的消费量在6万t/a左右,主要集中在木材加工、装饰板、涂料、模塑料和纸张等行业,并且在建筑、涂料和油漆业的应用将不断增加。世界各地的三聚氰胺市场前景不同,东南亚是生产能力增长最快的地区,预计2001～2005年的年均增长率为8%。近年来,世界三聚氰胺的生产能力年均增长速度为13%,而世界三聚氰胺的需求量增长幅度仅为5%～7％,在未来几年中三聚氰胺的全球生产能力将有相当多的过剩;我国三聚氰胺行业有了长足的发展,并呈现出向深层加工和利用发展的趋势,但市场需求在短期内不会有大幅度的增长。随着再建装置的投产,我国三聚氰胺供过于求的形势也将会进一步加剧。     

Electroreduction and oxidation of terephthalaldehyde and the role of hydration

Electroreduction of terephthalaldehyde (benzene-1,4-dicarboxaldehyde) (I) in protic media is complicated by acid-base and hydration-dehydration equilibria. At pH 0-5.5 the diprotonated form of I is reduced in a reversible two-electron step to a diradical-quinonemethide. This species is at pH 1-3 converted into an aldol (4-HOCH₂C₆H₄CHO), which is further reduced at a more negative potential. At pH 5.5-8.5 the monoprotonated form is reduced. The protonated formyl group is reduced first and then, at a more negative potential, the second formyl group in the aldol, formed in the first step, is further reduced. As terephthalaldehyde is in aqueous solutions present in about 15% as a monohydrate, the limiting currents in this pH range are controlled by the hydration-dehydration equilibrium, the establishment of which is acid and base-catalyzed. The reduction of the unprotonated form occurs at pH > 8.5. At pH > 10 addition of OH⁻ ions takes place. The formation of a geminaldiol anion results in a decrease of reduction waves of the aldehyde, but an increase in the oxidation anodic wave of the diol. Dependence of anodic waves on activity of OH⁻ ions indicates a consecutive addition of OH⁻ ions to the two formyl groups. The understanding of the sequence of chemical (protonation, hydration) and electrochemical reaction steps enabled application of changes of polarographic i-E curves with time as an analytical method for following (in real time) concentration changes of the parent compound, its monohydrazones and monoximes as well as dihydrazones and dioximes.     

混联式冷凝器的可视化及传热实验分析

在分析混联式冷凝器中强化凝结传热机理的基础上,选用相同尺寸的平行流冷凝器为基准对比样件,通过高速摄影可视化实验及冷凝器性能测试方法, 对分流孔径为2.5、4.5 mm的两种混联式冷凝器进行可视化分析表明,类似于蒸气喷射流的过热蒸气与气液两相流在集流管中强烈扰动混合,改善了进入下一冷却流道的两相流质量分布的均匀性,扩展了两相流传热区域在混联式冷凝器中的相对占有面积,这使其传热性能比平行流冷凝器可提高9.6%; 同时,制冷系统中的制冷剂质量流量则提高13.43%,为设计更紧凑的空调冷凝器提供了一种新的途径。     

Modelling of binary fluidization of coal and ash and validation using radioactive particle tracking and densitometry

Binary fluidization finds wide application in a variety of gas–solid catalytic and non-catalytic industrial fluidization systems. In the present study, a three-dimensional transient computational fluid dynamics (CFD) model was used to model the binary fluidization of coal and ash in a laboratory-scale cold flow fluidized bed. In parallel, phase velocity measurements using radioactive particle tracking (RPT) and gamma-ray densitometry were performed, which provided a rich database for validation of the CFD model. RPT being a time-resolved Lagrangian technique, it was possible to extract velocity fluctuations and their correlations in addition to the mean velocity profiles. The latter provided additional validation for the CFD model, in addition to the typical validation that is done with time-averaged profiles of phase velocity and volume fraction. The robust validation procedure opens up the possibility of expanding this model to a pilot plant-scale fluidized bed.     

污水污泥肥料化利用的分析与研究

随着世界工业的发展、城市人口的增加,工业废水和生活污水的排放量日益增多,导致污泥的数量迅速增加。为避免污泥产生的二次污染和利用污泥中的有效成分,污泥的处置已经成为全世界关心的问题。在分析了常见的污泥处置方式存在的各种弊端之后,提出污泥的肥料化利用发展方向,指出将稳定化、无害化处理后的污泥作为一种有机肥料使用,将成为我国一种很有应用前景的污泥处置方式。     

苯乙烯的供需现状及发展前景

2005年,全球苯乙烯的总生产能力为2745.0万t/a,总消费量为2434.7万t。预计2010年总生产能力将达到约3786.0万t/a,总消费量将达到约3003.0万t。截止到2006年11月我国苯乙烯的总生产能力为285.5万t/a;2005年产量为125.0万t,消费量为405.0万t。预计2010年我国苯乙烯的总生产能力将达到约600.0万t/a,消费量将达到约580.0万t。针对存在的问题,提出了我国苯乙烯今后的发展建议。     

丙烯酸及其酯的生产和市场

世界主要的丙烯酸生产商为BASF、Rohm＆Haas、Celan-ese、日本触媒,2000年全球丙烯酸的生产能力约为342万t/a,通用型丙烯酸酯的生产能力约为265万t/a,预计2005年全球丙烯酸的生产能力可达396万t/a,丙烯酸酯的生产能力可达307万t/a。国内丙烯酸及其酯的主要生产厂家有3家,即北京东方化工厂、吉联(吉林)化学公司和上海高桥石化丙烯酸厂,2000年我国丙烯酸的生产能力为14.57万t/a,丙烯酸酯的生产能力为14.8万t/a,且主要生产厂家的开工率均在95％-105％,预计2005年国内丙烯酸的生产能力可望达到50万t/a以上,丙烯酸酯的生产能力在45万t/a以上。随着人们生活水平的提高,含高吸水树脂的尿布(裤)将是未来丙烯酸工业发展的最大推动力。但是由于目前国内计划新上和扩建丙烯酸及酯的项目较多,若完全建成则生产能力会在60万-70万t/a以上,供远远大于求,因此希望那些欲上新装置及扩建的厂慎重行事,且应与国际规模接轨,即每套装置达到9万-10万t/a的生产能力。     

TRAIL与导向肽融合基因的克隆、表达及其表达产物的生物学活性

目的获得具有生物学活性的与导向肽融合表达的重组TRAIL蛋白,提高TRAIL对肿瘤细胞的杀伤作用。方法构建TRAIL与导向多肽PEPHC1的融合基因,克隆入质粒pGEM-3zf(-)中进行测序,序列正确后,亚克隆入表达载体pBV220中,转化大肠杆菌DH5α,温度诱导表达。结果42℃诱导4h,融合基因得到了表达,SDS-PAGE表明目的蛋白占菌体总蛋白的15%以上,以包涵体形式存在。经包涵体洗涤、变性、复性,并经离子交换层析柱纯化后可得到融合蛋白PE-TRAIL,经体外试验证明具有生物学活性。结论成功克隆并表达了具有生物学活性的与导向肽融合表达的重组TRAIL蛋白。     

Delignification and Bleaching Response of Earlywood and Latewood

Abstract

The delignification response in cooking and the impact of bleaching on earlywood and latewood were studied. Spruce earlywood and latewood chips were pulped by the kraft process and subsequently treated with one bleaching chemical at a time. In cooking, latewood required a higher alkali charge to reach the same kappa number. No difference in the light absorption coefficient between the different fiber types was observed. After oxygen delignification the earlywood fibers had a higher light absorption coefficient at the same kappa number. The difference in light absorbing material was maintained when bleaching was performed with chlorine dioxide, ozone, and peracetic acid. Hydrogen peroxide decreased the light absorbing structures in the earlywood to the same level as for latewood. The earlywood pulp had a higher brightness at a given kappa number than the latewood. The higher brightness remained through all bleaching operations and was primarily due to a higher light scattering ability.     

Organoleptic and oxidative stability of blends of soybean and peanut oils

A table oil or a salad and cooking oil must serve both as an oil for salad dressings and for cooking potatoes in a deep-fat fryer. Blends of peanut and unhydrogenated soybean oil that have been treated with a metal inactivating agent such as citric acid were scored fairly high by a research taste panel after aging for 4 or 8 days at 60 C. Heating the samples to frying temperature resulted in significantly higher room odor scores for peanut oil than for the blends. Blends of hydrogenated or hydrogenated-winterized soybean oil with peanut oil were generally scored about equal to peanut oil in room odor tests. Potatoes fried in these oils were generally given comparable and not significantly different scores. Presented at AOCS Meeting, Houston, May 1971. Northern Marketing and Nutrition Research Division, ARS, USDA.     

Optical and electronic properties of thin films and solutions of functionalized forms of graphene and related carbon materials

With the advent of many different forms of graphene (in addition to the long standing interest in fullerenes and carbon nanotubes), the characterization of carbon materials and their degree of conjugation is a particularly important topic in carbon science. We report the application of absorption spectroscopy and conductivity measurements to graphene derivatives and related carbon materials. Reduced graphene oxide (RGO) has been widely studied as a promising material for graphene applications because of its processability, and the same considerations apply to graphene functionalized with octadecylamine (ODA). This study utilizes a direct chemical modification of GO with ODA in the presence of dicyclohexylcarbodiimide to partially regenerate the graphene π-conjugation while producing a material (ODA-G) with excellent solubility in organic solvents. We show that the ODA-G exhibits optical absorptions, which are much stronger than those of GO, and comparable to liquid phase exfoliated graphene and reduced graphene oxide; the optical analysis is unified by the development of an analytical relationship between solid state absorption coefficients and solution state extinction coefficients, which allows the direct comparison of the electronic absorption spectroscopy of films and solutions of carbon materials. We further benchmark the regeneration of the graphenic structure in ODA-G with electrical conductivity measurements.     

Thermal and viscoelastic behaviour of copolymers of propene and 1-hexene

Summary The thermal and viscoelastic behaviour of several copolymers of propene and 1-hexene have been studied in a wide range of compositions. The samples were prepared with a Ziegler-Natta catalyst with both internal and external donors. A significant amount of crystallinity has been found for the sample with a comonomer content as high as 19 mol %. The dynamic mechanical results show a considerable decrease of the storage modulus in the copolymers in relation to that of iPP. A single relaxation, corresponding to the glass transition, has been found in all the samples. Only the copolymer with the highest hexene content seems to display the beginning of another relaxation at low temperature.     

Syntheses and reactions of urethanes of cellobiose and cellulose-containing uretdione groups

Urethanes of cellobiose and cellulose-containing uretdione groups are synthesized by the reaction of aliphatic and aromatic diisocyanate uretdiones with the saccharides. The syntheses are performed as a heterogeneous reaction in dimethyl acetamide using dibutyl tin dilaurate as a catalyst, as well as a homogeneous reaction in dimethyl acetamide-lithium chloride. Thus, Semisynthetic prepolymers are formed that offer the reactivity of (blocked) isocyanate groups. To demonstrate their reactivity, ring opening of the uretdiones is performed by the addition of a secondary amine to yield the corresponding ureas.     

Development and application of triglyceride-based polymers and composites

Triglyceride oils derived from plants have been used to synthesize several different monomers for use in structural applications. These monomers have been found to form polymers with a wide range of physical properties. They exhibit tensile moduli in the 1–2 GPa range and glass transition temperatures in the range 70–120 °C, depending on the particular monomer and the resin composition. Composite materials were manufactured utilizing these resins and produced a variety of durable and strong materials. At low glass fiber content (35 wt %), composites produced from acrylated epoxidized soybean oil by resin transfer molding displayed a tensile modulus of 5.2 GPa, a flexural modulus of 9 GPa, a tensile strength of 129 MPa, and flexural strength of 206 MPa. At higher fiber contents (50 wt %) composites produced from acrylated epoxidized soybean oil displayed tensile and compression moduli of 24.8 GPa each, and tensile and compressive strengths of 463.2 and 302.6 MPa, respectively. In addition to glass fibers, natural fibers such as flax and hemp were used. Hemp composites of 20% fiber content displayed a tensile strength of 35 MPa and a tensile modulus of 4.4 GPa. The flexural modulus was ∼2.6 GPa and the flexural strength was in the range 35.7–51.3 MPa, depending on the test conditions. The flax composite materials had tensile and flexural strengths in the ranges 20–30 and 45–65 MPa, respectively. The properties exhibited by both the natural- and synthetic fiber-reinforced composites can be combined through the production of “hybrid” composites. These materials combine the low cost of natural fibers with the high performance of synthetic fibers. Their properties lie between those displayed by the all-glass and all-natural composites. Characterization of the polymer properties also presents opportunities for improvement through genetic engineering technology. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 703–723, 2001     

Characterization and emulsification properties of rhamnolipid and sophorolipid biosurfactants and their applications

Due to their non-toxic nature, biodegradability and production from renewable resources, research has shown an increasing interest in the use of biosurfactants in a wide variety of applications. This paper reviews the characterization of rhamnolipid and sophorolipid biosurfactants based on their hydrophilicity/hydrophobicity and their ability to form microemulsions with a range of oils without additives. The use of the biosurfactants in applications such as detergency and vegetable oil extraction for biodiesel application is also discussed. Rhamnolipid was found to be a hydrophilic surfactant while sophorolipid was found to be very hydrophobic. Therefore, rhamnolipid and sophorolipid biosurfactants in mixtures showed robust performance in these applications.     

三聚氰胺与尿素联产工艺及技术改造

河南省中原大化集团有限责任公司采用联产技术对三聚氰胺尾气进行回收,并对原尿素装置进行改造,新增了11万t/a尿素生产装置,并配套增设了尿素水解装置、OAT水解装置、碳铵液回收装置和尿素熔化装置。各装置彼此联系,又相对独立,充分发挥了尿素装置和三聚氰胺装置的联产优势,降低了三聚氰胺的生产成本,确保了污染物的达标排放。     

Thermal and crystallization behavior of alloys of polyphenylene sulfide and high-density polyethylene

The thermal and crystallization behavior of alloys of two semicrystalline thermoplastics, namely, polyphenylene sulfide (PPS) and high-density polyethylene (HDPE) were studied by differential scanning calorimetry (DSC). The presence of a second component in the alloy was found to influence the nonisothermal crystallization process of both the component polymers. The crystallization temperature of PPS in the DSC cooling scan is significantly affected, whereas there is little variation in case of HDPE in the composition range studied. The morphological changes observed in both PPS and HDPE are similar. These include larger crystallite size, a narrower crystallite size distribution, and a lower degree of crystallinity in the alloys as compared to the homopolymers. The isothermal crystallization of the component polymers in the alloys is significantly different from that of the homopolymer. The composition dependence of the overall rate of isothermal crystallization is explained in terms of the competing processes of nucleation and crystal growth. The results show that blending of a high melting polymer with a low melting polymer accelerates the crystallization of the high melting polymer, even at low levels of about 10% of the lower melting component.     

Mixtures of anionic and cationic surfactants with single and twin head groups: Solubilization and adsolubilization of styrene and ethylcyclohexane

Mixtures of anionic and cationic surfactants with single and twin head groups were used to solubilized styrene and ethylcyclohexane into mixed micelles and adsolubilize them into mixed admicelles on silica and alumina surfaces. Two combinations of anionic and cationic surfactants were studied: (i) a single-head anionic surfactant, sodium dodecyl sulfate (SDS), with a twin-head cationic surfactant, pentamethyl-octadecyl-1,3-propane diammonium dichloride (PODD), and (ii) a twin-head anionic surfactant, sodium hexadecyl-diphenyloxide disulfonate (SHDPDS), with a single-head cationic surfactant, dodecylpyridinium chloride (DPCl). Mixtures of SDS/PODD showed solubilization synergism (increased oil solubilization capacity) when mixed at a molar ratio of 1∶3; however, the SHD-PDS/DPCl mixture at a ratio of 3∶1 did not show solubilization enhancement over SHDPDS alone. Adsolubilization studies of SDS/PODD (enriched in PODD) adsorbed on negatively charged silica and SHDPDS/DPCl adsorbed on positively charged alumina showed that while mixtures of anionic and cationic surfactants had little effect on the adsolubilization of styrene, the adsolubilization of ethylcyclohexane was greater in mixed SHPDS/DPCl systems than for SHDPDS alone. Finally, it was concluded that whereas mixing anionic and cationic surfactants with single and double head groups can improve the solubilization capacity of micelles or admicelles, the magnitude of the solubilization enhancement depends on the molecular structure of the surfactant and the ratio of anionic surfactant to cationic surfactant in the micelle or admicelle.