pH值对AlN粉末水解产物的影响

通过测定500nm的氮化铝粉末在不同pH值下的水解行为,利用XRD、SEM和TEM分析研究了氮化铝粉末的水解产物。结果表明,在pH=12环境下水解产物为纳米纤维状,在Ph=7环境下水解产物为短棒状,在pH=5环境下水解受到抑制。XDR表明,在80℃下水解时,AlN粉末的水解产物为AlOOH。SEM和TEM表明,在pH=5环境AlN形成了一个保护层,在pH=12环境下时,氨水会使水解产物形成团聚。     

聚合物包覆硫黄的制备及其在子午线轮胎胎面胶中的应用

分别以乙烯基树脂和改性聚氨酯为包覆壁材制备4种聚合物包覆硫黄产品,对其进行扫描电子显微镜分析,并研究其在轮胎胎面胶中的应用。结果表明:硫黄表面有明显的包覆层;用于胎面胶配方时采用聚合物包覆硫黄的混炼胶的加工性能、硫化特性以及硫化胶的物理性能与采用不溶性硫黄IS-7020的胶料相当。     

重油催化裂化沉降器结焦的研究进展

分析了重油催化裂化 (RFCC)沉降器结焦的影响因素和机理。反应油气中含有催化剂颗粒以及油气中重组分的冷凝是沉降器结焦的物理因素 ,而重芳烃、胶质、沥青质的高温缩合和油气中烯烃和二烯烃的环化聚合反应则是沉降器结焦的化学因素。通过对液相重组分高温缩合机理、相分离生焦机理和自由基反应机理等沉降器结焦机理的分析 ,认为沉降器中油气的气、液相分别遵循不同的结焦历程 ,抑制沉降器结焦的关键在于抑制反应油气中重组分的冷凝和缩短反应油气的停留时间     

Practical and theoretical molecular weights in polyaddition reactions of ethylene and propylene oxide

The addition reactions of ethylene oxide and/or propylene oxide catalyzed by KOH and initiated with compounds containing free hydroxyls are followed by secondary reactions which vary the expected molecular weight. By using ethylene oxide, diols are formed and by using propylene oxide, both diols and unsaturated monofunctional compounds are formed. These products are usually characterized by their hydroxyl number. The average molecular weight is found by taking into consideration the starter functionality only. There are often some behavioral differences among similar products owing to the different quantity and chain length of the secondary products contained therein. The secondary products are analyzed and the quantity of the secondary products were determined from the hydroxyl number values and from the unsaturation of reagents and products. In the case of monofunctional adducts using the calculation method, the results have been experimentally confirmed.     

Review of European legislation on vegetable protein in meat products

A review of the legislation concerning the use of vegetable protein products in meat products is given for 15 West European countries. Existing requirements in these countries concerning composition and labeling of meat products containing vegetable protein are compared, and it is shown that wide divergencies exist. Some countries explicitly forbid addition of vegetable protein to meat products, other countries permit such additions in specified amounts to specific meat products and others again do not set limitations on either the amount of vegetable protein or the type of meat products to which they may be added. Labeling provisions, likewise, vary to a great extent. These differences are linked to the regulations on meat products in the various countries which often reflect a strong national tradition. In most of the countries no general approach to regulating use of vegetable proteins in meat products has yet been taken. But a few of the countries are formulating such a policy, and the possible outcome of these ongoing deliberations is outlined.     

Economic considerations on the use of vegetable proteins in Danish meat products

Use of vegetable proteins in meat products in Denmark is discussed with special reference to economy. Aspects of price vs. quality also are discussed, and performance criteria in the evaluation of vegetable protein products are proposed. Examples are given of recipe optimization with soy protein products, and finally the market perspectives are outlined. It is emphasized that no conflict is seen between the use of vegetable proteins in meat products and agricultural or consumer interests.     

口腔护理品的最新进展

介绍了口腔护理品原料的功效及组分,论述了口腔护理品发展的最新趋势,指出增白牙膏、疗效型牙膏及口气清新产品依然是口腔护理品销售市场的亮点,牙膏市场也逐步从卫生品向化妆品转变,多功能、方便及有效性依然是消费者追求的目标.     

Ozonation Reaction Patterns of Alcohols and Aliphatic Amines

Aqueous solution of alcohols and aliphatic amines are oxydized with ozonated oxygen. Formation of aldehydes, ketones, acids and peroxydic products is evidenced in the case of alcohols in concentrated solution. Hydroxylamine oxime and amide are also identified in the case of amines. The formation of condensation products from the amine or the intermediate amide is also seen. In diluted solution, the compounds disappear and certain ozonation products are formed but not the products of condensation.     

我国中微量元素肥料产业发展现状

根据国家化肥质量监督检验中心(北京)肥料登记信息,我国以中微量元素肥料为主要成分的登记产品已经达到1 352个,共有969家企业生产中微量元素肥料,产地主要在山东等地。目前产品类型以微量元素水溶肥为主,占中微量元素肥料产品总数的92%,并且呈现快速发展趋势。微量元素水溶肥产品98%是复合型,以Zn、Mn、B等组合为主。全国中微量元素肥料涉及到的作物已经达到59种之多,基本覆盖了我国主要作物种类。     

Origin of certain heterocyclic compounds from depolymerization of lignite

The origins of products observed in the acid-catalysed phenolic depolymerization of a lignite are discussed. The isolation of ¹⁴C-labelled xanthene and 9-arylxanthenes from the use of 1-¹⁴C-phenol in lignite depolymerization reactions demonstrates the solvent origins of aromatic portions of these products. Methylene-, methine-, and ethylene-bridged aromatic products were identified by gas chromatography—mass spectrometry (GCMS) techniques, demonstrating a close similarity to products from the depolymerization of brown coals and lignites. Reactions of model triarylmethane compounds under depolymerization conditions demonstrated the facile conversion of triarylmethine structures to diarylmethane structures, indicating ambiguity in the simple interpretation of diarylmethane products as having derived from diarylmethane functional groups in coal. Alternative mechanistic pathways to observed products are presented.     

蜡产品市场供需现状分析

蜡类产品的应用非常广泛,在许多家庭用品和工业用品中都能经常遇到.石油蜡仍是目前蜡市场的主流产品,但使用量在逐年降低.中国是全球最大的石油蜡生产国,全球大约有1/3的石油蜡都产自中国.聚烯烃蜡在美国和欧洲市场的应用发展更为迅速,具有更好的市场前景,值得关注.     

Decomposition products of PVC for studies of fires

Approximately seventy-five organic materials have been detected by gas chromatography in the thermal decomposition products of PVC and are shown by mass spectrometry and retention studies to consist mainly of aromatic and aliphatic hydrocarbons. Weight-loss experiments and time-resolved chromatography indicate that these products are formed mainly during dehydrochlorination. The products are modified by the presence of oxygen but no oxygenated organic species have been detected. Experiments to specifically monitor the production of phosgene from the decomposition of both a rigid PVC sheet and a PVC polymer in air are recorded. Phosgene has not been detected and direct seeding techniques have been used to investigate the detection limits of this material. PVC is known to release the toxic gases, carbon monoxide and hydrogen chloride, when involved in fires. It is shown that the minor products, including phosgene, make little or no contribution to the overall toxicity of the decomposition products.     

Pyrolysis of benzenethiol

Flow pyrolysis of benzenethiol at 700 °C or vacuum pyrolysis of benzenethiol at 800 °C yields benzene, diphenyl sulphide and diphenyl disulphide as the major products. Dibenzothiophene, biphenyl, thianthrene and diphenyl trisulphide are minor products. Co-pyrolysis of benzene-d₆ and natural isotopic abundance benzenethiol yields deuterated and non-deuterated products, indicating that the product-forming sequence is initiated by phenyl radical formation. The phenyl radicals abstract hydrogen atoms from benzenethiol to yield benzene and phenylthio radicals. Coupling of phenylthio radicals yields diphenyl disulphide. Diphenyl sulphide and the minor products are diphenyl disulphide pyrolysis products.     

1,1,1-三氯乙烷的稳定剂配方研究

通过试验提出了2组有使用价值的稳定剂配方组成。结果表明,研究取得了预期效果,特别配方(Ⅱ)使用后,产品各方面特性和旭化成产品的指标相似,稳定后产品能被用户广泛接受。     

天然个人护理品趋势

论述了各种天然成分在化妆品中的应用。随着消费者对于保持身体和精神健康方面的兴趣越来越大,直接导致了天然个人护理品市场的大幅增长。指出,随着有机食品与健康产品的大量涌现,天然个人护理品市场快速发展,护肤、护发和化妆品类产品比以往更受欢迎。由于污染问题的严重、全球变暖的加剧以及各种疾病的流行,迫使消费者们去寻找一种更天然、环境更友好的替代品。越来越多的消费者已经开始注意各种天然产品所带来的种种好处,因而,天然产品的需求也呈现出稳步增长的态势。     

Use of soy products in dairy product replacement

Soy protein products can be used to replace or supplement dairy products in many food products. Several such applications are described.     

影响镁铝碳制品高温性能的因素

研究了结合剂种类、石墨和特级高铝矾土熟料加入量对镁铝碳 (MAC)制品高温性能的影响。结果表明 :结合剂的性能显著影响MAC制品的高温性能 ,树脂类结合剂结合试样的高温性能优于水玻璃结合的 ;随着C含量增加 ,MAC制品的高温抗折强度降低 ,但抗渣和抗热震性能提高 ;在一定的Al2 O3含量范围内 ,MAC制品的高温力学性能优于镁碳砖 ,主要原因是其基质中生成的致密晶间尖晶石提高了基质中高熔点晶体间的直接结合程度。     

环己烯下游产品的研究进展

环己烯下游产品如环氧环己烷、己二酸、环己醇、环己二醇、环己烯酮和环己酮等是重要的有机合成中间体,开发环己烯下游产品的研究具有重要意义.本文阐述了一些有工业开发前景产品的合成方法、路线及其存在的缺陷,并对产品的研究方向和发展前景进行了探讨.     

Thermal oxidation of polypropylene close to industrial processing conditions

Thermal oxidation of isotactic polypropylene (PP) at 220 and 280°C in air was studied. Gas chromatography–mass spectrometric analysis was used to separate and identify the volatile products of PP oxidation. Twenty-three products were identified and 15 substances were quantified. The aldehydes are the principal products formed, followed by ketones, acids, and alcohols. The main organic product quantified was acetaldehyde. The volatile organic products formed constitute about 3% of the amount of water formed. The relative amounts of the most volatile products formed in the range 220–280°C are practically independent on the temperature of oxidation. The mechanism of formation on the oxidation products is discussed.     

Deacetylation of β‐chitin. I. Influence of the deacetylation conditions

The influences of the deacetylation temperature, deacetylation time, and NaOH concentration on the degree of deacetylation (DD) of deacetylated products prepared from β‐chitin are discussed. The DD values of deacetylated products are related to the ratio of the signal intensities of methyl on acetyl groups and the first anomeric carbon, which are obtained from ¹³C‐NMR spectra. The results show that the DD values of deacetylated product increase as the NaOH concentration, deacetylation time, or deacetylation temperature increases. The thermal properties, chemical structures, and crystalline characteristic of deacetylated products are significantly related to their DD values. Differential scanning calorimetry shows that the peak temperature is slightly increased as the DD values of deacetylated products of β‐chitin increase. Thermogravimetric analysis shows that the thermal degradation onset temperature of deacetylated products decreases as the DD values increase. Fourier transform infrared spectra show that the intensity of a specific absorption peak of ? NH₂ in deacetylated products significantly increases as DD increases. X‐ray diffraction patterns of deacetylated products with DD values of 17.5 and 44.7% have three significant diffraction peaks. However, there are only two diffraction peaks found in products with higher DD values of 76.5 and 94.7%. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2416–2422, 2004