苯酚产需现状及市场分析

2000年世界苯酚总生产能力约为740万t/a,总消费量为636万t/a,主要用于生产双酚A和酚醛树脂。预计世界苯酚需求将以每年4％-5％的速度增长。美国、西欧和日本是世界上3个最主要的苯酚生产国家和地区,北美地区的总生产能力为300万t/a,占世界总产能的40.6％,而德国酚化学公司是世界最大的苯酚生产厂家,其产能为145万t/a,占世界总产能的19.6％。2000年,我国有30家苯酚生产企业,总生产能力为28.9万t/a,总产量为24.94万t/a,主要用于酚醛树脂和水杨酸的生产。在1996-2000年间,中国大陆苯酚的净进口量分别为9.79万t、6.22万t、3.72万t、7.38万t和9.69万t,从2000年9月开始,从中国台湾的苯酚进口量增长很快。为增强市场竞争力,中国大陆苯酚生产企业应提高单套装置的生产能力,采用一体化生产模式。     

FR-4敷铜板专用四溴双酚A环氧树脂生产工艺优化

介绍了FR 4敷铜板专用CYD 5 2 1 A 80四溴双酚A环氧树脂的性能、生产原理、工艺流程及生产工艺的再优化 ,使产品色度、粘度指标均达到FR 4敷铜板的高标准要求。产品质量稳定 ,为CYD 5 2 1 A 80产品国产化奠定了技术基础。     

双酚A苯并恶嗪一环氧树脂基印制电路基板的研究

采用双酚A苯并恶嗪与环氧树脂共混改性制得胶液,经浸渍玻璃布、烘焙、压制得到了一系列玻璃布覆铜板基板其中含溴型基板的玻璃化转变温度为145.2℃,加强耐热性在300s以上,常温下表面电阻率和体积电阻率分别为1.51×1014Ω、5 75×1014Ω@m,无溴型基板玻璃化转变温度为160.3 ℃,加强耐热性在300 s以上.常温下表面电阻率和体积电阻率分别为1.91×1013Ω、5.01×1013Ω@m,覆铜板的耐浸焊性能优异,达到60s以上     

Use of organosolv lignin in phenol-formaldehyde resins for particleboard production: II. Particleboard production and properties

The objective of this work was to demonstrate the utility of lignin-based resins designed for application as an adhesive in the production of particleboard. Bond qualities of lignin-phenol-formaldehyde resins, phenolated-lignin-formaldehyde resins and commercial phenol-formaldehyde (PF-com) resin were assessed by using an automatic bonding evaluation system, prior to production of particleboards. In order to evaluate the quality of lignin-based resins, particleboards were produced and physical and mechanical properties were investigated. These physical properties included internal bond, modules of rupture and modulus of elasticity. Thickness swell and water absorption properties of particleboards bonded with lignin-based resins were also determined. The lignin-based resins have been reported previously in Part I of this study. The results showed that particleboards bonded with phenolated-lignin formaldehyde resins (up to 30% lignin content) exhibited similar physical and mechanical properties when compared to particleboards bonded with PF-com. The work has indicated that phenolated-lignin formaldehyde resins (up to 30% substitution level) can be used successfully as a wood adhesive for constructing particleboard. The performance of these panels is comparable to those of boards made using PF-com resin.     

Kinetic investigation of the carbothermal reduction of an Iranian clay

The kinetics of the carbothermal reduction of clay under argon atmosphere has been investigated by the X-ray diffraction method. The clay-carbon (excess) mixture was formed into 2 cm diameter disks of different thicknesses. Experimental data evidences the significant effect of sample thickness on the reaction rate at 1400 °C. Decreasing thickness promotes mullite dissociation and formation of SiC and alumina powders. Mathematical modeling of the reaction system showed the gas diffusion in the Knudsen regime through the pellet to be the rate controlling step. Diffusivity of CO and reacted core tortuosity factor have been calculated.     

Preparation of PAN-zeolite 4A composite ion exchanger and its uptake behavior for Sr and Cs ions in acid solution

A PAN-4A composite ion exchanger containing about 80% 4A powder was prepared to remove strontium and cesium ions from acidic solution. The SEM image of the fracture of composite bead showed that zeolite 4A powder was dispersed homogenously and the pores were well formed. The mean pore size of composite bead was 0.14 μm and its porosity was about 74%, which is much higher in comparison with the existing inorganic adsorbent beads. The acid and radiation stability tests showed that PAN-4A was stable against acid solution higher than pH 2 and radiation dose less than 1.89×10⁸ rad, respectively. Ion exchange tests showed that the PAN-4A was selective for Sr ion. The distribution coefficients of PAN-4A for Sr and Cs ions at pH 2 were 2×10⁴ mL/g and 280 mL/g, respectively. The ion exchange capacities (q_s) of PAN-4A for Sr and Cs ions at pH 2, which are modeled by Dubinin-Polanyi equation, were 3.92 meq/g and 2.47 meq/g, respectively.     

DRYING KINETICS DERIVED FROM DIFFUSION EQUATION WITH FLUX-TYPE BOUNDARY CONDITIONS

A novel approach to drying of both hygroscopic and non-hygroscopic capillary - porous materials is presented. The equations for drying kinetics are obtained, based on the analytical solution of the differential equation of diffusion with a boundary condition in the form of the flux. Theoretical drying curves generated form the model solution compare well with experimental literature data for drying of materials with different sorption properties exemplified by wool bobbins, brick slabs and corn kernels.     

COMBINED CONVECTIVE-MICROWAVE DRYING OF AGAR GELS: INFLUENCE OF MICROWAVE POWER ON DRYING KINETICS

The use of microwave energy in the drying of deformable material such as gel considerably reduces drying time and enables the control of retraction in the sample. A further advantage is that no hot spots are produced, allowing a dry product of superior quality to be obtained.The aim of this work has been to determine the kinetics of the convective-microwave drying process of agar gel plates. For this purpose, we developed a pilot closed loop, computer-controlled apparatus of convective-microwave drying, that enables the drying air conditions to be changed and the microwave power to be supplied over a wide value range. The equipment also records the sample surface temperature by means of an infrared thermometer. The drying curves obtained for plane geometry present four different drying phases: an initial phase where a rapid increase in the drying rate and in the surface temperature can be observed, as well as a constant rate phase that ends in the so-called convective critical moisture content, a first falling rate phase that concludes in the microwave critical moisture point, and finally a second falling rate phase. Combined convective-microwave drying enables a considerable reduction in drying time compared to convective drying, the time required being inversely proportional to the microwave power supplied. The empirical equation that best represents the kinetics is of the Page type. The absorbed volumetric power in terms of the moisture content was experimentally estimated, with the experimental data fitting an empirical equation.     

采用一批细胞基质同时收获甲肝和麻疹病毒

目的 采用一批细胞基质同时收获甲肝和麻疹病毒。方法 应用甲肝 L-A-1株和麻疹 27D3株,间隔3周先后感染同一批人胚肺二倍体细胞2BS株,待两种病毒同时达到增殖高峰期时收获病毒液（以下简称HAM）,并分别进行病毒滴定、特异性检查、猴体安全性和免疫效果试验。结果HAM的甲肝和麻疹病毒滴度与同批单价甲肝和麻疹疫苗病毒滴度,差异均无显著意义。结论 该方法用于制备甲肝-麻疹联合疫苗,操作简便,省时省力,并可显著降低疫苗生产成本。