双马来酰亚胺／氰酸酯树脂的研究进展

双马来酰亚胺树脂／氰酸酯树脂（BT树脂）是一种高性能热固性树脂,综合了氰酸酯树脂与双马来酰亚胺树脂的优良性能,应用领域广泛。阐述了BT树脂的固化机理及现有的改性研究思路。并且对我国BT树脂的发展进行了展望。     

植物油基环保树脂的研究进展

概述了植物油基树脂制备方法与原理,讨论了植物油基环保树脂的优势及存在的缺陷。此外,还介绍了植物油基环保树脂在零溶剂或低溶剂树脂、高固体分树脂、水性树脂以及紫外光固化树脂方面的最新研究成果,并分析了植物油基环保型树脂的发展趋势。     

特种聚氯乙烯树脂生产概况

简述了国内外主要特种聚氯乙烯树脂(包括高聚合度PVC树脂、消光PVC树脂、PVC掺混树脂、氯乙烯一醋酸乙烯共聚树脂和氯化PVC树脂)的生产情况。并列举了主要特种PVC树脂的生产厂商、牌号和技术规格。     

国内双马来酰亚胺树脂改性研究进展

目前双马来酰亚胺(BMI)树脂作为一种高性能树脂基体应用广泛。文中概述了国内二元胺改性BMI树脂、烯丙基化合物改性BMI树脂、热塑性树脂改性BMI树脂、弹性体改性BMI树脂及其他一些BMI树脂的改性方法。     

丙烯酸树脂现状及其在海洋防污涂料中的应用

阐述了丙烯酸树脂的发展历程和研究现状。按照成膜方式、分散所用溶剂和树脂用途对丙烯酸树脂进行分类。详细介绍了丙烯酸树脂在海洋防污涂料中的应用,其中包括无锡自抛光丙烯酸锌/铜树脂涂料、有机硅改性丙烯酸树脂防污涂料和有机氟改性丙烯酸树脂防污涂料。最后对丙烯酸树脂研究方向进行了展望。     

聚氯乙烯树脂行业现状、发展趋势及建议

综述了聚氯乙烯树脂的生产现状,分析了聚氯乙烯树脂目前的需求状况,阐述了聚氯乙烯树脂的发展趋势;预测了聚氯乙烯树脂的未来需求情况,并提出了聚氯乙烯树脂发展的几点建议。     

高性能树脂基体在航空航天复合材料上的应用

本文描述了用于航空航天复合材料的热固性基体树脂,主要介绍了环氧树脂、双马来酰亚胺树脂、聚酰亚胺树脂、氰酸酯树脂、聚芳基乙炔树脂的性能及运用,评述了其发展趋势。     

改性沥青树脂及其复合材料的制备及相关性能

以煤沥青为原料、三聚甲醛为交联剂,在对甲苯磺酸的催化作用下合成了沥青树脂（COPNA树脂）,通过添加酚醛树脂对其进行了改性;分别以沥青树脂和改性树脂为原料,与石墨混合制备了复合材料。考察了酚醛树脂含量对改性树脂的残炭率、甲苯不溶物含量、喹啉不溶物含量、p树脂含量的影响,以及树脂含量对复合材料的电阻率,肖氏硬度的影响;采用FT—IR和H—NMR研究其反应机理;采用TG研究了沥青树脂和改性树脂的热行为。研究表明,酚醛树脂与沥青树脂可以在一定比例范围内进行复配,在加热混合过程中酚醛树脂与沥青树脂发生化学反应,提高了沥青树脂的耐热性。经酚醛树脂改性的沥青树脂具有更高残炭率、更高β树脂含量和更好耐热性。改性后的树脂复合材料具有更高的电阻率、更高的肖氏硬度和更高的耐磨性。     

高性能氟化聚氨酯弹性树脂

简述了氟化聚氨酯弹性树脂的制备工艺，列举了弹性树脂的主要性能。讨论了氟树脂、异氰酸酯等凶素埘树脂性能的影响，并对树脂的结构和性能进行了分析与表征。     

国内特种PVC树脂的开发及市场需求

介绍了特种PVC树脂的分类和特征,重点阐述了高聚合度PVC树脂、特种PVC糊树脂、氯醋树脂、CPVC树脂的技术开发、市场需求及消费情况。     

影响负重轮橡胶材料压缩疲劳生热性能因素的研究

主要讨论了橡胶种类、炭黑种类及白炭黑对负重轮橡胶材料压缩疲劳生热性能的影响。结果表明．并用5～10份顺丁橡胶对胶料压缩疲劳生热性能没有影响;添加结构程度相近、粒径不同的炭黑对压缩疲劳生热性能有影响;使用10～15份白炭黑可提高压缩疲劳生热性能。     

Modeling of bubble rise in a liquid subject to surface mineralization

A mathematical model of a bubble rise in a liquid according to the degree of the surface mineralization (filling) of the particles was developed. The comparisons of the calculation results for the speed of bubble rise with empirical formulas were given. The question of differential equation hardness for bubble motion was investigated. The effect of changes in bubble size during the rise on the speed and time of bubble rise was studied. The results of numerical experiments were analyzed.     

热油泵机械密封失效分析与对策

通过故障模式及影响分析方法,并采集实际机械密封失效数据进行验证,采用有限元建模分析不同转速、不同压力、不同材料下机械密封的温升情况。结果表明,温升异常是机械密封失效的最主要的原因,转速和压力与温升成线性正比关系;Si C作为密封材料时,温升较为理想。结合实际选型、安装、运行工况提出了改善机械密封的措施。     

蓄热式水煤浆气化炉烧嘴的方案研究

传统的水煤浆气化炉的启动运行,需要大量的点火燃料气进行预热,预热过程中需要保持炉膛的负压(或微正压)状态,无法使气化炉的升温和升压同时进行。提出了一种新的蓄热式水煤浆气化炉烧嘴理念,在对传统水煤浆和氧气供应系统进行必要改动的前提下,能够使水煤浆气化炉在冷态情况下实现同时升温和升压,可节约点火燃料气的消耗和开车用时。分析了新理念的理论基础,介绍了新理念具体实施的燃料气加热方案和燃气发生器方案,并对方案中的有关参数进行了仿真模拟。     

Heat evolution of high-volume fly ash concrete

In this paper, the results of a laboratory investigation conducted with heat evolution of high-volume fly ash (HVFA) concrete are presented. Heat evolution of concrete was studied by measuring the temperature increase in concrete under adiabatic curing condition. Characteristic of heat evolution of fly ash concrete was found to be strongly dependent on the replacement level of fly ash and dosage of superplasticizer used to maintain workability. It was also found that using fly ash as cement replacement resulted in a reduction on the maximum temperature rise. Increasing the replacement level of fly ash caused lower temperature rise in concrete. Superplasticizer caused a delay in peak temperature rise time; this is taken as an indicator that high-dosage superplasticizer used in concrete caused retardation in hydration of cement. Concretes having similar ingredients showed similar peak temperature rise whether they are superplasticized or not.     

Pultrusion die pressure response to changes in die inlet geometry

Pultrusion is a process of manufacturing composites that requires a high resin pressure rise in the tapered die inlet region. A sufficiently high pressure rise is important for a good quality pultruded product, thereby necessitating a study of the mechanisms affecting the die inlet pressure rise. Various process control parameters affect the resin pressure rise in the die inlet. The geometry of the tapered die inlet region can have a significant effect on the pressure rise in the pultrusion die. In this study a finite element model was developed to predict this pressure rise as a function of the tapered die inlet geometry. The composite matrix being pultruded was modeled on the assumptions of Darcy's laws for flow in porous media. A Galerkin's weighted residual based finite element technique was used to solve the governing equations. The pressure rise in the tapered inlet region of the die, as well as in the straight portion of the die, is predicted by this finite element model. Circular, parabolic, and wedge shaped die inlets have been modeled to compare their shapes on the resin pressure rise in the pultrusion die. Different angles for wedge shapes, different radii for circular shapes, and different foci for parabolic shapes were modeled to predict the influence of varying key geometrical parameters for each die inlet contour on pressure rise. The finite element model developed provides insight as to how to design the die inlet to produce a suitable pressure rise in the pultrusion die inlet.     

Temperature rise during anodic oxidation of zirconium

The temperature rise in the anodic oxide during its formation on zirconium has been measured using the anodizing specimen as a resistance thermometer. The temperature rise in the oxide formed on strip samples was reduced by electrolyte stirring. The temperature of an anodized wire was found to be less than that of the anodized strip under otherwise similar conditions. The temperature rise is shown to depend on the balance between the rate of heat generation in the oxide and the rate at which it is conducted to the surrounding electrolyte. This latter factor changes with geometry and with stirring of the solution.     

Investigation of trajectory and rise velocity of loaded and bare single bubbles in flotation process using video processing technique

In flotation, among the key parameters that dictate the hydrodynamic characteristics are bubble rising velocity and trajectory. This study aims to investigate the trajectory and rise velocity of loaded and bare bubbles using an experimental setup and video processing technique. After acquiring the videos of rising bubbles, using the background subtraction algorithm, bubbles were detected and their rise velocity and trajectory were determined with regard to the changes in the coordinates of bubbles’ centers. It was shown that bare bubbles have a zigzag trajectory, while for loaded bubbles the trajectory was close to the straight vertical path. In addition, with increasing bubble size, the rise velocity and the deviation from the straight path increase.     

Pressure effects on temperature measurement of polymer melt

Polymer melt temperature dependence on the pressure have been measured directly by a novel temperature sensor in a versatile test rig which was developed to measure melt temperature profiles in the injection moulding processing. The results show that the melt temperature increases linearly with the pressure applied to it. The larger the initial bulk melt temperature, the larger the temperature rise for a particle rise in pressure. The temperature rise resulting from compression is also related to the structure properties of the polymer.     

On-line density and crystallinity of polyethylene terephthalate during melt spinning

The density and crystallinity of polyester fiber were measured on the moving threadline during the melt spinning process. The density was calculated by applying the continuity equation at points along the length of the threadline. Experimental inputs to the equation included paralle, on-line measurements of fiber diameter, fiber velocity, polymer mass flowrate, fiber temperature, and fiber birefringence. When spinning speeds exceeded 4500 m/min, a distinct rise in density occurred along the threadline. This rise corresponded with the rise in birefringence.