制浆造纸工业用消泡剂的开发及应用进展

制浆造纸工业生产过程中不可避免会产生泡沫,泡沫控制不当会严重影响制浆造纸工艺条件的执行以及设备的正常运转,导致产品产量和质量降低,而控制泡沫最直接有效的措施是添加合适的消泡剂.该文介绍了制浆造纸工业生产中泡沫的产生和稳定机理,泡沫对制浆造纸工业生产过程和产品质量的影响,并针对制浆造纸生产中制浆、抄纸、涂布和脱墨等工段泡沫特性和消泡要求,综述了制浆造纸用消泡剂的发展历程、各工段消泡剂种类和性质,介绍了消泡剂的研制开发和实际应用成本及使用效果等,并对制浆造纸用消泡剂的发展进行了展望.     

Rheological properties and foam processibility of precured EPDM

EPDM foam was prepared by dynamically vulcanizing EPDM compound in a HAAKE rheometer firstly, then mixing the partially precured EPDM compound with a blowing agent and a sulfur vulcanizing system on a two roll mill. The compound was extruded through a cold feed extruder, and the extrudate was foamed in a circulating hot air oven. EPDM compound was vulcanized partly in the HAAKE rheometer, the final torque increases with increasing sulfur content. Rheological measurement shows the dynamic storage modulus, the loss modulus, and the complex viscosity of precured EPDM compound increase with increasing sulfur content. Then the partially precured EPDM compound was compounded with a blowing agent and a sulfur vulcanizing systems, Rheometric measurement shows that the rate of vulcanization of partially precured EPDM compound is not affected by the precure. The blowing results show that the foam processibility could be improved and the expansion ratio increases in the same processing condition for optimum partially precured EPDM compound, which indicates the optimum crosslink density for EPDM could enhance the efficiency of blowing agent AC. SEM shows that the foam articles have a closed‐cell structure with few open cells, and the large cells inlay among the small cells. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3387–3394, 2006     

酚醛树脂改性聚氨酯硬质泡沫塑料的研究

在多元醇中掺入甲阶酚醛树脂，与异氰酸酯反应，可以获得具有PF阻燃性和PU绝热性能的PF／PU共聚硬质泡沫塑料。介绍了甲阶酚醛树脂制备方法，并对其合成工艺、反应条件控制等进行了较详尽的探讨。     

挤出机各段温度对开孔型橡塑共混材料性能的影响

研究开孔型橡塑共混材料在不同挤出加工工艺中结构形态及力学性能的变化规律。结果表明，挤出机的机头温度应稍高于发泡剂的分解温度，均化段温度要设在发泡剂分解温度区的低温段，在挤出加工工艺中，要特别注意挤出机均化段温度及机头温度的设定，温度设定不好会使发泡剂无法发挥作用。     

Hydraulic resistance of rigid polyurethane foams. II. Effect of variation of surfactant,water, and nucleating agent concentrations on foam structure and properties

Hydraulic resistance of rigid polyurethane foams to penetration by water at high pressures is studied in this work in the context of buoyancy applications. Micron sized silica particles are used as nucleating agents. The effect of the variation of the concentrations of the surfactant, water, and nucleating agent on cell structure, closed cell content, and compressive modulus, is examined. Foams have densities in the range of 145 to 165 kg/m³. At a particular water concentration, with increase in the concentration of the surfactant, the window area of the cells becomes smaller and the hydraulic resistance of the foam increases. A cell window is the lamella of the foam material that separates two adjacent cells. With increase in the concentration of water keeping surfactant concentration constant, the average window area remains almost the same but the cell window area distribution becomes wider and the hydraulic resistance of the foams decreases. Foams made with silica have smaller cell windows but lower hydraulic resistance than that of the foams made without silica. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2830–2837, 2004     

涤纶废产物用于制备聚氨酯泡沫塑料

将涤纶废产物用二甘醇和三元醇经酯基转移合成齐聚酯多元醇，并用其制备聚氨酯硬质泡沫塑料。该泡沫塑料具有良好的力学性能，且随着齐聚酯多元醇平均官能度的影响，力学性能随之提高；由于齐聚酯多元醇中芳香族基团含量高，泡沫塑料的铖一明显高于普通聚氨酯泡沫塑料。     

城市异形排涝通道消能防冲新技术

该文针对感潮河段魁岐排涝二站?型复杂流道的不利冲刷问题,通过建立整体水工模型,研究城市异形排涝通道消能防冲新技术,提出导流坎、消力坎和消力墩联合消能防冲技术,探索其在宽幅水位变化、多工程交替运行及通航情况下的适应能力,并给出水力设计方法。研究表明,联合消能工对复杂工况适应良好,能有效解决异形排涝通道的消能防冲问题。     

热塑性硬质聚氨酯泡沫在汽车顶内饰中的应用

概述了汽车顶内饰用热塑性聚氨酯硬质泡沫塑料进展状况，介绍了硬泡及顶内饰成型方法，对影响该硬泡性能的一些因素进行了讨论。指出该顶内饰已批量生产。     

杭州市城西地区洪水出路研究

杭州市城西地区地势低洼,上承山水,下受杭嘉湖平原河流水位顶托,为易受洪涝灾害地区。以抵挡2007年"罗莎"台风洪水为目标,根据城西地区水系分布、城市布局,初步提出了洪水外排、湿地调蓄、建圩挡水的排涝布局及10种洪水出路方案。对10个方案从水位、水量、工程投资、对周边地区影响、政策处理等方面进行比较,最终提出以建设西溪湿地至钱塘江的地下排水通道、西溪湿地内部调蓄、分区建圩的组合方案为推荐方案。经分析认为,推荐方案可有效减轻杭州市城西地区的洪涝问题。     

短纤维/橡胶发泡复合材料的微观结构及拉伸破坏机理

对锦纶短纤维增强的NR发泡材料的微观结构及拉伸破坏行为进行了研究，并分析了其破坏机理。采用未处理短纤维增强的NR发泡材料中短纤维成为泡孔的成核点，并大部分悬空在泡孔中，拉伸破坏时泡壁与短纤维结合处容易出现应力集中，成为裂纹的起始点，失效时短纤维大部分被抽出；预处理短纤维能与橡胶基体之间产生良好的粘合，从而处于橡胶基体中。其短纤维增强的NR发泡体拉伸产生的裂纹扩展时遇到纤维，纤维能起到承载应力、使应力转向、阻止裂纹扩展的作用，一定程度上改善了复合材料的拉伸强度等物理性。