高密度聚乙烯的壁面滑移行为

用双筒毛细管流变仪和旋转流变仪研究了两种牌号的高密度聚乙烯(HDPE)熔体的壁滑行为,考察了发生壁滑的临界剪切应力。通过剪切速率扫描的方法发现两种牌号的HDPE熔体在较高的剪切速率下均发生粘滑转变,在150～230℃温度范围内,HDPE发生粘滑转变的临界剪切应力位于0.20～0.38 MPa范围内,与文献报道值一致;而且发生粘滑转变的临界剪切应力随温度线性增加,这与B rochard和de Gennes提出壁滑的解缠机理一致。用壁滑外推长度表征壁滑程度,发现两种牌号的HDPE熔体的壁滑外推长度均处于0.05～0.09 mm范围内。     

Superior real time method to evaluate photo‐curing resin by means of rigid‐body pendulum rheometer

The objective of this article is to establish a new method in evaluating photo‐polymerization resin reaction behavior, and to use the trends resulting from past evaluation methods and those already known to prove the feasibility of this method. Another objective is to compare the data gathered using the differential photo calorimeter (DPC) method and RPT on different photo‐polymerization resin systems to illustrate that the application of RPT on photo‐polymerization resin studies is more suitable. Experiment results show that the trends through the real time method using oxide series acrylate research through rigid‐body Pendulum Rheometer, the photo‐curing behavior under the various parameters of monomer functionality, and photo‐initiator concentration can all be observed. Comparing the DPC and RPT methods on polyester acrylate series, when the oligomer of tetra‐functional polyester acrylate is added with a different ratio of the monomer of propoxylated neopentyl‐glycol di‐acrylate, DPC evaluation methods show that the differences in observation are minimal. However, when RPT was applied, not only were the differences in reaction speed observed, but also the differences in crosslinking and other data in the hardening process when the balanced time was achieved during the oscillations procedure. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3402–3407, 2006     

HAAKE转矩流变仪驱动单元故障分析

在测绘ＨＡＡＫＥ转矩流变仪驱动电路的基础上，对电路进行深入分析研究，提供了仪器正常工作时则电路参数与波形，分析了常见的故障及原因，提出排除故障的思路及办法。     

Flow visualization and extrudate swell of natural rubber in a capillary rheometer: Effect of die/barrel system

An investigation was carried out to examine the effect of die/barrel system on the flow patterns and extrudate swell of natural rubber in the barrel of a capillary rheometer, using a colored tracer as the visualization technique. The capillary rheometer used in this work had two dies located along the barrel, which is novel in rheometer design. The flow of the rubber in the upper barrel was dependent on the piston/barrel action and changed with piston displacement, whereas the complexity of the flow in the lower barrel was dependent not only on the piston displacement, but also on the geometry of the upper die design. The flow patterns that developed in the whole barrel were independent of the die located at the bottom of the barrel. In addition, the change in extrudate swell was associated with the flow occurring in the barrel, residence time, elastic characteristic, and the temperature rise during the flow. It was concluded that the general style of the flow patterns of natural rubber was greatly dependent on the die geometry that the material had previously moved past. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2525–2533, 2001     

转矩流变仪在测定PVC树脂塑化性能方面的应用

介绍了运用附带数据处理机的流变仪PL2000-6分析通用PVC树脂的流变行为,通过“相关程序”研究了国内外同牌号PVC树脂的熔融曲线,发现国产PVC树脂和进口产品在塑化性能方面存在着一定的差距。     

基于动态剪切流变仪的沥青砂浆力学性能研究

采用动态剪切流变仪对不同老化条件沥青砂浆进行性能测试,分析其路用性能。结果表明：紫外和热氧老化会改善沥青砂浆的高温稳定性,水损害则会弱化沥青砂浆的稳定性;同时,紫外和热氧老化还会在一定程度上对砂浆的低温应力松弛性能造成损害,加快沥青路面的低温开裂,但是水损害却能够提高沥青砂浆的低温应力松弛性能。     

浅谈PVC物料的流变特征

通过分析PVC高聚物的流变性能,讨论了PVC物料在挤出机中和转矩流变仪中的流变特征,阐述了两种流变特征的相互关系及应用。     

转矩流变仪在测定物料加工能耗中的应用

利用转矩流变仪测定物料的加工能耗，从而指导对原料的评价和选择及生产工艺的优化，对合理组织生产，提高产品质量是一重要的辅助手段。     

Crystal morphology of organic pigments and rheology of dispersions in ink and paint media

The purpose of this work is to establish relationships between physico-chemical character of pigments and rheological behaviour of dispersions under steady shear conditions. It has been found that the approximately cube-shaped crystals of CI Pigment Yellow 13-type pigments disperse substantially as individual crystals in (highly viscous) lithographic ink media; strength of structure and plastic viscosity relate simply to number concentration of crystals and area of the pigment/medium interface, respectively. Interpretation of data for dispersions of Red 57.1 pigments in similar media is complicated by persistent face-to-face aggregation of their rectangular plate-shaped crystals. In dispersions of metal-free monoazo pigments (Yellows 1 and 74, Reds 3 and 112) in decorative paint media (relatively low viscosity) strength of structure shows a markedly increased dependence on pigment concentration above a critical concentration. This concentration is different for each pigment and is determined primarily by crystal shape, the less cube-shaped the crystals the lower the critical concentration. Plastic viscosity is dependent upon area of the pigment/medium interface and thickness of adsorbed layer of paint medium.     

PP/蒙脱土纳米复合材料的制备及剪切粘度

应用双螺杆挤出机熔融插层制备出PP／蒙脱土纳米复合材料，X射线衍射表明，PP高分子链已插层进入有机蒙脱土片层之间。应用两种不同缝隙厚度的窄缝流变仪对PP及PP／蒙脱土纳米复合材料的剪切粘度及影响因素进行了研究。结果表明，PP／蒙脱土纳米复合材料为剪切变稀性流体。在190℃和210℃温度下，PP／蒙脱土纳米复合材料呈现类固体的非牛顿流体行为，剪切粘度随着剪切速率的升高逐渐降低。在230℃和剪切速率小于80s^-1的情况下，PP／蒙脱土纳米复合材料呈现类牛顿性流体行为。温度较高时,蒙脱土的含量对复合材料的剪切粘度的影响较为明显。