高聚物流变性能预测与研究

根据影响高聚物流变性能的各因素之间的关系,运用Matlab软件建立一个人工神经网络。对5种高聚物材料进行实验;用实验数据对网络进行训练,并对高聚物流变性能进行预测;将预测和实测的结果进行分析对比。结果表明,用人工神经网络的方法预测高聚物的流变性能是可行的,预测精度较高,平均误差小于5%。     

AOT/水层状体系流变性能研究

研究了AOT/水形成的层状体系的流变性能,考察了在不同剪切速率下该体系的黏度、储能模量和耗损模量。实验结果为继续深入研究液晶类表面活性剂聚集体的流变性质提供了基础的实验数据,对该体系在石油开采、药物缓释等方面的应用具有指导意义。     

聚烯烃色母粒流变性能与应用性能研究

采用国产颜料制备色母粒,并测试其分散性能,找到了聚乙烯蜡含量为8%的最优配方,针对该性能优异的色母粒,测试其表观黏度、非牛顿指数等流变参数,并重点讨论了其流变性能.实验结果表明色母粒共混物熔体的表观黏度随剪切速率的增大而降低,非牛顿指数小于1,符合假塑性流体流动规律,色母粒共混物熔体是假塑性流体.这些影响色母粒应用性能的流变数据可为色母粒配方设计和改进提供依据.     

纤维素/NMMO/水溶液流变性能的研究

研究了不同聚合度的纤维素/NMMO/水溶液以及在添加剂NH_4Cl存在下的溶液的流变性能,并将流变性能与纺丝性能进行对照分析,此外,还通过动态流变实验的分析比较了不同纤维素浆粕的相对分子质量及其分布。     

基础理论

<正>TQ 340.120144009纤维悬浮液的结构和流变性能Eberle Aaron P.R.…;Applied Polymer Rheology,2012,p.113(英)综述了纤维悬浮液的流变性能以及流变性能与微观结构之间的联系。文章中收录了目前对长、短纤以及牛顿、非牛顿悬浮介质的理论加工方法。此外,还讨论了流变性能的实验研究,以及流变性能     

炭黑对天然橡胶动态性能的效果和影响

介绍了不同炭黑系列的特性,对不同胶料的基础配方进行了实验,经过了胶料混炼和模压硫化等操作,通过检测和分析讨论胶料的流变性能数据及其它标准物理数据之间的关联,确定了炭黑对胶料的标准物理性能上的影响。     

风电叶片VIMP用环氧树脂体系流变性能研究

对两种风机叶片真空导入模塑(VIMP)工艺用环氧树脂体系的流变性能进行了研究,在黏度实验的基础上,依据双阿累尼乌斯方程建立了与实验数据较为吻合的流变模型.结果表明,两种树脂体系的黏度变化略有差异,在25～ 55℃的范围内,其黏度都低于500 mPa·s,且低黏度保持时间大于30 min,符合风机叶片VIMP工艺对树脂低...     

甲酸盐无固相钻井液高温高压流变性研究

甲酸盐钻井液在国外高温高压井的应用效果表明,其弥补了常规高密度钻井液的缺陷,在高温高压井中具有较好的应用前景。为考察在高温高压条件下甲酸盐钻井液的流变性能,以实验室研制的甲酸盐钻井液为研究对象,用Fann50SL型高温高压流变仪对甲酸盐钻井液的流变性能进行了测定,并利用回归分析的方法对实验数据进行处理。实验结果表明,在高压条件下,甲酸盐钻井液的表观粘度和塑性粘度随温度的升高而降低。回归分析表明在高温高压条件下,甲酸盐钻井液流变模式遵循着赫-巴模式;同时建立了预测井下高温高压条件下甲酸盐钻井液表观粘度的数学模型。实验数据验证表明,利用该数学模型计算出的数值与实测值吻合度较高,这为甲酸盐钻井液的现场应用提供了计算依据。     

NDZ—101钛偶联剂对聚丙烯—碳酸钙体系作用的研究

本实验采用南京大学研制,由南京战斗化工厂生产的NDZ—101单烷氧基钛酸酯偶联剂,对轻质碳酸钙进行活化处理,通过高速搅拌、共混等工序,制成聚丙烯—碳酸钙体系(以下简称PP—CaCO_3体系)。该体系通过压片和注射两种方法制成试样,进行力学性能和流变性能试验。证明该体系的冲击强度、伸长率、硬度、模量、耐热性、尺寸稳定性和流变性能,均得到明显改善,同时达到降低制品成本的目的。本文提供了力学性能和流变性能试验数据,可供参考。     

聚酰胺1010加工流变性能的研究

通过转矩流变和剪切流变实验，讨论了聚酰胺１０１０的加工流变性能，并获得了转矩流变性能参数、不同剪切速率区的非牛顿指数，以及不同剪切速率下的粘流活化能。     

流变模型的参数拟合系统

本文介绍了聚合物熔体流变模型的参数拟合系统的主要功能以及流变数据的数据库内表达方式即数据结构,给出了同一材料不同流变模型下的参数,表明了该系统能较好地完成参数求解的任务,为流变数据的应用提供了方便。     

Melt rheology of polymer blends

The rheological behavior of polymer blends is compared with that reported for emulsions, block polymers and homologous polymer blends. It has been shown that the properties of polymer alloys frequently differ from those of these “model” systems—the principal difference being the lowering of at least one rheological function below the value predicted In the log-additivity rule. Primarily, the most recent (post 1977) results are reviewed. The data obtained by the authors on the flow of poly(ethylene terephthalate)/Polyamide-6,6 are discussed in detail.     

A Note on the prediction of polyethylene melt rheological properties from molecular weight distribution data obtained by gel permeation chromatography

In the present study, a modification of the method previously presented by the authors for predicting rheological properties of linear polyethylene melts from gel permeation chromatography (GPC) data is presented. The modification involves independent values of the zero shear viscosities for melts rather than generating these values internally. The comparison between the experimental zero shear viscosity values and those calculated from GPC data is shown to be very good.     

Über die rheologischen Eigenschaften von lipophilen Grundlagen

Rheological Properties of Lipophilic Bases Investigations on suppository bases showed that pharmaceutical properties of these products are dependent on their rheological properties. The authors assume that rheological properties can serve as criterium for useful properties of lipophilic pharmaceutical bases.     

Determination of rheological parameters from parison extrusion experiments

The parison extrusion and the effects of post-extrusion swelling and sagging in the blow molding process have been studied by several authors and some qualitative relationships with rheological parameters have been attempted. The aim of this work is to show that, under some simplifying assumptions, the relevant rheological parameters—the swelling of the parison and its tensile compliance—can be directly determined from the viscoelastic analysis of the process. The reliability of the model has been tested by experiments carried out by the pinch-off mold technique which provides the parison weight profile as a function of both previous extrusion history and mold closing delay. First of all it has been shown that the proposed model is suitable to represent the data. The swelling behavior shows the expected dependence on time and shear rate and the long-time swelling data compare well with those determined by capillary extrusion experiments. It has also been found that the measured tensile compliance is of the same order of magnitude as that determined by conversion of tensile relaxation experiments; however, in the blow molding experiments the compliance of the parison decreases with increasing extrusion shear rate, i.e., by increasing the induced anisotropy of the polymer. As rheological examples, the performance displayed on both industrial and laboratory machines is discussed for three high density polyethylenes.     

Calendering poly(vinyl chloride): Theory and experiments

An isothermal model for the calendering of power-law fluids which exhibit a slip boundary condition is presented. This model is based on lubrication approximation and Gaskell's theorxy. It Predicts sheet thickness, pressure distribution, velocity profiles, torque and power from rheological data for the melt and machine parameters. The predictions (sheet thickness, pressure distribution and torque) are compared with a set of experimental data for rigid poly(vinyl chloride)(PVC) provided to the authors by Solvay & Cie S.A.     

固体推进剂螺旋压伸挤出过程流变模型建立

在对固体推进剂的螺旋压伸过程进行研究的基础上,探究了一种新型的固体推进剂流变模型的建立方法,即采用最小二乘法拟合基于毛细管流变仪测试所得数据,得到初步固体推进剂流变本构模型,利用Polyflow有限元仿真软件模拟毛细管流变仪测试过程,对流变本构模型参数进行修正,确定最终的推进剂流变本构模型.通过实验数据拟合与有限元模拟...     

塑料材料的流变实验与流变参数拟合

阐述了塑料材料流变参数在注射成型模拟中的重要意义，简要介绍了流变数据的测试方法，采用基因遗传算法实现流变参数的拟合，并通过实例验证了所开发的拟合算法的正确性及流变参数对CAE分析结果的影响。     

应用OriginPro 8.5软件建立流变数据处理系统

介绍了一种应用OriginPro8.5软件建立流变数据处理系统的方法。通过应用OriginPro8.5软件建立相应分析模板,对流变测试得到的温度、剪切速率、剪切应力和剪切粘度等实验数据进行处理,可以方便快捷地得到样品的流变曲线、非牛顿指数以及粘流活化能等分析结果。     

Nonisothermal Crystallization Kinetics of an Ethylene‐Vinyl‐Acetate: I Calorimetry Versus Rheology

The knowledge of the thermo‐mechanical response of polymers during crystallization is of seminal importance for process control and modeling. Among the other subtle findings, the crystallinity‐rheological simplicity, resembling the thermo‐rheological one, was frequently reported, based on the observation that the same amount of crystallinity induces the same rheological hardening to the polymer, regardless the crystallization conditions. The crystallization kinetics, which is a fundamental issue in polymer science, is investigated with differential scanning calorimetry (DSC) measurements. However, the poor agreement of calorimetric data with data coming from rheological investigation remains a debated issue. The crystallization kinetics of a commercial poly‐ethylene‐vinyl‐acetate copolymer (EVA) is here investigated both with DSC and rheological measurements. EVA is a nice model system since its melting point is below 100°C, thus allowing avoiding all the experimental shortcomings related to thermal degradation. We show that DSC and rheological crystallization data satisfactorily agree for the investigated copolymer and thus we conclude that all the discrepancies found in the literature must be principally due to experimental artifacts. Moreover, the observed agreement between DSC and rheological data confirms that the rheological hardening is proportional to the volume of crystallites only and not to the modality in which the crystallization takes place. POLYM. ENG. SCI., 59:2557–2563, 2019. © 2019 Society of Plastics Engineers