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Computer Simulation of Structure Prediction for Polymer Blend and Alloy

聚合物共混物和合金结构预测的计算机模拟

基本信息

批准号：
07651111
负责人：
KAJIWARA Toshihisa
金额：
$ 1.02万
依托单位：
Kyushu Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

项目摘要

We considered based upon the previous research survey including our study that the dynamics simulation is effective for the prediction of structure development of fiber-filled and particle-filled polymer composite materials, polymer blends and polymer alloys and we can systematically deal with these predictions as a simulation technique.First we developed the prediction technique of three-dimensional behavior of fibers in a composite material by means of the dynamic particle simulation. We predicted the orientation, deformation and break of a single fiber in simple shear and elongation flow fields and the obtained results were found to be physically reasonable and be in agreement with some experimental results. Also we extended this technique to fiber-concentrated material by adding the fiber-fiber interaction. This simulation technique can be simplified and become easier for the distribution prediction of polymer blend because that only the particle trace is performed. It can be appli … More ed to the prediction of particle dispersion in particle-filled materials by adding the cohesive power, and to structure prediction in polymer alloys if we can make the successful model for the break up of liquid drop.Next we developed the prediction technique of polymer configuration using the spring-bead model by means of the molecular dynamics simulation and discussed the equivalence of the molecular model to the actual polymer. The simulation results varying the numbers of segments and chains showed that this model can represent the relaxation behavior of real polymer chain. However this model cannot appropriately represent the excluded volume effect when existence of several scores of monomers are assumed in a segment. The new model have to be discussed as several hundreds of monomers in a segment are required in order that the results by molecular dynamics are related to the continuum physical properties. We proposed the new model, "tube model", which can successfully show the extended volume effective and still have the merit of the spring-bead model.Last we developed the calculation method of optimized determination of material constants from experimental data of rheological properties for several constitutive equations and discussed the applicability of material models. It was found that several models can predict the material behavior in shear and elongation fields for weak-entangled polymer systems but multi values of non linear material constants in each relaxation mode and large number of relaxation modes were required for complicated systems. Less

基于以往的研究，包括我们的研究，我们认为动力学模拟对于预测纤维填充和颗粒填充的聚合物复合材料、聚合物共混物和聚合物合金的结构发展是有效的，我们可以作为一种模拟技术系统地处理这些预测。首先，采用动态粒子模拟的方法，建立了复合材料中纤维三维行为的预测技术。本文对单根纤维在简单剪切和延伸流场中的取向、变形和断裂进行了预测，所得结果在物理上是合理的，并与一些实验结果相吻合。我们还通过添加纤维-纤维相互作用将该技术扩展到纤维浓缩材料中。这种模拟技术由于只进行了粒子轨迹的计算，简化了聚合物共混物的分布预测。若能成功建立液滴破碎模型，则可进一步应用于颗粒填充材料中颗粒分散的预测，以及聚合物合金中的结构预测。在此基础上，通过分子动力学模拟，建立了基于弹簧珠模型的聚合物构型预测技术，并讨论了分子模型与实际聚合物的等价性。不同链段数和链段数的仿真结果表明，该模型能较好地反映真实聚合物链的弛豫行为。然而，该模型不能很好地反映在假设一个段中存在几十个单体时的排除体积效应。为了使分子动力学的结果与连续体的物理性质相联系，在一个区段中需要数百个单体，因此必须对新模型进行讨论。我们提出了一种新的模型——“管模型”，它既能很好地显示扩展体积的有效性，又具有弹簧模型的优点。最后提出了几种本构方程流变特性实验数据优化确定材料常数的计算方法，并讨论了材料模型的适用性。研究发现，对于弱纠缠聚合物体系，几种模型可以预测材料在剪切场和延伸场的行为，但每种弛豫模式下的非线性材料常数都需要多个值，而对于复杂的体系，则需要大量的弛豫模式。少