-
解决方案
-
毛细管流变仪应用文章 Polymer Melts under Uniaxial Elongational Flow: Stress-Optical Behavior from Experiments and Nonequilibrium Molecular Dynamics Computer Simulations
发布:北京仪尊时代科技有限公司浏览次数:632ABSTRACT: Tensile stress and birefringence in both real and model amorphous polymer melts have been measured during constant rate uniaxial elongational flow. We focus on investigations where deviations from the linear stress-optical behavior are pronounced. A rate-dependent contribution to the stress which is not directly related to the intramolecular conformations (stress offset) is detected for both types of macromolecular fluids. Independent of the flow history, during relaxation a linear stress-optical behavior is revealed. Nonequilibrium molecular dynamics (NEMD) computer simulations on the multibead anharmonic spring model are shown to provide insight into the molecular mechanisms underlying the viscoelastic behavior: during relaxation the intermolecular interactions become dominant in correlation with linear stress-optical behavior; the stress offset shown to be very similar to the stress arising in the corresponding simple fluid; the total stress can well be approximated by a sum of three parts which are based on single-particle and single-link distribution functions only; the yield point behavior at high elongation rates reflects the transition from affine to nonaffine motion of bonds and is understood without reference to strong inhomogeneities resulting from local plastic strain production[the chemical structure does not influence the qualitative behavior]; distinct microscopic stress contributions under elongation and subsequent relaxation such as inter- and intramolecular, attractive and repulsive, kinetic and potential contributions are resolved.
2004-11-26上一篇:Interpretation of Mechanochemical Properties of the
下一篇:毛细管流变仪配备挤出胀大单元应用文章 An Experimental Investigation of Capillary ExtrudateSwell in Relation to Parison Swell Behavior inBlow Moldin相关仪器 -
免责声明
①本网刊载上述内容,并不代表本网赞同其观点或证实其内容的真实性,不承担此类作品侵权行为的直接责任及连带责任
②若本站内容侵犯到您的合法权益,请及时告诉,我们马上修改或删除。邮箱:hezou_yiqi
-
认证会员 第 9 年
北京仪尊时代科技有限公司
认证:工商信息已核实
- 产品分类
- 品牌分类
-
仪企号
北京仪尊时代科技有限公司
-
友情链接
-
手机版开启全新的世界m.yiqi.com/zt2117/