Characterization of interfaces in Binary and Ternary Polymer Blends by Positron Lifetime Spectroscopy

11th International Workshop on Positron and Positronium Chemistry

物理学;化学

Ranganathaiah, C.^1,2

Govt. Research Centre, Sahyadri College of Engineering and Management, Adyar, Mangalore

575 007, India^1

Department of Studies in Physics, University of Mysore, Manasagangotri, Mysore

570 006, India^2

关键词: Blend components;    Hydrodynamic interaction;    Immiscible blends;    Interface characteristic;    Miscibility of blends;    Positron lifetime spectroscopy;    Single phase system;    Ternary polymer blends;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/618/1/012022/pdf
DOI  :  10.1088/1742-6596/618/1/012022

来源: IOP

【 摘 要 】

A miscible blend is a single-phase system with compact packing of the polymeric chains/segments due configuration/conformational changes upon blending. Differential Scanning Calorimetry (DSC) is the most employed method to ascertain whether the blend is miscible or immiscible. Positron Lifetime Spectroscopy (PLS) has been employed in recent times to study miscibility properties of polymer blends by monitoring the ortho-Positronium annihilation lifetimes as function of composition. However, just free volume monitoring and the DSC methods fail to provide the composition dependent miscibility of blends. To overcome this limitation, an alternative approach based on hydrodynamic interactions has been developed to derive this information using the same o-Ps lifetime measurements. This has led to the development of a new method of measuring composition dependent miscibility level in binary and ternary polymer blends. Further, the new method also provides interface characteristics for immiscible blends. The interactions between the blend components has a direct bearing on the strength of adhesion at the interface and hence the hydrodynamic interaction. Understanding the characteristic of interfaces which decides the miscibility level of the blend and their end applications is made easy by the present method. The efficacy of the present method is demonstrated for few binary and ternary blends.