Purpose & Overview
Polymer blending and alloying is one of the most active areas of polymer materials development because it offers the opportunity to create highly profitable, specialty materials designed to meet specific customer needs at minimum product and development cost. Because of this high level of activity, the art of blending and alloying is rapidly becoming a science.

Who should attend?
This course is designed to introduce the new worker in the field to the evolving scientific principles, while giving the experienced worker an overview of the field outside their specialization. It is especially designed to present the material in a simple, clear manner, emphasizing the concepts rather than the mathematics, so that many people outside R&D such as those engaged in manufacturing, business development and marketing can come away with a practical understanding of this science and technology as it applies to their materials and products.

About the Instructor: Donald E. Witenhafer
Donald Witenhafer has over twenty-five years experience in industrial, polymer R&D and is currently working as a consultant on polymer technology and project management in Columbus, Ohio. He has a Ph.D. degree in Polymer Science from Case Western Reserve University and over 25 patents and publications.

Seminar Content
Introduction and Basic Principles • Role of crystallization • Glass transition in polymers • Miscible and immiscible blends • Typical blend morphology • Mechanism of impact modification • Compatibilization
Thermodynamics and Phase Equilibria • Introduction to free energy of mixing • Why entropy effects are small in polymers • Chemistry factors controlling miscibility • Blending principles and adhesion between polymers • Phase diagrams: lower critical solution temperature, upper critical solution temperature, generalized phase diagrams • Flory-Huggins equation • Copolymers and Blending • Copolymer representations - temperature composition plots, miscibility maps
Compounding and Processing Blends • Miscible blends • Immiscible blends • Principles of dispersive mixing
Polyphenylene Ether-Polystyrene Blends as an Example of Commercially Miscible Blends
Commercial Thermoplastics Elastomers • Based on crystallization crosslinking • Based on phase separation crosslinking • Based on ionic crosslinking • Based on dynamic vulcanization
Experimental Methods to Determine Miscibility • Glass Transition Methods - differential scanning calorimetry, dynamic mechanical methods, dielectric relaxation, thermo-optical • Scattering Methods - electron microscopy, optical microscopy, light scattering, x-ray scattering, neutron scattering • Physical Property Methods - density, tensile strength, impact strength, other • Problems Associated With Each Method
Polycarbonate-Polyester Alloys as Examples of Commercially Significant Immiscible Blends
Use of Solubility Parameters to Predict Miscibility • Principles of concept and calculations • Use for PVC blends • Use for other polar polymers