Introduction

Abstract

This special issue brings together a collection of papers that were presented in a symposium on “Fracture and Relaxations in Polymer Solids” at the 2005 American Chemical Society (ACS) Meeting in Washington DC. This special symposium was held in honor of the 60th birthday of Professor Albert Yee, truly one of the pioneers in the field of polymer science responsible for elucidating the chemistry, physics, and mechanics that govern polymer relaxation, fracture, and yield. Understanding and controlling the way that a material mechanically yields or fails is of enormous technical and economic importance. As a result, in the 70's, 80's and early 90's, yield and fracture was one of the “hot” topics in the polymer field. In the past decade or so there has been considerably less research activity in the fracture and yield of polymer-based systems, even though much remains to be learned. Meanwhile, the innovations on the materials development side have not stopped. We are now seeing a host of new and interesting polymeric compounds, composite or multiphase systems, hybrids that blur the lines between ceramic, metals, and polymers, and even an entirely new field of nanoscale materials. In addition to recent materials developments, scientists also have a host of new and improved analytical or characterization tools that can shed deeper insight in the chemistry, physics, and mechanics of yield and fracture. An equally important motivation for this special symposium, besides looking back to honor the work of the pioneers, is to renew research interests on this critical issue. As long as materials are used in real world or engineering applications, their mechanical properties will always be of major importance. This was clear from the strong participation in the special ACS symposium. Over 35 of the leading experts in the field presented both invited and contributed papers on this topic at this special symposium. This special issue contains a small subset of these papers. Christopher L. Soles