A close look at polymer degree of crystallinity versus polymer crystalline quality

Abstract

In the broader polymer field, the term ‘crystallinity’ is often used rather loosely. However, increasingly, it becomes critical to clearly distinguish between degree of crystallinity, which provides the fractional amount of crystalline phase in a polymer, and the crystalline quality, which describes the perfection of the crystalline moieties that may form in a polymer. The reason is that these different structural features dictate important properties of plastic materials, including the mechanical properties of commodity polymers and the behavior of macromolecular ferroelectrics; they also determine which photophysical processes occur in semiconducting polymers. Hence, rigor needs to be applied when establishing structure/processing/property interrelations; and it should become a general practice that specific functions are clearly attributed to the degree of crystallinity, the crystalline quality or a combination of the two. In this perspective, in memoriam of Professor Dick Jones, a long‐time member of IUPAC's Polymer Division, we discuss the challenges of identifying—and distinguishing between—these important structural characteristics when using commonly applied measuring techniques and/or theoretical approaches. This task is often elaborate, as small changes in the chemical nature of the polymer and/or processing conditions selected can have drastic effects on both the crystalline quality and the degree of crystallinity, an issue that combined with the general ambiguity of data obtained with methodologies used to characterize polymer structures, theoretically or experimentally based. © 2023 The Authors. Polymer International published by John Wiley & Sons Ltd on behalf of Society of Industrial Chemistry.

Special issue: visionary polymer research for a better world. The professor R.G. ‘Dick’ Jones commemorative issue

“…His personality explains the great breadth and reach of the papers that we have in this series 6–15 . I’d like to mention some of these briefly, as all are excellent and so very well speak for themselves.…”

“…His personality explains the great breadth and reach of the papers that we have in this series. [6][7][8][9][10][11][12][13][14][15] I'd like to mention some of these briefly, as all are excellent and so very well speak for themselves. The paper by Graeme Moad reflects with gentle humour on how he, Dick and Aubrey Jenkins, a prior Chair of SPT, struggled with the development of a clear terminology for specific types of controlled chain polymerizations, and more particularly with the term reversible-deactivation radical polymerization (RDRP).…”

“…6 In two papers right up Dick's street, are Michael Buback and Greg Russell's work which really is a complete and comprehensive review of the characterisation and understanding around chain-termination in radical polymerizations, 7 and Natalie Stingelin and Blair Brettmann's fantastic paper with their colleagues on degrees of polymer crystallinity versus polymer crystalline quality. 8 We also should spend a moment to reflect on Prof. Melissa Chin Han Chan, who so very sadly, and so young, passed away last year. She was a dynamic and inspiring member of SPT and leader of SPEdits sister committee for polymer education.…”

“…The paper by Graeme Moad reflects with gentle humour on how he, Dick and Aubrey Jenkins, a prior Chair of SPT, struggled with the development of a clear terminology for specific types of controlled chain polymerizations, and more particularly with the term reversible‐deactivation radical polymerization (RDRP) 6 . In two papers right up Dick's street, are Michael Buback and Greg Russell's work which really is a complete and comprehensive review of the characterisation and understanding around chain‐termination in radical polymerizations, 7 and Natalie Stingelin and Blair Brettmann's fantastic paper with their colleagues on degrees of polymer crystallinity versus polymer crystalline quality 8 . We also should spend a moment to reflect on Prof. Melissa Chin Han Chan, who so very sadly, and so young, passed away last year.…”

Predicting the Solubility of Gases, Vapors, and Supercritical Fluids in Amorphous Polymers from Electron Density using Convolutional Neural Networks

“…may lead to the formation of ordered mesophases exhibiting large free volume 320 . A more general issue is the ambiguity of the -crystallinity‖ itself; see, for example, a discussion by Venkatram et al 321 In short:…”