Project Details Definition of Terms Pertaining to Polymers in the Solid State: Molecular Arrangement from the Nano- to the Micrometer Scale

Project No.:
Start Date:
01 January 2017
End Date:
Division Name:


To identify and define the terminology required to describe polymer arrangements in the solid state over various length scales for all types of polymers: semicrystalline, liquid-crystalline and amorphous. The key objective is to facilitate exchanges and communication in research, industry and education from different research and technology fields.


The increasing importance of new types of polymers as well as composites and other complex solids in which polymers are used with other materials like inorganics (metals, ionic and covalent solids), low molar mass materials etc., requires to coordinate as much as possible the terminology of traditional fields including polymer crystallography and polymer morphology/microscopy, with that used in other fields of materials science, in the context of what is often called microstructural characterisation. Indeed, the development of novel characterisation methods has led to new insights into the solid state of polymeric species and beyond. Because of this rapid progress, not only researchers, engineers but also students in materials science, chemistry and physics need a ready reference to the exact definitions of terms, compiled in one document, that can be used to describe the solid state of all types of polymers – semicrystalline, liquid-crystalline or amorphous. This need is enhanced by the fact that polymers are entering new application areas (electronics & photonics, health care, etc.) and as a consequence, researchers and students unfamiliar with classical polymer science terminology are required to communicate with each other. All these scientists need a ready reference to the exact definitions of the unfamiliar terms, which they will encounter. For example, for them it is relevant to know what are the right definitions of new characterisation techniques (e.g. soft X-ray methods, energy-filtered transmission electron microscopy and so on) but also what are the correct terms to describe structural features of polymers, neat and in blends, from the molecular to the microscopic level. What is the difference between an eutectic microstructure and that of blends that are fully miscible? These and many other terms are now commonplace but precise, authoritative definitions have never been compiled in one place for the benefit of not only polymer scientists, materials chemists, soft-matter physicists but also device engineers, tissue engineers or biologists.

This project will produce: A paper in Pure Appl. Chem., the electronic version of which will carry hyperlinks. It should be noted that this is a substantial and innovative advance in itself. It will be published as a recommendation. This project will therefore advance the technology using practiced techniques; and it will permit, in a new and efficient manner, real time cross-referencing throughout IUPAC recommendations, and is expected to impact positively to simplify and to unify IUPAC definitions across the divisions involved in this project.

The Interdivisional Sub-committee on Materials Chemistry will be closely involved to ensure that there will be no development of definitions that might conflict with those arising from future activities in its arena.


July 2020 update – A small sub-task group (Veille, Raos, Stingelin) had met in February 2019 in Milano to prepare the “Microstructure’ document for the Paris meeting in July 2019 with input from the rest of the team via email. Focus was on identifying which terms may need inclusion in the document. In Paris, the entire task group met and agreed on a list of terms and how to categorize them in the following categories: i) General Terms in Physical Chemistry Pertinent to Molecular Arrangement in Polymers; ii) Molecular Features and Short-Range Arrangements; iii) Suprastructure and Long-Range Arrangements; and iv) Assembly, Structure Formation and Morphology Development.

The group has now been identifying for which identified and agreed-on terms definitions exist, which definitions need amending, and which terms need to be defined. Virtual sessions took place in July 2020, times zones allowing, to discuss the terms that need amended definitions or entirely new definitions. A draft manuscript is planned to be ready for circulation to SPT in 2021.

page last updated 28 July 2020