APS March Meeting 2021
Volume 66, Number 1
Monday–Friday, March 15–19, 2021;
Virtual; Time Zone: Central Daylight Time, USA
Session A01: 101 Years of Polymer Science
8:00 AM–11:00 AM,
Monday, March 15, 2021
Sponsoring
Unit:
DPOLY
Chair: Connie Roth, Emory University
Abstract: A01.00001 : Block Polymers: Extraordinary Consequences of a Few Covalent Bonds*
8:00 AM–8:36 AM
Live
Abstract
Presenter:
Frank Bates
(University of Minnesota)
Author:
Frank Bates
(University of Minnesota)
Block polymers are a ubiquitous form of macromolecules, exploited in myriad areas of fundamental research, and increasingly prevalent in commodity and value added commercial products. These materials are formed by linking together two or more homopolymers with covalent bonds, thus producing hybrid materials embodied with physical properties associated with the individual blocks. This lecture will trace the origins of these fascinating compounds, beginning with the discovery in 1956 by Michael Swarc of “living” anionic polymerization; he immediately recognized the potential to synthesize diblock and multiblock polymers, spawning the development of SIS triblock copolymers, marketed as thermoplastic elastomers in the early 1960’s. By the end of that decade experiments had established the basic molecular weight and composition dependence of nanoscale spherical, cylindrical, and lamellar morphologies in diblock and triblock copolymers. Subsequently, the triply periodic gyroid network phase was added to this list of morphologies. Theory soon followed, catalyzed by the seminal work of Helfand and Leibler, culminating today in the remarkably predictive self-consistent field theory (SCFT). The pace quickened as additional blocks were combined together leading to dozens of documented phases in ABC triblock and higher order multiblocks. And recently, Frank-Kasper and quasicrystalline phases have been discovered in compositionally asymmetric diblock copolymers that form nominally spherical particles. Extraordinary advances in controlled polymerization during the past 3 decades (e.g., RAFT, ATRP, ROMP) has enormously expanded the list of polymers that can be coupled together by individual covalent bonds, offering seemingly unlimited possibilities for creating nanostructured materials of unparalleled sophistication.
*National Science Foundation DMR-1801993