Andreozzi, L.; Martinelli, E. An Electron Spin Resonance Study Comparing Nanometer–Nanosecond Dynamics in Diblock Copolymers and Their Poly(methyl Methacrylate) Binary Blends. Polymers2023, 15, 4195.
Andreozzi, L.; Martinelli, E. An Electron Spin Resonance Study Comparing Nanometer–Nanosecond Dynamics in Diblock Copolymers and Their Poly(methyl Methacrylate) Binary Blends. Polymers 2023, 15, 4195.
Andreozzi, L.; Martinelli, E. An Electron Spin Resonance Study Comparing Nanometer–Nanosecond Dynamics in Diblock Copolymers and Their Poly(methyl Methacrylate) Binary Blends. Polymers2023, 15, 4195.
Andreozzi, L.; Martinelli, E. An Electron Spin Resonance Study Comparing Nanometer–Nanosecond Dynamics in Diblock Copolymers and Their Poly(methyl Methacrylate) Binary Blends. Polymers 2023, 15, 4195.
Abstract
Block copolymers are a class of materials particularly interesting for their ability to self-assemble into ordered structures. In this context, the coupling between environment and dynamics is particularly relevant, given that movements at the molecular level influence various properties of macromolecules. Mixing the polymer with a second macromolecule appears to be an easy way to study these relationships. In this work, we studied a system based on two diblock copolymers of methyl methacrylate as first block and 3-methyl-4-[6-(methylacryloyloxy)-hexyloxy]-4’-pentyloxy azobenzene as second block and their blends with PMMA. The relaxational properties of these systems were investigated by electron spin resonance (ESR) spectroscopy sensitive to nanometric length-scales. The results of the study on the blends were related to the dynamic behavior of the copolymer. The study evidenced the presence of fast and slow molecular sites for the molecular reorientation at nanoscale, modulated by the ability of block copolymer to form supramolecular structures. For blends, the heterogeneities at nanoscale are still detected. However it was found that the presence of the PMMA as the major component of the blends modified their dynamic behaviour.
Keywords
electron spin resonance; copolymers; polymer blends; PMMA; photoresponsive polymers; self assembly; nanoscale relaxation; structural relaxation; scaling law
Subject
Chemistry and Materials Science, Polymers and Plastics
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
