Cross-Linking Agents for Enhanced Performance of Thermosets Prepared via Frontal Ring-Opening Metathesis Polymerization

• Published in: Macromolecules 2020-10, Vol.53 (19), p.8360-8366
• Main Authors: Ivanoff, Douglas G, Sung, Jaeuk, Butikofer, Sydney M, Moore, Jeffrey S, Sottos, Nancy R
• Format: Article
• Language: English
• ISSN: 0024-9297; 1520-5835
• DOI: 10.1021/acs.macromol.0c01530

Frontal polymerization (FP) is a self-propagating reaction in which the reactive zone propagates through a monomer solution at a steady velocity. Using FP, polymeric materials are cured rapidly with minimal energy input. Here, we produce high-glass-transition-temperature thermosets via frontal ring-opening metathesis polymerization (FROMP) of dicyclopentadiene (DCPD) with norbornene-based cross-linkable co-monomers that enable tuning of the cross-link density. The glass-transition temperatures of poly­(DCPD) systems are systematically varied from 138 to 219 °C by altering the amount of cross-linking co-monomers in the resin. Front velocities exceeding 5 cm·min–1 enable rapid, solvent-free production of thermoset materials with a 99% degree of cure and yield strength of 57 MPa. The DCPD-norbornene co-monomer resins are cured with 6 orders of magnitude less energy than a traditional oven cure and have a T g nearly 90 °C higher than reported thermosets of DCPD prepared via FROMP.