Rapid, solvent-free synthesis of poly(1,4-butadiene) in ambient conditions is demonstrated by frontal ring-opening metathesis polymerization (FROMP) of 1,5-cyclooctadiene (COD). Furthermore, cross-linked copolymers with a wide range of tunable properties are readily prepared by FROMP of mixtures of COD and dicyclopentadiene (DCPD). Specifically, glass transition temperature and tensile modulus are varied from −90 to 114 °C and 3.1 MPa to 1.9 GPa, respectively, by controlling the comonomer ratio. Copolymers with subambient glass transition temperature exhibit robust elastomeric behavior, with the ability to repeatedly recover from large elastic deformations. As a demonstration of the capability of this manufacturing strategy, gradient materials are fabricated in less than a minute with spatially controlled properties for multistage shape memory actuation. This simple yet powerful manufacturing strategy enables rapid synthesis of copolymers ranging from elastomers to thermosets with precise control over thermomechanical properties.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: This research was supported by the AFOSR Center for Excellence in Self-Healing, Regeneration and Structural Remodeling Award #FA9550-16-1-0017 (L.M.D) and by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering Award #DEFG02-07ER46471 (Q.W.). L.M.D. thanks the National Science Foundation for a Graduate Research Fellowship.
O.A. thanks King Abdullah University for Science and Technology (KAUST) and the Saudi Cultural Mission for sponsorship. The authors thank Bhaskar Soman for assistance with X-ray scattering.