178. Nanostructures, linear rheological responses, and tunable mechanical properties of microphase-separated cellulose-graft diblock bottlebrush copolymer elastomers
writer：Sun HJ, Wang XH, Chen Q,* Wang ZG*
keywords：彈性體，纖維素，力學性能，流變學
source：期刊
specific source：Biomacromolecules, 2023, 24, 3647-3656
Issue time：2023年
A series of cellulose-graft-diblock bottlebrush copolymer elastomers (cellulose-graft-poly(n-butyl acrylate)-blockpoly(methyl methacrylate) (Cell-g-PBA-b-PMMA)) with short side chains were synthesized via successive atom transfer radical polymerization (ATRP) to study the influence of varying compositions and lengths of the graft diblock side chains on microphase morphologies and properties. The microphaseseparated morphologies from misaligned spheres to cylinders
were observed by atomic force microscopy (AFM) and small-angle X-ray scattering (SAXS) measurements. These bottlebrush copolymer elastomers possessed thermal stability and enhanced mechanical properties because the PMMA outer block could self-assemble into hard microdomains, which served as physical crosslinks. The viscoelastic responses of these bottlebrush copolymers within the linear viscoelastic (LVE) regime were carried out by the
oscillatory shear rheology. The time-temperature superposition (tTs) principle was applied to construct the master curves of the dynamic moduli, and the sequential relaxation of dense bottlebrush copolymers with different PMMA hard outer block lengths was analyzed. The rheological behaviors in this work could be utilized to build up the connection of microstructures and properties for the application of these bottlebrush copolymers as high-performance thermoplastic elastomers.
https://doi.org/10.1021/acs.biomac.3c00386