Work

“Grafting‐to” Polymers of Xylan‐g‐allyl Glycidyl Ether Toughen PEG Hydrogel via Microphase Separation: Thermoresponsive and Photoreactive Molecular Assembly in DLP 3D Printing

Year: 2025

Type: article

Abstract: Utilizing naturally derived biopolymers in the macromolecular design of thermoresponsive polymers offers sustainable and biodegradable smart building blocks to functional materials. Here, a novel graft polymer of xylan-g-allyl glycidyl ether (xylan-g-AGE) that is thermoresponsive to self-assemble and photoreactive in photopolymerization is reported. This research highlights an innovative use of the debranched wood xylan, a chemically engineered linear polysaccharide of β-1,4-linked xylose, as the backbone in grafting polymer, which allows a greater degree of spatial coordination for sidechains than the analogous cellulose. Induced by the reformation of H-bonds and hydrophobic effect, xylan-g-AGE transits from solvated coil chain to self-assembled mesoglobules upon the temperature change above its lower critical solution temperature (LCST). When xylan-g-AGE is used in photoresins to fabricate hydrogels with good geometric fidelity via DLP 3D printing, solvated xylan-g-AGE stiffens the polyethylene glycol (PEG) hydrogel strongly, due to higher crosslink density of available AGE moiety and faster crosslinking rate, while self-assembled xylan-g-AGE toughens the PEG hydrogel better, attributed to the strategy of "dual chemically independent domains" that smartly combines tough domain of PEG and soft domain of self-assembled xylan-g-AGE. Conductive hydrogel is fabricated by incorporating 2D MXene sheets into this hydrogel matrix in DLP printing, which demonstrates superior performance as wearable strain sensors.

Source: Small

DOI: 10.1002/smll.202502129