Low Poisson’s Ratio Response in Cellulose Foams Prepared by Directional Crystallization and Two-step Crosslinking
발표자
위서은 (중앙대학교)
연구책임자
이종휘 (중앙대학교)
공동저자
위서은 (중앙대학교), 이종휘 (중앙대학교)
초록
내용
Controlling direction-dependent deformation in polymeric foams remains a central challenge in the design of mechanically adaptive porous materials. Here, anisotropic pore structures were formed via directional crystallization of hydroxypropyl cellulose (HPC), a thermoresponsive polymer exhibiting lower critical solution temperature (LCST) behavior that induces re-entrant pore formation. A two-step crosslinking process using butanetetracarboxylic acid (BTCA) enabled controlled shrinkage and structural stabilization, yielding a stretchable composite after silicone rubber infiltration. Shrinkage strain reached 20% along the crystallization (longitudinal) direction and 30% in the transverse direction. Poisson's ratio decreased to 0.02 under optimized first crosslinking conditions, approaching near-zero values when shrinkage was conducted in a polymer aqueous solution. This strategy enables the development of sustainable cellulose composites for flexible material systems.