Responsive lignin for shape memory applications

POLYMER

卷:160

Article

Nguyen, Ngoc A.^1,2  Meek, Kelly M.^1,2  Bowland, Christopher C.^1,2  Naskar, Amit K.^1,2 

[1] Oak Ridge Natl Lab, Mat Sci & Technol Div, Carbon & Composites Grp, Oak Ridge, TN 37831 USA

[2] Oak Ridge Natl Lab, Chem Sci Div, Oak Ridge, TN 37831 USA

关键词: Thermo-responsive lignin;    Shape memory polymer;    Elastomer;    Shear-induced crosslinking;    Thermal activation;   

DOI  :  10.1016/j.polymer.2018.11.055

来源: Elsevier

【 摘 要 】

We analyze thermally unstable lignin linkages that generate reactive sites and promote crosslinking reactions during thermal annealing at 180 degrees C. This results in significantly enhanced glass transition temperature (T-g ). We use these characteristics of lignin to enhance interfacial reactivity of a lignin-based multiphase polymer synthesized by a dynamic shear process. An approximately 18 degrees C increase in T-g and more than 230% increase in storage modulus (E') are achieved by thermally annealing the 50 wt% hardwood lignin-nitrile rubber composite for 5 h at 180 degrees C. Tunable chemical and physical crosslinks within lignin and rubber resulted in shape programmability demonstrating excellent strain recovery of the synthesized renewable materials. The substantial improvement of the elastic work density of the lignin-based elastomers allows a broader applicable stress window for stress/strain sensing. The renewable materials also exhibit a better strain recovery after thermal annealing.

【 授权许可】

Free