A polystyrene based visible light responsive polymer bearing donor–acceptor Stenhouse adduct (DASA) pendants is designed and synthesized. Styrene‐vinylbenzyl chloride copolymer (PS‐co‐PCMS) is prepared by free radical polymerization. Then amino‐functionalized PS‐co‐PCMS is obtained by the nucleophilic substitution reaction between the chloromethyl unit and n‐butylamine. Finally, the prepared secondary amines of the polymer are reacted with 5‐(furan‐2‐ylmethylene)‐2,2‐dimethyl‐1,3‐dioxane‐4,6‐dione to fully change them into DASA pendants. The final DASA‐containing polymer shows a tunable photoswitching property upon irradiation with visible light. A photoinduced contact angle change of water on the spin‐coated film of DASA polymer is observed. The DASA polymer film shows excellent photolithographic performance, with well‐defined patterns being efficiently photofabricated using a suitable mask.
Lignin-based azo polymer-bearing
pseudo-stilbene-type azo chromophores
have been synthesized by a post-azo coupling reaction between the
modified alkali lignin and diazonium salts of 4-aminobenzoic acid
in DMF with high yield. The polymer synthesized was characterized
by using spectroscopic methods. Significant dichroism and surface
relief patterns could be photoinscribed on the prepared azo polymer
films by using appropriate laser beams. Self-assembly of the lignin-based
polymer in selective solvents (THF/H2O) can give uniform
colloidal spheres, which can be elongated along the polarization direction
of the irradiation light. This novel synthesized lignin-based azo
polymer could potentially be used for applications such as reversible
optical data storage, photoswitching, sensors, and other photo-driven
devices, which provide a simple strategy for value-added utilization
of lignin biomass resources.
High toughness with self-healing ability has become the ultimate goal in materials research. Herein, thermoplastic polyurethane (TPU) was linked via host-guest (HG) interactions to increase its mechanical properties and self-healing ability. TPU linked via HG interactions was prepared by the step-growth bulk polymerization of hexamethylene diisocyanate (HDI), tetraethylene glycol (TEG), and HG interactions between permethylated amino βCD (PMeAmβCD) and adamantane amine (AdAm). TPU linked with 10 mol% of HG interactions (HG(10)) showed the highest rupture stress and fracture energy (GF) of 11 MPa and 25 MJ·m−3, which are almost 40-fold and 1500-fold, respectively, higher than those of non-functionalized TEG-based TPU (PU). Additionally, damaged HG(10) shows 87% recovery after heated for 7 min at 80 °C, and completely cut HG(10) shows 80% recovery after 60 min of reattachment at same temperature. The HG interactions in TPU are an important factor in stress dispersion, increasing both its mechanical and self-healing properties. The TPU linked via HG interactions has great promise for use in industrial materials in the near future.
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