Journal of Polymer Science Part A: Polymer Chemistry

Azobenzene-containing polymers offer a tremendous advantage and opportunity over other stimuli-responsive materials to interface with biology. Azobenzene's fast, reversible, and innocuous cis-trans geometrical isomerization when irradiated with light can be leveraged into dramatic intra-molecular and inter-molecular changes when intelligently designed in polymeric materials. From photo-reversible micelles and peptides, to controlled drug release and sensing, the versatility of azobenzene makes it a favored photo-switch to be found in many emerging applications.

The reversible complexation reaction of ferrocene and β-cyclodextrin has been applied for preparation of electrically-driven self-healing polymers. Addition of 20 wt % of this agent to a commercial product of car painting successfully brings the self-healing property to the coating product.

In this work, a new paradigm to functionalize poly(ɛ-caprolactone) using α,ω-epoxy esters is demonstrated. The model α,ω-epoxy ester—ethyl 2-methyl-4-pentenoate oxide (EMPO) was synthesized via epoxidation and its incorporation into the PCL backbone via ring-opening copolymerization was investigated. Statistical, random copolymers of CL and EMPO were obtained and copolymerization parameters were determined to be 1.31 and 0.01, for ɛ-caprolactone and EMPO, respectively.

Superparamagnetic and thermoresponsive hybrid nanoparticles composed of poly[di(ethylene glycol) ethyl ether acrylate-co-(oligoethylene glycol) methyl ether acrylate] shell and magnetic Fe₃O₄ core were synthesized via surface-mediated RAFT polymerization. The hybrid nanoparticles exhibited excellent magnetic susceptibility (M_s ≅ 55.1–19.4 emu/g) and showed a temperature-responsive behavior as the temperature changed between 25 and 40 ^°C.

Novel skipped-π polymers comprising π-components connected with 2-substituted trimethylene tethering units that exist as stair-like stacking substructures were synthesized and found to exhibit bathochromically shifted, broadened UV absorption with a unique lower-energy absorption band and largely red-shifted fluorescent emission owing to the extended π-conjugation resulting from through-space π–π interactions in the ground and excited states.