Sustainable Polymers with High Performance and Infinite Scalability

Our society has been pursuing high-performance biodegradable polymers made from facile methods and readily available monomers. Here, we demonstrate a library of enzyme-degradable polymers with desirable properties from the first reported step polyaddition of diamines, COS, and diacrylates. The polymers contain in-chain ester and thiourethane groups, which can serve as lipase-degradation and hydrogen-bonding physical crosslinking points, respectively, resulting in possible biodegradability as well as upgraded mechanical and thermal properties. Also, the properties of the polymers are scalable due to the versatile method and the wide variety of monomers. We obtain 46 polymers with tunable performance covering high-Tm crystalline plastics, thermoplastic elastomers, and amorphous plastics by regulating polymer structure. Additionally, the polymerization method is highly efficient, atom-economical, quantitatively yield, metal- and even catalyst-free. Overall, the polymers are promising green materials given their degradability, simple and modular synthesis, remarkable and tunable properties, and readily available monomers.

Mussel-inspired Self-assembly into Polymer Coatings of Different Molecular Weight Electrolytes for Enhanced Self-healing and Corrosion Properties

Self-healing coatings offer tremendous application prospects in the field of preventing metal corrosion because of their superior functionality. The coordination of barrier performance and self-healing ability, however, continues to be difficult. Herein, a polymer coating based on polyethyleneimine (PEI) and polyacrylic acid (PAA) with self-repairing and barrier ability was designed. Introducing the catechol group into the anti-corrosion coating increases the adhesion and self-healing efficiency of the coating, providing a guarantee for the long-term stable bonding between the anti-corrosion coating and the metal substrate. Small molecular weight PAA polymers are added to polymer coatings to increase their self-healing capabilities and corrosion resistance. Because layer-by-layer assembly creates reversible hydrogen bonds and electrostatic bonds that help the coating repair itself when it is damaged, and because the traction of small molecular weight polyacrylic acid speeds up this process. When polyacrylic acid (PAA) with a molecular weight of 2000 was present in the coating at a concentration of 1.5 mg/mL, the coating's self-healing capability and corrosion resistance were at their peak. The PEI-C/PAA45W -PAA2000 coating completed the self-healing within 10 min, and the corrosion resistance efficiency (Pe ) was as high as 90.1 %. The polarization resistance (Rp ) was maintained at 7.67×104  Ω cm2 after immersion for more than 240 h. It was better than other samples in this work. The polymer provides a new idea for the prevention of metal corrosion.