Near Neutral Waterborne Cationic Polyurethane from CO2-polyol, a Compatible Binder to Aqueous Conducting Polyaniline for Eco-friendly Anti-corrosion Purpose
This work focuses on two points meaningful in green chemistry, one is providing a practical solution for CO2 transformation into CO2 copolymer, the other is disclosing potential application of CO2 copolymer as water dispersible binder to overcome the bottleneck in heavy metal free anti-corrosion coating. For the first concern, CO2-copolymer like CO2-polyol is synthesized from telomerization of CO2 and propylene oxide using zinc-cobalt double metal cyanide complex as catatlyst and sebacic acid as chain transfer agent. In the second issue, as a 30 year topic, conducting polyaniline with unique anti-corrosion behavior is regarded as heavy metal free anti-corrosion material, but the development of waterborne polyaniline anti-corrosion coating has encountered impasse due to lack of compatible binder, therefore a water borne cationic polyurethane dispersion (CPUD) was developed for this purpose, where CO2-polyol was used as soft segment, meanwhile 1,4-butanediol di(3-diethylamino-2-hydroxypropyl alcohol) ether was synthesized as side-chain cationic extender. Unlike earlier acidic water borne dispersion, such water borne CPUD was near neutral, ensuring good compatibility with aqueous conducting polyaniline dispersion, which was expected to create great chance for new generation of sustainable and eco-friendly metal anti-corrosion material, a million ton scale application for CO2 copolymer once settled.
- This article is part of the themed collection: CO2 Utilization