Carbon Dioxide-Based Polyols as Sustainable Feedstock of Thermoplastic Polyurethane for Corrosion-Resistant Metal Coating

Abundant, inexpensive, renewable, and nontoxic carbon dioxide (CO2) has become an attractive feedstock for chemical and polymer syntheses. The use of CO2 as a sustainable precursor for polyurethane has become prominent in polymer industry. In this study, polyols produced from CO2 were successfully incorporated into thermoplastic polyurethanes (TPUs). The thermal, mechanical, shape memory, and anticorrosion properties of the TPUs were investigated. TPUs with CO2-based polyols appeared as hard plastics with relatively high Tg and tension set values. The rigid carbonate units of the CO2-based polyols reduced the softness of the polyol chains. The CO2-based polyols also afforded TPU with excellent shape memory characteristics, exhibiting shape fixity and shape recovery values of almost 100%. Interestingly, the incorporation of CO2-based polyols into TPUs improved the anticorrosion characteristics, regardless of the corrosive media. The improved anticorrosion characteristics stemmed from the robust, hydrophobic, and blocking properties of the carbonate units. This allows the TPU to be used in hard coatings for high-performance applications. CO2-based polyols are promising alternatives to conventional petroleum-based polyols and can be used for the fixation of waste CO2 and decreasing the carbon footprint of chemical processes.