Fuente: Journal of applied polymer Lugar: RESEARCH ARTICLE Preparation of brushable polyurea coatings with high weather resistance and mechanical properties using CO2-based poly(ethylene carbonate) diol (PECD) as raw materials.

ABSTRACT
Utilizing carbon dioxide as a feedstock for polymer synthesis accords with the global carbon neutrality target and lessens petroleum resource dependence. The synthesis of organic polymers from CO2, especially polycarbonate polyols for high-performance polyurethanes, has garnered extensive industrial and academic attention. Herein, CO2-based poly(ethylene carbonate) diols (PECD) were first used to synthesize manually brushable polyurea (PUU). Results confirm PECD can prepare PUU with excellent mechanical properties and aging resistance. At an isocyanate index (R = 1.2), PECD-PUU showed a tensile strength of 32 ± 2 MPa and an elongation at break of 615% ± 15%. After 168 h of UV aging (280–315 nm), it retained 69% initial transmittance, 52.3% tensile strength and a low yellow index (YI = 20.71%). By contrast, traditional based PUU (PBA-PUU and PPG-PUU) exhibited poor UV resistance: PBA-PUU only retained 6.2% tensile strength after 168 h UV aging, and PPG-PUU degraded completely within 24 h. Endowed with CO2 utilization, excellent performance and brushability, PECD-PUU is a promising green weather-resistant coating for architecture, automobile and aerospace fields.