Dafeng Zheng, South China University of Technology
Chang Geun Yoo, State University of New York College of Environmen
Polyvinyl alcohol (PVA) is a water-soluble polymer with high chemical stability, easy film formation, strong gas barrier, and high biodegradability. However, PVA-based film has limited applications because of its poor water resistance caused by the hydroxyl groups on PVA. The hydroxyl crosslinking of PVA with lignin improved the thermal stability and water-resistance properties of the composite film. Moreover, the addition of lignin provided the flame retardancy of the PVA/lignin composite film. Up to 50% of lignin was loaded into the composite film.
PPy@PVA/lignin composite film was also produced via in situ polymerization of Py with PVA/lignin film. The resulting PPy@PVA/lignin composite film showed excellent dispersibility of PPy, remarkable conductivity, and temperature-sensitive properties. Although the tensile strength and elongation at the break of the composite films were compromised with the addition of lignin, they still showed comparable mechanical properties. Also, when the PVA/lignin composite film came into contact with the flame, its flame-contact part rapidly transformed into a carbonized polymer and self-extinguished itself within 2 s. The developed composite film showed great potential for high-quality sensing applications.
