Bio-based PA-grafted bamboo charcoal for improving the flame retardancy of PLA/PCL film without damaging mechanical properties and degradability

Despite the fact that researches on polylactic acid (PLA)/polycaprolactone (PCL) composites has been extensively conducted to date, it is still a severe challenge to increase the phase morphological compatibility and combustion performance of PLA/PCL composites while maintaining material degradability. In the study, a degradable PLA/PCL composite film with excellent mechanical properties and flame-retardant ability was developed by the enhancement of biologically modified bamboo charcoal (BC). In the composite film system, bamboo charcoal (BC) was introduced to regulate the microstructure and internal joint mode of PLA/PCL composite film, as well as acting as a flame-retardant modification carrier to give the blend flame retardant properties. The resulting composite film had exceptional mechanical properties, with tensile strength reaching 17.63 MPa and elongation at break reaching 223.33%. Likewise, there was outstanding flame-retardant properties that the LOI value of the film was 30.8%, the HR and PHRR of only 345.00 J/g·K and 231.53 W/g, respectively, which were attributed to the rich N and P of biologically modified BC. This study provides a new strategy for the preparation of degradable and multifunctional PLA/PCL composite membranes.