New oligomeric PEI-based flame retardant for PLA

Abstract In this study, a new oligomeric DOPO-containing compound with flame retardant properties was obtained based on polyethyleneimine (PEI). The oligomer was synthesized using the following components: polyethyleneimine, benzaldehyde, and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide. The PEI-based flame retardant in an amount of 8% by weight was incorporated into the polymer matrix of a biodegradable polymer—polylactic acid. The resulting polymer material was tested using a method analogous to the UL 94 test, which revealed a significant reduction in the burning rate of the samples in the solid phase due to charring. The modified samples exhibited a significant reduction in the horizontal burning rate.