Highly flame-retardant bio-based polyurethanes
Reactive flame-retardants (RFR) based on aliphatic and aromatic structured bromine compounds were synthesised and used to prepare bio-based polyurethane using limonene dimercaptan.
The aromatic bromine containing foams (Ar-1 and Ar-2) showed higher close cell content (average 97 and 100%) and compressive strength (230 and 325 kPa) to that of aliphatic bromine containing foams (Ali-1 and Ali-2).
Effective preparation
Similar behaviour was observed for a horizontal burning test where with a low concentration of bromine (5 wt %) in the foams for Ar-1 and Ar-2 displayed a burning time of 12.5 and 11.8 s while, Ali-1 and Ali-2 displayed burning time of 25.7 and 37 s, respectively. Neat foam showed a burning time of 74 s. The percentage weight loss for neat PU foam was 26.5%, while foams containing 5 wt % bromine in Ali-1, Ali-2, Ar-1, and Ar-2 foams displayed weight loss of 11.3, 14, 7.9, and 14%, respectively. The results suggest that flame retardant PU foams could be prepared effectively by using RFR materials.
The study is published in: Applied Polymer Science, Volume 135, Issue 12, March 20, 2018.
