Seafood consumption generates large volumes of shell waste, composed of calcium carbonate, mineral oxides and some organic materials. In a new study, ground and washed sea shells were tested as a flame retardant in ABS polymer. 25% loading did not significantly modify ABS mechanical properties and enabled a 40% decrease in peak heat release rate and a nearly 50% increase in time to ignition compared to pure ABS.
The seashells improved fire performance somewhat more than pure calcium carbonate, suggesting a positive impact of the other minerals present, e.g. iron. Previous studies reported that a combination of ground oyster shells and a phosphorus PIN flame retardant (Clariant Exolit AP760) can provide fire performance for polypropylene.
“Highly flame retardant green composites using seashells”, Moustafa, Duquesne, Darwish & Youssef, Plastics Research Online, 31st March 2016
“Clariant’s Exolit® ensures protection for renewable polymers in oyster shell – reinforced polypropylene 20th January 2014 and pinfa Newsletter n°38.