Abstract
The effects of nanometer-sized Mg (OH) 2 were studied on the flame retardancy of Mg (OH) 2 /epoxy polymer composites. The composites were prepared by synthesizing nanometer-sized Mg (OH) 2 and dispersing it into an epoxy resin. The results of a combustion test using nanometer-sized Mg (OH) 2 about 10nm particle diameter, which was produced by wet bead milling process with surface treatment, were as follows : the lower quantitative limit in mixing Mg (OH) 2 as a filler for composing flame-retardant composites was about 40wt% with 10nm size particles, while the limit was about 70wt% with 600nm ones. By the SEM observation after combustion test of the nanometer-sized Mg (OH) 2 /epoxy polymer composites, it was proved that a generated dense charred layer covered all surfaces of the composites.
Nanometer-sized magnesium hydroxide particles contributed in the formation of a dense char surface layer on the sample during the combustion process. This dense char layer blocks off the diffusion of combustible gases generated from polymeric decomposition. This suggests the cause of the remarkable flame retardancy for nanometer-sized Mg (OH) 2 /epoxy polymer composites.
