Fire-retardant plastics
Plastics are everywhere, from fabrics to furniture. One of the major concerns of plastic use is the ease with which they burn, and the related dangers. In recent years Brominated Flame Retardants (BFRs) have been used as the major chemical flame retardant. They are applied to prevent electronics, clothes and furniture from taking fire. However, some brominated flame-retardants are considered persistent organic pollutants known to bioaccumulate with questionable environmental consequences. Alternative fire retardants are being considered in the manufacture of nanocomposite plastics. Nanocomposites are materials that combine one or more separate components in order to obtain the best properties of each component (composite). Thereby, the nanomaterials have structured components with at least one dimension less than 100 nm. In nanocomposite, nanoparticles (clay, metal, carbon nanotubes) act as fillers in a matrix, usually polymer matrix. The fire retardant properties of these filler have been investigated. Specifically, concepts to achieve nanodispersion of polypropylene (PP) and polyamide (PA6) nanocomposite systems were developed. Using raw bentonite as the filler in PA6, it was demonstrated that the flammability of the composite was reduced by over 50 % compared to the original PA6 material. As far as flammability ratings are concerned, the composite reaches a VO 94 UL (Underwriters Laboratories) classification. For the PP, clay modified by organic groups was employed as filler. However, this did not lead to improved flame retardation. The combined use of nano and micro fillers did however increase the mechanical and fire retarding performance of the composite. This development is a major contribution to the search for plastics which are fire retarding, without any potential environmental hazards. Areas of application are wide ranged similarly to the use of plastics.
