Quimica, Chemistry: Flame retardants of last generation. Applicability in polyolefins

Certain European directives and in particular the directive 2002/95/EC on the restriction of use of certain hazardous substances in electrical and electronic equipment, are pushing to be eliminating the use of halogenated ignifugantes in all kinds of materials. Although Decabromo Difenileter is an exception (as the Commission's decision taken on October 15, 2005), the fact is that is spreading gradually ignifugantes the use of halogen-free in other applications.
In this context, substances such as graphite expandable, and various types of nanorefuerzos constitute routes further moves in the field of fireproof plastics.

The nanocomposites differ from traditional composites in the size of reinforcements, at least at one of its dimensions presents lengths in the nano scale, compared to the normal reinforcements micron size. The dispersal of such nanocargas in a plastic matrix, gives the material a substantial improvement in physical properties, thermal and mechanical.

The influence of different nanorefuerzos as nanoarcillas, nanoparticles of silica, carbon nanotubes and nanofiber in the fire behaviour of plastics, is being studied very much in isolation and in combination with other ignifugantes and smoke suppressants.

In this regard, polyolefins are one of the parents surveyed more in the field of nanocomposites, and particularly on improving its reaction to fire.
Traditionally, fireproofing systems more employees in polyolefins differ depending on the application (automotive, electrical-electronic, or construction) but also depending on the type of polymer (polyethylene or polypropylene). In general the most widely used ignifugantes, were based on chlorinated paraffins and metal hydroxides.

On the other hand, nanorefuerzos that the largest number of applications marketing degree and have achieved are the nanoarcillas and nanofiber carbon nanotubes and single or multiple wall. The interest of its implementation in polyolefins, se basa en el que se produce positive effect in reducing time of ignition and the elimination of leakage due to the formation of a layer of charcoal that protects the rest of the material spreading fire.

Within this framework, and within a project funded by the Department of Industry, Commerce and Tourism, Gaiker, has undertaken an effort to develop formulations fireproof polyolefins based nanorefuerzos and other ignifugantes halogen-free. The compounds obtained, have been assessed on its reaction to fire.