Flame ecologically friendly

GE Advanced Materials was formed by the merger of the Plastics, Silicons and Quartz Divisions. In 2004 the LX2 plant was opened at Cartagena in Spain. Product developments include copolymer Lexan DVD and ecologically friendly compounds for electric and electronic components which are non-brominated and non-chlorinated flame retardant and which are intended to conform to WEEE, RoHS and certain voluntary ECO ecological standards. Other markets served include PCB as well as mobile phones and their associated battery cases. 

Much remains to be solved in complete replacement of ecologically harmful flame retardants. This is a problem for many years. But the final issue is obvious. All efforts should give positive results in the search for new ecologically friendly flame retardants. 

In this connection one can expect in the near future some new steps in this direction. This does not nesesarly mean the total ban of halogenated flame retardants in the next 5-10 years, but it does actually mean a complete reconsideration of the direction of development of polymers flame retardancy, Obviously, the new efforts will be directed towards ecologically friendly flame retardant systems. Chapter 5 is therefore devoted to some new directions in this area. 

The main flame retardant systems for polymers currently in use are based on halogenated, phosphorus, nitrogen, and inorganic compounds Scheme 1, together with some new ecologically friendly flame retardant systems. 

It can be concluded that polyvinyl alcohol incorporated in nylon 6,6 reduces the rate of heat release and increases the char yield. Cone calorimetry data for permanganate-oxidized polyvinyl alcohol indicate an improvement in peak rate of heat release compared with polyvinyl alcohol alone, but the smouldering process is exothermic. Silicon/stannic chloride systems act as ecologically friendly flame retardants for both nylon 6,6 and polypropylene. 

Zaikov, G.E. and Lomakin, S.M. (1997) New aspects of ecologically friendly polymer flame retardant systems. Potym. Plast. Technd. Eng., 36 (4), 647 668. 

The synthesis as well as the recycling and disposal of halogenated compounds such as Polyvinylchloride (PVC), flame retardants (for example Tetrabromobisphenol A), y-Hexachlorocydohexane (y-HCH), Hexachlorobenzene (HCB) leads to the formation of byproducts and residues. Polymers, for example, as well as printed circuit boards or shredder residues include problematic substances which, for ecological reasons, cannot be passed on to the environment but have to be supplied to a specific and proper recycling or disposal process. Prior to this background so called "Supercritical Fluids" are of special interest. Supercritical fluids can be used for the synthesis of polymers in an enviromentally friendly way as well as for recycling and disposal processes. 

In the modern polymer industry, the various existing types of polymer flame retardants based on halogens (Cl, Br), heavy and transition metals (Zn, V, Pb, Sb) or phosphorus-organic compounds reduce the risk from pol3nner combustion and p5n olysis, but may present ecological issues. The overall use of halogenated flame retardants is still showing an upward trend, but the above concerns have started a search for more environmentally friendly polymer additives. As a result it is quite possible that the future available flame retardants will be more limited than in the past. 

---