Improving dispersion of non-halogenated flame retardant systems using Functional Additives

Many scientific studies have proved that halogenated flame retardants (HFR) such as tetrabromobisphenol A (TBBPA) or decabromodiphenyl oxide (DBDPO) are widespread contaminates to the environment.  Some HFRs have already been phased-out of use in Europe, where the EU has changed its environmental regulations for the plastics industry.  In an effort to stay ahead of legislation, several manufacturers of flame retardant plastic products are replacing HFR additives with eco-friendly non-halogenated systems (NHFR).  Matching current performance of HFRs often requires excessive loadings of hydrated fillers such as magnesium hydroxide, or aluminum trihydrate, which compromise the flow and tensile characteristics of plastic materials.  The objective of this study is to improve the filler distribution using dispersion promoting functional additives in hopes of mitigating the deficiencies in performance of NHFR compounds.  Sixty percent by weight NHFR was loaded into an EVA matrix along with low doses of either functionalized polybutadienes, or styrene-co-maleic anhydride additives.  Preliminary results indicated that flow properties are modestly improved, and that tensile strength is increased.  It is believed that reducing the agglomeration of the filler within the EVA matrix provided the changes in mechanical behavior.  Incorporating an elastic polybutadiene at the inorganic/organic boundary can be account for changes in ductility.  Additional studies to confirm these results are ongoing.