Kathrin Lehmann, Evonik, presented the company’s range of different organo-modified siloxanes, which act to improve the mechanical properties of polymers containing flame retardants. These can have different branching structure or chemical groups, enabling anchoring in and compatibility with specific polymers.
Examples presented showed how a 1 or 2% loading, either added into the polymer-FR compound, or used as surface coating of the FR before compounding, can significantly improve properties such as appearance, melt-flow, fire performance, mechanical strength, or prevention of die-drool, in polymers including polyamines, polyolefins, polypropylene, EVA/PE. Examples included mineral, phosphorus and nitrogen flame retardants: Evonik is not working with halogenated FRs because of product sustainability objectives.