Functional copolymers – Synthesis and applications

Researchers: Michael Luksin, Petra Frank (in collaboration with working group Prof. Dr. U. Jonas, University of Siegen, Germany)

We are currently working in the design, synthesis and potential applications of a series of novel styrenic copolymers. Specifically, some of the synthesized copolymers exhibit flame retardant properties which render them suitable for e. g. applications in E&E, building & construction, transportation, and others.



A novel set of intrinsically flame retardant styrenic copolymers



Polystyrene and styrene copolymers are widely used polymers in building and construction, E&E, transportation, and other applications. They possess multiple favourable properties, but exhibit at the same time very low resistance to fire and flames.[1] Therefore, the generation of a sufficient flame-retardant effect in styrenic polymersremains a challenging field of current applied research.

State of the art flame-retarded styrenic polymer foams use halogenated flame retardants like hexabromocyclododecane (HBCD) or polybrominated styrene-butadiene-copolymers to achieve sufficient fire retardancy.[2] Halogen-free flame retardant systems for polystyrene foams have also been described in recent patents.[3]

In a previous publication it could be shown that, in using a phosphorus-sulfur flame retardant system in polystyrene foams, the chemical environment of the phosphorus atoms in the different flame retardants used did, surprisingly, not influence the flame retardant efficiency in a B2 and an LOI setup.[4] The used flame retardants in this study were of low molecular weight and therefore possess the tendency to migrate out of the polymer.[5] This migration behavior can reduce the long-term flame resistant properties of those polystyrene foams.

It is therefore the target of the current study to overcome the above-mentioned drawbacks of the tested state-of-the-art halogen-free flame-retardants for polystyrene foams. A set of novel, tailor-made halogen-free styrene copolymers with flame retardant properties for building and construction applications was developed by a versatile synthetic building-block-approach in a one-pot, atom-efficient and solvent-free synthesis. in which the route is based on cost-efficient and readily available educts. This challenging novel and environmental-friendly pathway possesses a large potential to provide environmentally friendly and cost-efficient novel styrene copolymers with intrinsic resistance to flames for  a variety of different applications.

[1] Ballast. D.E. et al., Method of foaming a thermoplastic organic polymer containing a nucleating agent and an organic bromide, US3188295 (A) 08.06.1965. [2] Hahn, K. et al., Flame-protected Polymer Foams, WO2011/073141 A1, 13.12.2010. [3] Bellin, I. et al., Flame-retardant System. WO2012/089667 A1, 05.07.2012. [4] Luksin, M. et al., FRPM2019 Proceedings, 26.-28.06.2019, P50. [5] Martinez-Lopez et al., Food Additives & Contaminants: Part A,