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Halogen-Free Flame Retardant Materials


Background: Enzyme-mediated polymerizations as a new biotechnological methodology in the synthesis of new classes of FR materials with environmental compatibility unsurpassed efficiency and economy in synthesis stability and processing. Flame retardant (FR) additives are an important class of materials that have been used extensively to mitigate this serious deficiency of polymers. Halogenated materials account for about 30% (by weight) of all FR produced globally. Though these compounds are inexpensive and very effective in minimizing the rate of flame propagation they are extremely toxic and environmentally persistent having significant long-term impact on the ecosystem. These additives liberate toxic products and generate toxic/corrosive gases during combustion. Halogenated FRs are recognized as a threat to both air and water ecosystems.In view of their high thermal stability and physical properties tremendous incentive exists for their development as non-halogen-containing-flame-retardant materials compared to the traditional preparation of flame-retardent polymeric material containing halogenated or phosphorous compounds a process which generates toxic corrosive or halogenated gases during combustion along with the materials being highly colored. Technology Description: UMass Lowell researchers have used enzyme-mediated polymerizations as a new biotechnological methodology in the synthesis of new classes of FR materials with environmental compatibility unsurpassed efficiency and economy in synthesis stability and processing. Halogen-free FR additives developed at UMass:SIloxane and its derivative-based FR: Polyorganosiloxane-based polymers made using enzymatic synthesis methods. Its derivatives contain mixed organic-inorganic backbones which further enhances thermal stability and heat-releasing capabilities. These polycarbosiloxanes exhibit excellent potential in fire retardant applications such as polymeric coatings blends wire insulation and composites. Polyphenol-based FR: Synthesized using environmentally friendly methods these oligophenolic FRs ultra-fire resistant with very low heat release capacities (< 20 J/gK) and good char formation comparable to or better than most FR polymers. Unlike halogenated FR that are small molecules (monomers) these phenolic FRs are oligomeric materials that will not leach out of the matrix. As an additive these FRs will remain in the host polymer and prevent flame propagation. These FRs can also be synthesized using sustainably sourced raw materials (natural phenols that are waste byproducts of the food processing industry). This would provide a substantial reduction in the final cost of the oligophenol-based FR additive. Applications: 1) Polymeric coatings 2) Building construction 3) Flame retardants used in insulation materials such as cellulose foamed polyurethane and polystyrene as well as PVC and other materials used in flooring panels piping and other construction products 4) Insulated wire and cable (e.g. both in building wiring and connectivity wiring such as fiber optics) 5) Textiles (e.g. protective clothing carpets curtains and rugs 6) Home furnishing (eg. furniture and mattresses) 7) Vehicle parts 8) Increasing use of lighter weight plastic and composite materials that offer improved fuel efficiency and elevated temperatures in under-the-hood applications due to smaller hotter running engines all contribute to increasing motor vehicle flame retardant demand. 9) Aerospace market 10) Efforts by Boeing and Airbus to improve airplane fuel efficiency through the increased use of composites and other plastics along with the industry’s strict flame retardance standards will drive gains in the aerospace market.


1) Enzymatic synthesis 2) Use of “green” chemistry involves no use of harmful solvents 3) Ability to preserve physical properties over a wide range of temperature 4) Low heat release capacity; non-toxic combustion products 5) No Metal Oxides used 6) Metal oxides used as flame retardant additives require heavy loading which alters the properties of the material 7) Halogen-Free materials 8) Meets European standards no toxic fumes released upon burning no leaching of dangerous chemicals into the environment 9) High Flexibility 10) Flexible and easy to process 11) Significant Cost saving 12) Synthesis process requires low quantities of starting materials

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