Novel ‘Greener’ Routes to Halogen-free Flame Retardant MaterialsEPA Grant Number: SU834738
Title: Novel ‘Greener’ Routes to Halogen-free Flame Retardant Materials
Investigators: Nagarajan, Ramaswamy , Bouldin, Ryan , Kumar, Jayant , Ravichandran, Sethumadhavan
Institution: University of Massachusetts - Lowell
EPA Project Officer: Nolt-Helms, Cynthia
Project Period: August 15, 2010 through August 14, 2011
Project Amount: $9,999
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet (2010) RFA Text | Recipients Lists
Research Category: Pollution Prevention/Sustainable Development , P3 Challenge Area - Materials & Chemicals , P3 Awards , Sustainability
Flame retardant (FR) additives, more specifically halogenated compounds are added to polymers to reduce/eliminate the risk of fire. Halogenated FRs release toxic gases on combustion and are extremely persistent in the atmosphere, threatening both air and water ecosystems. Although effective in imparting flame retardancy, halogenated FRs leach out from polymers and cause a variety of health disorders, including cancer. Hence there is an urgent need for the design of new non-toxic FR materials (preferably obtained from renewable resources) to substitute/eliminate the use of halogenated FRs. Our main objective is to develop a new class of non-halogenated flame retardant materials based on phenol and substituted phenols through benign bio-catalytic methods. We will also investigate the possibility of using bio-degradable starting materials for the synthesis of less-toxic FR materials. In addition to the enzymatic approach, a biomimetic approach using hematin as a catalyst will be developed for the synthesis of the FR materials.
Radical scavenging and char forming capabilities are two important requirements for a FR. Phenolics are excellent radical scavengers and can be used as starting materials for the synthesis of FRs. We propose the polymerization of substituted phenols (including non-toxic, renewable monomers - cardanol) using ‘green’ enzymatic (plant peroxidases as catalysts) and biomimetic methods to create a new class of non-halogenated polymeric FRs. This facile one-pot, environmentally benign oxidative polymerization reaction is carried out in ambient conditions yielding polymeric FRs. Due to high char forming capability of polyphenols in the condensed phase, it is well positioned as a less-toxic alternative with comparable flame retardancy. The use of a polymeric FR would also eliminate leaching problems associated with small molecule FRs.
Monomers from industrial wastes/renewable resources will be evaluated as benign starting materials. Biocatalytic routes (enzymatic and biomimetic) will be utilized for the synthesis of substituted polyphenolic FRs. The polymeric phenols will be structurally characterized and their FR properties evaluated using well-established methods like Pyrolysis Combustion Flow Calorimetry, Limiting Oxygen Index, etc. This research effort will result in the development of a novel class of non-toxic polymeric phenols with superior FR properties.