N. Shukla
Fraunhofer CSE,
United States
Keywords: Phenolic Foam, Thermal Insulation
Summary:
Among the conventional plastic foam insulations used in the U.S. building sector, phenolic foam is the only one that can obtain or exceed thermal resistivity of 8.0 hr·ft2·°F/Btu·in (R-8 per inch). Phenolic foam also inherently satisfies the fire safety codes without the need for costly fire retardants. Despite these benefits, phenolic foam is rarely used in the U.S. buildings due to its corrosion potential and poor mechanical characteristics which led to nation-wide failures of metal roof decks during 1980-90s. In this work, we developed a novel bio-based, less acidic and mechanically stronger phenolic foam insulation derived from low-cost components, including biomass lignocelluloses. Lignin, a rich source of phenol, was used to synthesize phenolic resin, while light-weight nanocellulose fibers were added to mechanically reinforce the foam matrix. Phenolic foam corrosivity is caused due to the use of highly acidic sulphonic acid in its chemistry. Mitigation of the corrosion potential of the phenolic foam was achieved by using less acidic, biobased and inexpensive catalysts.