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Invention and Commercialization of Environmentally
Smart Thermosetting Binders
Thermosetting binders give shape and strength to nonwoven fibrous materials, including
fiberglass insulation. The most common thermosetting binders are formaldehyde based, but
concern with formaldehyde’s potential as a carcinogen and as an indoor air pollutant has
sparked research for safer alternatives. Manufacturing operations and products that rely on
formaldehyde-based technologies also require expensive emissions abatement equipment,
employee protection measures, special handling, and transport.
In response, Rohm and Haas Company (ROH) has developed and patented Aquaset™
acrylic thermosetting binders, a family of formaldehyde-free, curable, aqueous solutions of
poly(acrylic acid), triethanolamine, and sodium hypophosphite (NaHP). Hypophosphite
catalysis had been used earlier for esterification in permanent press fabric applications; ROH
adapted it to fiberglass insulation to achieve greater network formation and robust physical
properties. ROH enhanced reactivity and cross-linking by using NaHP as both an esterifica
tion catalyst and a chain-transfer agent. Ultimately, they enhanced the mobility of the polyol
within the curing resin, increased the reactivity of primary alcohols such as triethanolamine,
and optimized the cure temperatures.
Combining these steps, ROH created a class of acrylic thermosets that is an ideal green
chemistry alternative to phenol-formaldehyde resins. The byproduct of cure is water; the
technology eliminates formaldehyde wastes, emissions, and exposures. Aquaset™ technolo
gy is nonreactive, nonflammable, recyclable, and benign at ambient conditions to ease
handling, transport, storage, application, and cleanup.
Johns Manville (JM) has been refining the Aquaset™ technology along with ROH. Since
2002, when it began manufacturing formaldehyde-free fiberglass insulation, JM has con
verted all of its building insulation products to the Aquaset™ technology, eliminating the
emission of more than 200,000 pounds of formaldehyde and one million pounds of ammo
nia each year. JM has also eliminated more than 180,000 pounds of phenol and 280,000
pounds of methanol emissions per year. JM is now the only manufacturer exempted from the
U.S. EPA National Emission Standards for Hazardous Air Pollutants (NESHAP) for Wool
Fiberglass Manufacturing.
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