3 research outputs found
Quantification of nanoparticle release from polymer nanocomposite coatings due to environmental stressing
<p>Certain engineered nanoparticles (ENP) reduce the flammability of components used in soft furnishings (mattresses and upholstered furniture). However, because of the ENP's small size and ability to interact with biological molecules, these fire retardant ENPs may pose a health and environmental risks, if they are released sometime during the life cycle of the soft furnishing. Quantifying the released amount of these ENPs under normal end-use circumstances provides a basis for assessing their potential health and environmental impact. In this article, we report on efforts to identify suitable methodologies for quantifying the release of carbon nanofibers, carbon nanotubes, and sodium montmorillonites from coatings applied to the surfaces of barrier fabric and polyurethane foam. The ENPs released in simulated chewing and mechanical stressing experiments were collected in aqueous solution and quantified using Ultraviolet-Visible and inductively coupled plasma–optical emission spectroscopy. The microstructures of the released ENPs were characterized using scanning electron microscopy. The reported methodology and results provide important milestones to estimate the impact and toxicity of the ENP release during the life cycle of the nanocomposites. To our knowledge, this is the first study of ENP release from the soft furnishing coating, something that can be important application area for fire safety.</p
One-Pot, Bioinspired Coatings To Reduce the Flammability of Flexible Polyurethane Foams
In this manuscript, natural materials
were combined into a single “pot” to produce flexible,
highly fire resistant, and bioinspired coatings on flexible polyurethane
foam (PUF). In one step, PUF was coated with a fire protective layer
constructed of a polysaccharide binder (starch or agar), a boron fire
retardant (boric acid or derivative), and a dirt char former (montmorillonite
clay). Nearly all coatings produced a 63% reduction in a critical
flammability value, the peak heat release rate (PHRR). One formulation
produced a 75% reduction in PHRR. This technology was validated in
full-scale furniture fire tests, where a 75% reduction in PHRR was
measured. At these PHRR values, this technology could reduce the fire
threat of furniture from significant fire damage in and beyond the
room of fire origin to being contained to the burning furniture. This
flammability reduction was caused by three mechanismsî—¸the gas-phase
and condensed-phase processes of the boron fire retardant and the
condensed-phase process of the clay. We describe the one-pot coating
process and the impact of the coating composition on flammability
Rapid Growing Clay Coatings to Reduce the Fire Threat of Furniture
Layer-by-layer (LbL) assembly coatings
reduce the flammability of textiles and polyurethane foam but require
extensive repetitive processing steps to produce the desired coating
thickness and nanoparticle fire retardant content that translates
into a fire retardant coating. Reported here is a new hybrid bi-layer
(BL) approach to fabricate fire retardant coatings on polyurethane
foam. Utilizing hydrogen bonding and electrostatic attraction along
with the pH adjustment, a fast growing coating with significant fire
retardant clay content was achieved. This hybrid BL coating exhibits
significant fire performance improvement in both bench scale and real
scale tests. Cone calorimetry bench scale tests show a 42% and 71%
reduction in peak and average heat release rates, respectively. Real
scale furniture mockups constructed using the hybrid LbL coating reduced
the peak and average heat release rates by 53% and 63%, respectively.
This is the first time that the fire safety in a real scale test has
been reported for any LbL technology. This hybrid LbL coating is the
fastest approach to develop an effective fire retardant coating for
polyurethane foam