Scientists demonstrate a new eco-friendly coating that could make polyurethane foam and more flame-retardant

Now, scientists have demonstrated a new coating designed to limit the flammability of wood used in construction, giving people more time to escape a fire and also hindering its spread
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This environmentally friendly flame retardant can also be applied to other flammable materials such as polyurethane foam, textiles and three-dimensional (3D) printed parts
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Home fires account for the majority of fire deaths and cause billions of dollars in property damage each year, according to the National Fire Protection Association
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Installing smoke detectors and fire sprinklers can help, but another approach is to make building materials less flammable
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That's the goal of Dr.
Thomas Kolibaba, who is creating a new coating for these materials
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This treatment, which can be deposited by dipping, spraying or pressure treatment, can make the home safer
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This coating reduces the spread of flames and the generation of smoke, which can limit damage and give people more time to evacuate
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Dr.
Thomas Kolibaba is a graduate student and postdoctoral researcher in Grunlan's lab at Texas A&M University
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The project's lead researcher, Dr.
Jaime Grunlan, observed that the composition of the new coating is environmentally friendly and potentially less expensive than most existing flame retardant treatments
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Kolibaba conducted the research as a graduate student and postdoctoral researcher in Grunlan's lab, building on a polyelectrolyte coating technology envisioned by the team in 2009 and later refined by other scientists
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Many of these coatings are made by soaking a material or something in a solution consisting of one polymer with a large amount of positive charge, and then in another solution consisting of a polymer with a large amount of negative charge , then repeat these steps to achieve the preferred thickness
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The opposing charges attract the polyelectrolyte molecules in the alternating layers to form complexes on the surface of the article, creating a coating that can extinguish flames
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Thomas Kolibaba would love to extend this treatment to wood, but a multi-step approach is out of the question for producers because wood takes a long time to absorb the chemicals
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Through additional research, he adapted Grunlan's other method and was able to reduce the steps to two: one soak to coat the wood, and a second soak in a different solution to treat the paint by switching the pH.
layer
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However, the second solution always became viscous, so the reconstituted process was still not suitable for consumer or industrial applications
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In the latest change, Thomas Kolibaba has overcome this problem, saying the process will be easily adopted by consumers or industry
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He soaked plywood in an aqueous solution consisting of the monomer hydroxyethyl methacrylate phosphate (HMP), the positively charged polymer polyethylene (PEI), and a photoinitiator called TPO
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Instead of dipping the wood into the solution a second time to cure it, he exposed it to ultraviolet (UV) light for a few minutes
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This allows TPO to turn HMP into a negatively charged polymer, which then forms a polyelectrolyte complex with PEI
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The resulting coating was clear and only a few microns thick, so it didn't change the look of the wood, just added weight to it slightly
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In laboratory flame tests, the treated wood reduces the amount of heat it emits when burning and rapidly develops a superficial charcoal layer that protects the underlying wood -- properties that can curb the spread and destruction of fires
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It also reduced smoke production by 56%, a very significant improvement
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In contrast to the team's previous coatings, which are held together by ionic bonds, this coating is covalently bonded
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As such, Grunlan Labs speculates that it will be waterproof—and thus durable—perhaps antifungal and waterproof as well
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Industrial users can use this coating on building materials such as dowels and other framing, or oriented strand board (an engineered wood similar to particle board)
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Homeowners can use knapsack sprayers to protect current structures, such as barns or fences, that have been shown to spread wildfires, Thomas Kolibaba said
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Other possible applications include polyurethane foams and textiles for household goods, apparel, and the aerospace and automotive sectors, Grunlan Labs said
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Kolibaba added that UV-cured polyelectrolytes can also be used as a resin to make 3D printed parts, which are flammable when produced with conventional resins
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This could be a major advantage in aerospace, such as the International Space Station, he observed
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