Grantee Research Project Results
Final Report: Environmentally Friendly Flame Retardants Based on Inorganic Nanosheets
EPA Grant Number: SU835705Title: Environmentally Friendly Flame Retardants Based on Inorganic Nanosheets
Investigators: Bendel, Brittany A , Masinda, William C , Chavez, Sonia E , Nguyen, Tu GT , Kavacs, Lauren M , Havasov, Arie , Yu, Jingfang , Liu, Jingjing , Sun, Luyi , Zeng, Songshan , Wang, Zhaofeng
Institution: University of Connecticut
EPA Project Officer: Hahn, Intaek
Phase: I
Project Period: August 15, 2014 through August 14, 2015
Project Amount: $15,000
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet (2014) RFA Text | Recipients Lists
Research Category: Pollution Prevention/Sustainable Development , P3 Challenge Area - Chemical Safety , P3 Awards , Sustainable and Healthy Communities
Objective:
Flame retardants play a critical role in fire prevention, helping save life and properties, but they have also generated significant environmental concerns. Some of current commercial flame retardants (such as halogenated flame retardants) naturally release toxic active flame retardant components, as well as generate toxic gases during combustion, leading to significant health and safety issues. Such toxic chemicals have spread to the entire world, and are associated with a number of health problems. Therefore, theobjectiveof this project is to develop anenvironmentally friendlyand cost effective flame retardant based on inorganic nanosheets, which can exhibit similar or higher flame retardancy performance but without such environmental issues.
Specifically, we aim to develop a novel waterborne halogen-free flame retardant nanocoating composed of hundreds of layers of well aligned inorganic nanosheets, which can physically block heat/oxygen transmission and thus effectively retarding flames. The waterborne nature ensures that no volatile organic compounds (VOCs) will be released during coating formation process. This nanocoating will be formed via one-step co-assembly of inorganic nanosheets and polymer binders from their aqueous dispersion and thus can be operated continuously. It involves the co-assembly of nanosheets with a selected polymer, which possesses weak interactions (such as electrostatic force, hydrogen bonding, etc.) with the nanosheets. In this way, in the aqueous dispersion system, the selected polymer chains can attach to the inorganic nanosheets surface. During the subsequent co-assembly process, the nanosheets can be well aligned by either gravity or a physical force exerted by common industrial processing tools, with the polymer serving as the binder of the nanosheets to form a hybrid nanocoating with a highly ordered layered structure, leading to outstanding flame retardancy. Because this new flame retardant nanocoating is based on the physical shielding of hundreds of layers of well-aligned inorganic nanosheets that are inherently not flammable, this new flame retardant nanocoating will release minimum chemicals during combustion. Most importantly, there will be no natural release of toxic compounds from this flame retardant nanocoating as it does not contain such components. As such, replacing halogenated flame retardants by this environmentally friendly flame retardant nanocoating can effectively prevent the current environment and health issues associated with the halogenated flame retardants.
Summary/Accomplishments (Outputs/Outcomes):
The prepared nanocoating consists of a natural clay, montmorillonite (MMT), and polyvinyl alcohol (PVA), possessing outstanding oxygen barrier and flame retardancy. With a very thin nanocoating, the coated polyethylene terephthalate (PET) film (22 µm) remained its original shape after 30 seconds of vertical combustibility testing (see Figure 7 in report and related videos). The coated open-cell polyurethane (PU) foam can virtually maintain its original shape after 10 seconds of horizontal combustibility testing (see Figure 9 in report and related videos). In addition, the nanocoating exhibits outstanding mechanical properties and high transparency.
Such merits are beneficial for practical applications.
Conclusions:
We have successfully developed an environmentally friendly flame retardant nanocoating. Thanks to its waterborne nature, no VOCs or other toxic chemicals were released during coating formation process. Because this nanocoating is composed of inorganic nanosheets and PVA, it does not release any toxic flame retardant components, nor generates toxic gas during combustion. This flame retardant nanocoating exhibits superior
Journal Articles on this Report : 1 Displayed | Download in RIS Format
Other project views: | All 5 publications | 1 publications in selected types | All 1 journal articles |
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Ding F, Liu J, Xia Y, Wells KM, Nieh MP, Sun L. Biomimetic nanocoatings with exceptional mechanical, barrier, and flame-retardant properties from large-scale one-step coassembly. Science Advances 2017;3(7):e1701212, |
SU835705 (Final) |
Exit Exit |
Supplemental Keywords:
environmentally benign substitute, green chemistry, nanotechnology, global considerationRelevant Websites:
Links for combustibility test of samples:
Uncoated PET film (control) Exit
Uncoated PU foam (control) Exit
The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.