Buildings meet a wide array of personal and societal needs but present large environmental challenges. They consume roughly 40 percent of US energy resources annually and 40 percent of carbon dioxide emissions. While certain materials are reused or recycled after their removal from service, most are landfilled as construction and demolition waste. Wood, plastics, and drywall make up a significant portion of construction and demolition waste. These materials are often used for short durations, are resistant to degradation in landfills, and are energy intensive to separate and recycle. Many can potentially be replaced by rapidly renewable and biodegradable (when out of service) materials. The aim of this project is to engineer a new class of fully recyclable rigid insulating material for buildings that contribute to energy-efficient building operations, improved indoor sound and potentially air quality, and have a high likelihood of adoption by the construction industry. Through the collaboration between University of North Texas and Stanford, a diverse cohort of undergraduate and graduate students will be educated. This research will be incorporated into relevant courses and online publically accessible learning modules. Furthermore, this project presents a curious topic to engage young minds in K-12 outreach programs.
The objective of this collaborative research project is to engineer a fully bio-resourced composite foam to achieve tunable concurrent thermal, acoustic and mechanical performance for building applications. The technical approach will combine the expertise of materials, chemical and structural engineers to (1) use renewable particulates to investigate the impact of particle size, shape and porosity on cellular formation of biocomposite foams, (2) explore interfacial chemistry of the particulates to impact particle-foam dispersion and cellular architecture, and (3) identify methods of using different polymers, blends and foaming conditions to achieve closed-cell and mixed open and closed-cell foams through a novel supercritical carbon dioxide batch processing method that is conducive to the fabrication of building-scale panels. The impact of moisture on thermal, acoustic and mechanical properties will also be investigated to understand in-service behavior. Performance metrics will initially target those of existing rigid insulating foams used in residential construction and will be extended to the evaluation of new material assemblies for building components. This research will (1) lead to new understanding of filler-polymer interactions, cell nucleation, bubble growth and their consequences on transport such as moisture, thermal and acoustic phenomena, (2) advance understanding of fully bio-based materials in cellular structures that are vital to all areas of lightweight and functional materials, and (3) offer renewable alternatives to fields where cellular structures find multiple uses ranging from biomedical to transportation as well as building science.
