LIT 3: Primer-Less Self-Healing Sealant

Building envelopes have air and water barrier systems that prevent the intrusion of air and moisture that lead to higher energy use, moisture durability problems, and/or damages to interior surfaces. A key element in these systems are sealants that seal numerous joints. Although there are a wide variety of sealants in the market, adhesion and cohesion failures persist. Thus, joints are among the most vulnerable locations in air and water barrier systems. To improve the air and water tightness of building envelopes, we are developing a new polymer-based sealant that will eliminate the need for a primer even in substrates with some contaminants, and that will self-heal micro-cracks and cuts in the sealant. Our new primer-less self-healing (PLSH) sealant will achieve a peel strength ³25 lb/in; and will recover its elasticity, modulus, and toughness after £30 minutes of self-healing. Therefore, the PLSH sealant will have better performance and longer life expectancy than current products. Simulation results indicate that using our sealant to retrofit and improve the airtightness in 50% of homes and 20% of commercial buildings could lead to annual energy savings of 280 TBtu.

Self-healing polymer elastomer that we recently developed. The top images show a test sample that we cut into two pieces and let self-heal after allowing the pieces to touch each other. The middle and bottom images demonstrate how the polymer recovered some of its stretchability after 15 minutes of healing.

Innovators

Diana E. Hun

Oak Ridge National Laboratory

Diana Hun is the Subprogram Manager for Building Envelopes at Oak Ridge National Laboratory. Her research includes investigating the integration of the latest developments in materials and manufacturing techniques into building envelopes. For instance, she leads several interdisciplinary teams that are developing primer-less self-healing sealants, the next generation of precast insulated panels, and polymeric vacuum insulation spheres. Other research areas include improving the airtightness of buildings while minimizing risks due to potential building material deterioration and indoor air quality problems. Hun received a PhD in Civil Engineering from The University of Texas at Austin with a grant from the National Science Foundation.

Tomonori Saito

Oak Ridge National Laboratory

Tomonori Saito is a synthetic polymer chemist at Oak Ridge National Laboratory (ORNL). Saito has extensive knowledge in the synthesis of well-defined polymers via living/controlled polymerization as well as post-modification of various polymers. His expertise has been applied to various projects at ORNL including CO2 separation membranes, flow battery, ion-conducting polymers for batteries and battery binders, ionic liquid polymers, polymer nanocomposites, additive manufacturing, polymer nanoparticles, elastomers, self-healing materials, uranium extraction from seawater, polyolefin-based carbon fibers, lignin based-carbon fibers, and lignin- based novel renewable thermoplastics. Saito has published 68 peer-reviewed articles, has 4 patents, and won R&D100 awards in 2012 and 2016. Saito received his PhD in Chemistry from Virginia Tech.

Page updated

Report abuse