07/23/2024
By Danielle Fretwell

The Francis College of Engineering, Department of Mechanical Engineering, invites you to attend a Doctoral Dissertation defense by Sourabh Kulkarni on "Flame Retardant and Multi-Functional Fabrics Enabled by Bio-inspired Materials."

Candidate Name: Sourabh Kulkarni
Degree: Doctoral
Defense Date: Aug. 2, 2024
Time: 1 to 3 p.m.
Location: DAN 220

Committee:

  • Advisor: Prof. Ertan Agar, Associate Professor, Department of Mechanical Engineering, UMass Lowell
  • Co-Advisor: Prof. Ramaswamy Nagarajan, Distinguished University Professor, Department of Plastics Engineering, UMass Lowell
  • Murat Inalpolat, Associate Professor, Department of Mechanical Engineering, UMass Lowell
  • Jayant Kumar, Professor, Department of Physics and Applied Physics, UMass Lowell
  • Ravi Mosurkal, US Army DEVCOM Soldier Center
  • Alexander B. Morgan, University of Dayton Research Institute

Brief Abstract:
Fabrics offer the first line of defense and protection against various environmental, thermal, and biological hazards that are both natural and man-made. Modern-day fabrics are typically made from a blend of fibers, consisting of natural and synthetic polymers. Blending various types of fibers to create fabric allows manufacturers to impart a combination of properties, including mechanical durability, stretch, and comfort. One such blend, commonly used by the Department of Defense globally, is Nyco, a 50% nylon 66 and 50% cotton blend currently used for manufacturing army combat uniforms. While Nyco demonstrates promising mechanical properties and comfort, it is flammable and lacks protection against microbes and insects, crucial functionalities for both defense and certain civilian populations.

This doctoral study aims to develop sustainable technologies to impart multifunctional characteristics to fabrics, including flame retardancy and antimicrobial properties. It is known that the survival of sequoia trees through forest fires is possible due to the presence of polyphenolic compounds such as tannic acid in the bark of these trees. Additionally, the husk (outer shell) of various seeds is rich in a phosphorus-containing compound called phytic acid, which is also produced in large quantities as a waste product of many food processing industries. The first part of this research involves the use of tannic acid and phytic acid to impart flame-retardant characteristics to Nyco fabric. Detailed thermal and flammability characterization was performed using thermogravimetric analysis, pyrolysis combustion flow calorimetry, cone calorimetry, and vertical flame testing to evaluate the performance of the treated fabrics.

The second part of the research involves the development of a new class of flame retardants for cotton fabrics with flame retardant characteristics that can be regenerated by washing in mild acids. These flame retardants can be recharged over repeated laundry cycles by a simple acid-scouring process. Detailed thermal and flammability testing and real-time evolved gas analysis during pyrolysis were carried out to establish the mechanism of FR action.

With growing concerns related to the spread of diseases and infections from microbes and viruses, it has become important to develop technologies that can impart protection against these threats. This research also covers the development of multifunctional Nyco fabrics with flame retardant and antimicrobial properties. A two-step method was developed to impart these properties to Nyco. The treated fabrics were tested for their flammability and antimicrobial properties. It was observed that the presence of antimicrobial agents did not inhibit the flame retardant properties. The mechanism of flame retardant action was also studied based on the evolved gas analysis of pyrolyzed products and smoke production during cone calorimetry. The treated fabrics were found to be self-extinguishing in a vertical flame test and showed up to a 2-log reduction in bacterial growth rate for both gram-positive and gram-negative bacteria.

All interested students and faculty members are invited to attend the defense in person or via MS Teams.