04/29/2022
By Sokny Long
Ph.D. Student: Ninad Khadse
Defense Date: Monday, May 9, 2022
Time: 11 a.m. to 12:30 p.m.
Location: In person, at Perry Hall 215. This will also be a virtual defense via Zoom. Those interested in attending should contact ninad_khadse@student.uml.edu and committee advisor, Jay_Park@uml.edu, at least 24 hours prior to the defense to request access to the meeting.
Committee Chair (Advisor): Jay Park, Ph.D., Assistant Professor, Plastics Engineering, University of Massachusetts Lowell
Committee Members:
• Ramaswamy Nagarajan, Ph.D., Professor, Plastics Engineering, University of Massachusetts Lowell
• Akshay Kokil, Ph.D., Assistant Teaching Professor, Plastics Engineering, University of Massachusetts Lowell
• Hongwei Sun, Ph.D., Professor, Mechanical and Industrial Engineering, Northeastern University
Brief Abstract: Novel self-crimping polyester fibers in a side-by-side configuration based on mismatching modulus and coefficient of thermal expansion (CTE) between the two fiber components are fabricated by bicomponent melt-spinning; the filament fibers will be primary constituents for either knitted or nonwoven fabrics that can provide dynamic thermal insulation in the temperature range of -30 °C to 30°C. The two halves are made of Crastin, a polybutylene terephthalate resin, and Hytrel, a thermoplastic elastomer. The fibers were cold drawn at various draw ratios to study the effects on mechanical and thermal properties along with fiber morphology. All the fibers showed excellent interfacial adhesion as evidenced by absence of debonding during tensile tests which also showed an increase in modulus and decrease in elongation at break which was attributed to strain-induced orientation of the molecular chains during drawing. Thermal analysis using DSC showed increased crystallinity for the PBT melting peaks with higher draw ratio fibers and absence of cold crystallization for all the draw ratios indicated low amorphous content. Thermo-mechanical analysis on the fibers shows that the CTE increases with fiber diameter. When used as battings, these fibers could provide dynamic insulation based on ambient temperature which would result in fiber curvature and hence the amount of crimp in the fibers.
All interested students and faculty members are invited to attend the online defense via remote access.