This BRIGE project will seek routes to improved thermophysical properties for renewable polymers through the formation of nanocomposites. The viability of renewable plastics depends on low-cost processing and expansion of the thermomechanical properties for a broad range of applications. The objective of the research is to understand the effects of novel high-speed extrusion processing of nanocomposites with renewable polymer matrices. Conventional twin screw extrusion reaches rotation speeds of 400 rpm, but next-generation extruders are now available that can achieve 4500 rpm. Extrusion blending at these high speeds has the potential to transform understanding of nanocomposite processing. Application of high shear can also degrade sensitive renewable polymers, so the limits to this technique must be explored. This work will also relate the effects of surface functionalization to rheological and structural properties of the nanocomposites to deduce the mechanisms of interfacial toughening. Theoretical findings relating enthalpic interactions, dispersion and reinforcement are more broadly applicable to other polymer-nanoparticle systems. The intellectual merit of the proposed research will be provided through: (1) potentially transformative capabilities of the new extrusion mixing technology, (2) quantitative understanding of the roles of interfacial interactions and dispersion in nanocomposite polymer reinforcement including a rheological model of processing properties, and (3) foundational knowledge on processing behavior of renewable polymers.
Broader Significance and Importance:
The project will have broader impacts on society through its focus on sustainable materials, education of the next generation of scientists, and broadening participation of women in engineering. The new paradigm for reinforcement of polymers from renewable resources will accelerate their route to commercialization. The improved particle dispersion achieved through high-speed mixing will lead to lighter, stronger and more sustainably manufactured nanocomposites. Knowledge gained on the novel processing technique will be applicable to a range of multicomponent materials. Integration of research and education will be accomplished through a "teach the teachers" pilot program that provides polymers-focused experimental examples for area high school teachers. An important focus of this project is to broaden participation of women in engineering, specifically addressing attrition from college entry to the professional workplace.
Broadening Participation:
The broadening participation objective of this project is to create mentorship networks among women at multiple engineering career and academic levels. Interactive discussions at high school technical programs will establish a supportive mentorship network among female students interested in engineering. The success of the cooperative training program at UMass Lowell will be leveraged for sharing of career experiences among student groups. Participating students will have the opportunity to observe and model success in all stages of the engineering career. The integrated educational and outreach activities with area high schools and vocational programs will provide opportunities in engineering for at-risk students and increase retention among female engineering students at the outset of their careers.
This research has been funded through the Broadening Participation Research Initiation Grants in Engineering solicitation, which is part of the Broadening Participation in Engineering Program of the Engineering Education and Centers Division.
