The research objective of this award is to conduct fundamental investigations towards the determination of the manufacturing-structure-property relationships in multifunctional polymer nanocomposites manufactured through selective laser sintering, with the ultimate goal of creating a new rapid and tool-less manufacturing technology for polymer nanocomposite components. Multifunctional polymer nanocomposites aimed at simultaneous improvements in mechanical, thermal and electrical performance will be prepared, characterized and modeled. The approach will be to integrate carbon nanomaterials (carbon black and graphite nanoplatelets) with unique electrical and thermal properties into an engineering thermoplastic polymer matrix (Nylon 12), advanced material processing through selective laser sintering, nanostructure characterization, and theoretical modeling of material processing and resulting properties. A systematic experimental and theoretical approach will be pursued to reveal the heat transfer and densification mechanisms in the selective laser sintering processing of polymer nanocomposites. The potential of the selective laser sintering process as a rapid, tool-less, manufacturing method for producing multifunctional polymer nanocomposites will be determined via a benchmark comparison with conventional polymer processing methods such as melt compounding with compression or injection molding. The proposed research will establish the scientific and technical basis for low-cost manufacturing of polymer nanocomposite components with complex three-dimensional geometries and with functionally graded properties.
If successful, the benefits of this research will include manufacturing of low-cost, light weight, thermally and electrically conductive multifunctional materials leading to new technologies and applications in the computing, communications, electronics, automotive, aerospace, and defense industries. Additionally, this research will provide commercially viable advanced manufacturing methods for polymer nanocomposites offering improved manufacturability and cost reductions over conventional processing methods; and potential of technology transfer to a start-up company through Georgia Tech?s Advanced Technology Development Center. Finally, significant benefits of this research will be the integration of teaching and outreach programs across multiple disciplines, including freeform fabrication and nanomaterials, to impact the education and training of a diverse student body at Georgia Tech; and the engagement of Dekalb County high school teachers and students in outreach activities involving hands-on exposure to advanced materials and manufacturing.
The outcomes/findings of this project can be summarized as follows: Provides fundamental understanding of the heat transfer and densification mechanisms of the selective laser sintering (SLS), an additive manufacturing process, for making electrically and thermally conductive polymer nanocomposites (PNCs). The important processing parameters and material properties which can lead to PNCs with engineered performance were identified. Demonstrates that SLS is an effective method for manufacturing of multifunctional polymer nanocomposites. The term multifunctional indicates that the composites in addition to satisfactory mechanical performance (flexural, see Fig, and tensile properties and impact strength) exhibit also functional properties such as electrical conductivity see Fig. Provides unprecedented insights into the processing-structure-property relationships of PNCs produced via SLS through comprehensive experimental studies. Provides one-to-one comparison of the melt mixing, injection molding, which is the traditional manufacturing process for thermoplastic polymer nanocomposites, and SLS by making PNCs using the two methods and comparing them in terms of their properties, see Fiures. The composites were made using PA 12 and exfoliated graphite nanoplatelets but the results/conclusions of the study can be generalized for all semi-crystalline thermoplastic polymers and thermally conductive nano-scale reinforcements. Enables low-cost, light weight, thermally and electrically conductive multifunctional materials leading to new technologies and applications in the computing, communications, electronics, automotive, aerospace, and defense industries.
