(4hi) Material extrusion based additive manufacturing of semicrystalline polymers for multifunctional applications

Filament-based material extrusion (MatEx) additive manufacturing has garnered huge interest in both academic and industrial communities. Moreover, there is an increasing need to expand the material catalog for MatEx to produce end use parts for a wide variety of applications. Current approaches toward MatEx of semicrystalline thermoplastics are material and printer specific. MatEx of commodity semicrystalline thermoplastics such as, polyethylene and polypropylene, has been investigated but most of the current approaches are extremely material and machine specific.

The goal of the current research is to enable MatEx of semicrystalline polymers with mechanical properties and quality approaching injection molded parts. Tailored molecular architectures of blends that can retard the crystallization process from the melt, thereby allowing enhanced polymer chain mobility that leads to better interlayer adhesion is investigated. Modifications in the crystallization process significantly impact the z-axis adhesion and residual stress state, which directly affect mechanical properties and warpage in the printed parts. The impact of the blend composition on polymer chain diffusion from the repeated non-uniform thermal history in MatEx is studied. The melt flow behaviour is characterized using shear rheology and its effect on interlayer adhesion of the printed parts and print precision is explored. Tensile bars are printed and mechanically characterized to analyze the tensile performance of the printed parts. The research will help to identify the optimal processing conditions to maximize material specific printed part performance as well as highlight the limitations in processing conditions and indicate necessary modifications to enable MatEx of next generation materials.

Research Interests

My research interests lie in the fields of polymer processing and advanced manufacturing. I am currently involved with multiple research projects investigating additive manufacturing of semicrystalline polymers, rheology of polymer blends for 3D printing, composite processing, and environmental remediation using deployable 3D printed parts. I have experience in rheological characterizations, crystallization and thermal analysis of polymers.