Date of Award

2023-05-01

Degree Name

Master of Science

Department

Metallurgical and Materials Engineering

Advisor(s)

David A. Roberson

Abstract

The purpose of this work is to incorporate additive manufacturing technology (AM) in the development of shape memory polymer blends. Two polyester blend systems were developed, one binary and the other ternary. The binary blend consisted of polycaprolactone (PCL) and thermoplastic polyurethane (TPU) and the ternary blend was composed of PCL, TPU and polylactic acid (PLA). Test specimens were fabricated with the AM technology of fused filament fabrication (FFF). Several tests were performed to characterize the mechanical and shape memory properties. A dynamic mechanical analyzer (DMA) was first used to establish the shape recovery temperature. Tensile testing was carried out to determine the ultimate tensile strength (UTS) an % elongation (%El) values. Tensile testing was also used to determine the critical shape memory [properties, namely the shape recovery ratio (Rr) and shape fixation ratio (Rf). A key aspect of this work also involves the emerging materials science premise of high entropy materials and demonstrates how ternary blends can open the way for high entropy shape memory polymers. The shape memory performance of the two blend systems is also compared. This work also explores the self-healing capability of TPU/PCL and TPU/PCL/PLA blend systems. Additionally, the effect of raster pattern on the mechanical and shape memory properties is also made. Scanning electron microscopy (SEM) was used to perform fracture surface analysis and a difference between material type and raster pattern was also made.

Language

en

Provenance

Recieved from ProQuest

File Size

p.

File Format

application/pdf

Rights Holder

Luis Eduardo Lares Carrillo

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Engineering Commons

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