07/09/2024
By Danielle Fretwell
Candidate Name: Daniyal Shoukat
Degree: Doctoral
Defense Date: July 19
Time: 11 a.m.- 1 p.m.
Location: Southwick, Room 204
Committee:
Advisor: Nese Orbey, Associate Professor, Chemical Engineering, University of Massachusetts Lowell
Committee Members*
1. Zhiyong Gu, Professor, Chemical Engineering, University of Massachusetts Lowell
2. Ravi Mosurkal, Co-Director HEROES, US Army DEVCOM Soldier Center, Natick
3. Ramaswamy Nagarajan, Professor, Plastics Engineering, University of Massachusetts Lowell
4. Jay Park, Assistant Professor, Plastics Engineering, University of Massachusetts Lowell
Brief Abstract:
This work consists of two sections. In the first section, mechanical properties of multi-material samples 3D printed using Fused Filament Fabrication (FFF) are studied. Multi-Material 3D printing is a promising method of integrating the functional properties of two dissimilar materials into a single end-part, and finds applications in the biomedical and electronics industries, especially for prototyping purposes. Poor mechanical performance of FFF printed parts resulting from insufficient interlayer bonding, however, hinders its use to print fully functional parts. It is therefore important to understand how the mechanical properties and interlayer bonding of multi-material parts are affected by material properties and 3D printing conditions. In this work, the mechanical properties of multi-material parts 3D printed using neat + reinforced poly(carbonate) or poly(lactic acid) + poly(caprolactone) are obtained and compared using two methods: 1) ASTM-based uniaxial tensile testing and 2) High Throughput Mechanical Analysis, as the extrusion temperature, layer thickness and volume composition of the filament are changed.
In the second section, multi-functional military fabrics (camo NyCo) having insect repellent (IR) and flame-retardant (FR) properties are developed using two approaches. Firstly, insect repellent microcapsules, previously developed in our group, consisting of a plant-based natural IR, geraniol, are covalently bonded to FR and Glycidyloxy-Propyl Trimethoxy Silane (GPTMS) functionalized fabrics. Microencapsulation is used to provide a controlled release of geraniol and prolong its insect repellency over a longer period. Chemical attachment of the IR microcapsules on fabrics is studied using FTIR and by evaluating the wash durability of the fabrics. Secondly, the synthesis of FR+IR multi-functional microcapsules, encapsulating geraniol and phosphorous-based FR, for chemical attachment on NyCo fabrics is demonstrated.