Term of Award

Spring 2024

Degree Name

Master of Science, Applied Physical Science

Document Type and Release Option

Thesis (open access)

Copyright Statement / License for Reuse

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.

Department

Department of Chemistry and Biochemistry

Committee Chair

Dr John DiCesare

Committee Member 1

Dr Rafael Quirino

Committee Member 2

Dr Xiao-Jun Wang

Abstract

Carbon nanotubes (CNTs), with their excellent mechanical properties, are well suited to the production of composites with good strength-to-weight ratio. However, the use of nanotubes as reinforcement is hampered by the lack of interaction between their inert surfaces and matrices. This, coupled with the van der Waal’s interactions between individual nanotubes, leads to agglomeration of CNTs in media. Functionalization is an efficient means to disperse nanotubes as well as increase their reactivity. The irradiation of CNTs with microwaves generates instantaneous, localized heating, being used in this work to trigger the rapid, thermal, free radical polymerization of styrene. Under microwaves, olefin-functionalized CNTs work as the heating source for the system, becoming the initial points for polymer chain growth during polymerization, as well as crosslink points within the polymer network. In this work, multi-walled carbon nanotubes (MW-CNTs) were covalently functionalized with three different groups: n-pentenyl, styrenyl, and phenyl. Pristine and functionalized CNTs were used as reinforcement during the production of CNT/polystyrene nanocomposites at 0.2 weight percent loading, in both conventional oven and microwave oven. The composites were characterized by thermogravimetry, differential scanning calorimetry, dynamic mechanical analysis, and tensile testing. n-pentenyl-functionalized CNTs showed the best dispersion while the addition of carbon nanotubes enhanced the mechanical properties of polystyrene. Composites from microwave-induced polymerization were more uniform than those made by conventional heating. Microwave-induced polymerization occurred five times faster than conventional heating. However, there was no statistically significant difference in mechanical properties between composites of pure and functionalized CNTs.

OCLC Number

1433044960

Research Data and Supplementary Material

Yes

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