Cardiff University | Prifysgol Caerdydd ORCA
Online Research @ Cardiff 
WelshClear Cookie - decide language by browser settings

Investigating the effects of processing, morphology and functionalisation on the properties of epoxy nanocomposites

Sangha, Perminder 2021. Investigating the effects of processing, morphology and functionalisation on the properties of epoxy nanocomposites. PhD Thesis, Cardiff University.
Item availability restricted.

[thumbnail of PhD Thesis]
Preview
PDF (PhD Thesis) - Accepted Post-Print Version
Download (52MB) | Preview
[thumbnail of Electronic thesis and dissertation form] PDF (Electronic thesis and dissertation form) - Supplemental Material
Restricted to Repository staff only

Download (234kB)

Abstract

The exceptional mechanical properties of graphene make it an attractive choice for use in composite materials. In order to achieve optimised mechanical performance, good graphene dispersion and interfacial interactions between graphene and matrix must be achieved. As graphene has a tendency to preferentially interact with itself and form into agglomerates which are not bonded with the matrix material, leaving the production of good quality graphene nanocomposites challenging. This industrially led project performed in conjunction with Haydale Ltd, aims to further understand this behaviour and how processing parameters can be used to optimise overall properties. Plasma-functionalisation, performed through bespoke plasma treatment HDPlas®, has been utilised to attach chemically reactive, oxygen-based functional groups to the surface of the studied graphene. This has been performed at varied intensities to understand the improvement to both interfacial bonding and dispersion of graphene within epoxy resin. Dispersion state has been further examined through investigation of various high-shear mixing methods and durations, and changes have been correlated to mechanical performance with tensile and flexural tests. A range of methods to characterise dispersion state have been explored to assess the efficacy of each method and suitability of use as a quality control process. Furthermore, DMA analysis has been employed to understand the effect of graphene, functionalisation and dispersion state on the cure behaviour and thermomechanical properties of the produced graphene / epoxy composite. The relationship between all of these factors has been assessed to produce an optimised mixing and manufacturing procedure. Investigations into the ‘shelf-life’ of dispersion state have also been performed, in order to assess any re-agglomeration behaviour after mixing. The use of various storage conditions have been investigated to assess the ability to preserve dispersion state. This work has shown a strong correlation between manufacturing parameters, dispersion state and mechanical properties and proposing an effective numerical method of predicting de�agglomeration. A full review of quality control methods determined macroscale techniques, which are easily incorporated into production lines, can successfully demonstrate dispersion state. The presence of functionalisation has been proven to improve mechanical properties and aid dispersion. The presence of graphene has been shown to alter the epoxy curing process, negatively impacting thermomechanical properties. Finally, storing materials at low temperatures was found to be most effective at preserving dispersion state.

Item Type: Thesis (PhD)
Date Type: Completion
Status: Unpublished
Schools: Engineering
Date of First Compliant Deposit: 23 December 2021
Last Modified: 23 Dec 2021 10:57
URI: https://orca.cardiff.ac.uk/id/eprint/146289

Actions (repository staff only)

Edit Item Edit Item

Downloads

Downloads per month over past year

View more statistics