Coarsening Dynamics in Co-Continuous Polymer Blends and Composites

Shah, Rajas Sudhir

Coarsening Dynamics in Co-Continuous Polymer Blends and Composites

dc.contributor.advisor	Trifkovic, Milana
dc.contributor.advisor	Bryant, Steven
dc.contributor.author	Shah, Rajas Sudhir
dc.contributor.committeemember	Karan, Kunal
dc.contributor.committeemember	Natale, Giovanniantonio
dc.contributor.committeemember	Wong, Joanna
dc.contributor.committeemember	Mohraz, Ali
dc.date.accessioned	2023-04-26T18:47:43Z
dc.date.available	2023-04-26T18:47:43Z
dc.date.issued	2023-04-18
dc.description.abstract	Co-continuous polymer blends find extensive use across multiple industries. However, the morphology of these blends is thermodynamically unstable, which causes coarsening during processing. As a result, it is essential to understand the coarsening mechanism to improve their performance. Unfortunately, the current literature lacks a comprehensive explanation of the microstructural changes that occur during coarsening. To address this issue, the study employs 4D laser scanning confocal microscopy coupled with rotational rheometry to observe the coarsening dynamics in real-time. The aim is to understand the interplay between viscoelasticity and morphology during coarsening. The results show that when the ratio of interfacial tension to viscosity of blends exceeds a critical value, they tend to break down into droplet-matrix structures. The study also focuses on improving the stability and functionality of blends by incorporating solid particles. In literature, particle surfaces are often chemically modified, requiring complex and costly treatments. Therefore, this study examines the stability of co-continuous blends with pristine particles and how particle size and size distribution affect the stability. The study investigates the coarsening dynamics of blends filled with five different silica particles of diameters ranging from 5 nm to 490 nm. The results show that particle size does not play a role in blend stability when particles are thermodynamically driven to their preferred polymer phase. However, a striking effect is achieved when particles are kinetically trapped at the interface. The interparticle interaction governs their extent of agglomeration and, consequently, their ability to stabilize the morphology. The most effective, 140 nm and 250 nm particles are then added into blends under different loading ratios to simulate polydispersity in four different blends. The study demonstrates that polydispersity in particle size does not negatively affect blend stability. The efficacy of particles to suppress coarsening is dependent on their initial localization in the blend, which is determined by polymer characteristics. Overall, the study's findings provide a better understanding of the coarsening mechanism and stabilization of co-continuous morphology in polymer blends using particles. The results contribute to the fundamental knowledge of these materials and can aid in improving their design in various industries.
dc.identifier.citation	Shah, R. S. (2023). Coarsening dynamics in co-continuous polymer blends and composites (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.
dc.identifier.uri	http://hdl.handle.net/1880/116108
dc.identifier.uri	https://dx.doi.org/10.11575/PRISM/dspace/40954
dc.language.iso	en
dc.publisher.faculty	Graduate Studies
dc.publisher.institution	University of Calgary
dc.rights	University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.
dc.subject	confocal microscopy
dc.subject	rheology
dc.subject	microstructure
dc.subject.classification	Engineering--Chemical
dc.subject.classification	Materials Science
dc.subject.classification	Plastics Technology
dc.title	Coarsening Dynamics in Co-Continuous Polymer Blends and Composites
dc.type	doctoral thesis
thesis.degree.discipline	Engineering – Chemical & Petroleum
thesis.degree.grantor	University of Calgary
thesis.degree.name	Doctor of Philosophy (PhD)
ucalgary.thesis.accesssetbystudent	I require a thesis withhold – I need to delay the release of my thesis due to a patent application, and other reasons outlined in the link above. I have/will need to submit a thesis withhold application.