Traitements au plasma à décharge de barrière diélectrique pour l'amélioration des propriétés de l'acide polylactique pour les applications biomédicales
|Abstract:||The objective of this project is to study the effects of plasma treatment on the surface characteristics and the in-vitro degradation properties of polylactic acid (PLA) for different applications such as biodegradable cardiovascular stents. Polymer films are treated by two different dielectric barrier discharge plasma. The carrier and oxidative gas mixtures in these reactors are argon+water vapor and nitrogen+nitrous oxide. Both the treated and non-treated PLA samples are characterized by X-ray photoelectron spectroscopy, atomic force microscopy, surface energy, and contact angle analysis. Additionally, the aging behavior of the surfaces after each treatment is investigated. In-vitro hydrolytic degradation studies are conducted by measurements of mass loss and molecular weight loss as a function of the incubation time. The results indicate that the PLA surface becomes more hydrophilic in all the treated samples. Increased hydrophilicity is associated with modifications to the chemical composition of the treated surfaces. Also, analysis of the surface morphology shows that the argon and water vapor plasma induces the formation of some nodule-like structures on the surface. All the treated surfaces undergo hydrophobic recovery to some extent due to the rearrangement of the polar groups into the bulk. Moreover, in-vitro degradation studies show that plasma treatments do not affect the PLA hydrolytic degradation properties.|
|Document Type:||Mémoire de maîtrise|
|Open Access Date:||19 July 2021|
|Collection:||Thèses et mémoires|
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