Toplinska svojstva kompozita s PLA matricom

master's thesis

• Title (english): Thermal properties of composites with poly(lactic acid) matrix
• Author: Katarina Brzić
• Mentor: Marica Ivanković (mentor)
• Committee member: Marica Ivanković (predsjednik povjerenstva)
• Committee member: Krešimir Košutić (član povjerenstva)
• Committee member: Anamarija Rogina (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2024-09-27, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract

Poli(mliječna kiselina) (PLA), alifatski je poliester izgrađen od monomera mliječne kiseline. Zbog svojih dobrih svojstava te biokompatibilnosti pronašla je primjenu u brojnim aplikacijama, među najvažnijima u medicini. PLA podložna je brojnim mehanizmima razgradnje kao što su hidroliza, mikrobiološka, fotokemijska, toplinska i enzimska razgradnja. Ipak, najvažniji mehanizam razgradnje PLA je hidroliza koja se temelji na kidanju esterskih veza u PLA te cijepanju polimernih lanaca, ulasku vode u strukturu te zatim na razgradnji oligomera do mliječne kiseline i u konačnici do vode i ugljikovog dioksida. Cilj ovog istraživanja bio je pratiti hidrolitičku razgradnju poli(mliječne kiseline) – (tehničkog-PLA, medicinskog praha-PLA i medicinskog filamenta-PLA) koja se koristi kao polimerna matrica kompozitnih materijala. Eksperimenti su provedeni u mediju koji simulira fiziološki sastav, kako bi se oponašali uvjeti u ljudskom tijelu tijekom vremenskog razdoblja od dva, četiri, šest i osam tjedana. Istražen je utjecaj hidrolitičke razgradnje na strukturu i svojstva PLA matrice. Karakterizacija uzoraka prije i nakon razgradnje provedena je pomoću diferencijalne pretražne kalorimetrije (DSC), pretražne elektronske mikroskopije (SEM) i mjerenja promjene mase. Ova analiza omogućila je detaljan uvid u toplinska svojstva, morfološke promjene i gubitak mase PLA matrice tijekom razgradnje, pružajući važne informacije o njenoj otpornosti i potencijalnoj primjeni u medicinskim uređajima i biomedicinskim aplikacijama.

Abstract (english)

Poly(lactic acid) (PLA) is an aliphatic polyester made of lactic acid monomers. Because of good properties and biocompatibility, PLA found its use in many applications, most importantly in medicine. PLA is prone to several degradation mechanisms, such as hydrolysis, microbiological, photochemical, thermal and enzymatic degradation. However, the most important PLA degradation mechanism is hydrolysis which is based on the cleavage of the ester bonds initiated by the diffusion of water in the PLA structure, then degrading from oligomers to lactic acid and ultimately to water and carbon dioxide. The aim of this research was to follow the hydrolytic degradation of poly(lactic acid) composites – based on technical-grade PLA, medical-grade PLA powder and medical-grade PLA filament. Experiments were conducted in media that simulate the physiological environment so it can imitate human body conditions during the period of two, four, six and eight weeks. The influence of hydrolytic degradation on the structure and properties of composites with PLA-matrix was investigated. Characterization of samples before and after degradation was made by Differential Scanning Calorimetry (DSC), Scanning Electron Microscope (SEM), and measuring change of mass. This analysis provided a detailed view into thermal properties, morphological changes and mass loss of composites throughout degradation, giving important information about their resistance and potential use in medical instruments and biomedical applications.

• Keywords: PLA matrica; hidrolitička razgradnja; struktura; toplinska svojstva
• Keywords (english): PLA-matrix; hydrolytic degradation; structure; thermal properties
• Language: croatian
• URN:NBN: urn:nbn:hr:149:484415
• Project: Number: KK.01.1.1.07.0014; Title: Biorazgradive 3D tiskane strukture za augmentaciju kosti; Title: Biodegradable 3D printed structures for bone augmentation; Acronym: BIDEAS; Leader: Hrvoje Ivanković; Jurisdiction: eu; Funder: Europska unija; Funding stream: European Regional Development Fund
• Study programme: Title: Applied Chemistry - Graduate study; specializations in: Environmental chemistry and green technologies, Advanced materials and technologies, Applied organic chemistry; Course: Applied organic chemistry; Study programme type: university; Study level: graduate; Academic / professional title: sveučilišni/a magistar/magistra primijenjene kemije (sveučilišni/a magistar/magistra primijenjene kemije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2024-11-07 11:49:12