Binarne zelene mješavine kukuruznog termoplastičnog škroba s poli(3-hidroksibutirat-ko-3-hidroksivalerat)-om

master's thesis

• Title (english): Binary green blends of corn thermoplastic starch (TPS) with poly(3-hydroxybutyrate-co-3-hydroxyvalerate)
• Author: Mihael Barišić
• Mentor: Vesna Ocelić Bulatović (mentor)
• Committee member: Vesna Ocelić Bulatović (predsjednik povjerenstva)
• Committee member: Iva Movre Šapić (član povjerenstva)
• Committee member: Andrej Vidak (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2024-06-28, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Interdisciplinary Technical Sciences

Abstract

Stalni porast sintetske plastike u okolišu stvara hitnu potrebu za novim, biorazgradljivim materijalima. Polihidroksialkanoati (PHA) su se nedavno istaknuli kao obećavajući kandidati, posebno poli(3-hidroksibutirat-ko-3-hidroksivalerat) (PHBV). PHBV je biorazgradljivi polimer s dobrim mehaničkim svojstvima i velikim potencijalom za zamjenu tradicionalne plastike iz fosilnih goriva. Međutim, njegova visoka tržišna cijena ograničava širu primjenu. Ovaj rad se fokusira na pripremu biomaterijala na bazi PHBV-a i termoplastičnog škroba (TPS). TPS je pripremljen metodom lijevanja uz korištenje glicerola kao plastifikatora. Mješavine TPS-a i PHBV-a pripremljene su u Brabender gnjetilici, a potom su analizirana njihova, morfološka, toplinska,mehanička i barijerna svojstva. Diferencijalna pretražna kalorimetrija (DSC) korištena je za određivanje faznih prijelaza, dok je termogravimetrijska analiza (TGA) provedena radi uvida u toplinsku stabilnost materijala. Osnovna mehanička svojstva, prekidno naprezanje i prekidno istezanje, ispitana su na mehaničkoj kidalici. Uvid u morfologiju proveden je pretražnim elektronskim mikroskopom (SEM), dok je propusnost vodene pare određena Herfeldovom metodom.. DSC analiza ukazuje na djelomičnu mješljivost TPS/PHBV polimernih mješavina, što je vidljivo iz pomaka temperature staklišta pojedine komponente. TGA analizom potvrđeno je da se sve TPS/PHBV polimerne mješavine razgrađuju u dva stupnja: prvi stupanj odnosi se na razgradnju toplinski manje stabilnog PHBV-a, dok drugi stupanj obuhvaća razgradnju toplinski stabilnijeg TPS-a. Mehanička ispitivanja pokazala su da se vrijednosti prekidne čvrstoće TPS/PHBV polimernih mješavina nalaze između vrijednosti čistih komponenti TPS-a i PHBV-a. Vrijednosti propusnosti vodene pare TPS/PHBV polimernih mješavina također su smještene između vrijednosti propusnosti vodene pare izmjerenih za čiste komponente. SEM analizom dodatno je potvrđena djelomična mješljivost TPS/PHBV polimernih mješavina.

Abstract (english)

The continuous increase of synthetic plastics in the environment creates an urgent need for new, biodegradable materials. Polyhydroxyalkanoates (PHA) have recently emerged as promising candidates, especially poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV). PHBV is a biodegradable polymer with good mechanical properties and great potential to replace traditional fossil fuel-based plastics. However, its high market price limits its wider application. This work focuses on the preparation of biomaterials based on PHBV and thermoplastic starch (TPS). TPS was prepared using the casting method with glycerol as a plasticizer. TPS and PHBV blends were prepared in a Brabender kneader, and their morphological, thermal, mechanical, and barrier properties were analyzed. Differential scanning calorimetry (DSC) was used to determine phase transitions, while thermogravimetric analysis (TGA) was conducted to gain insight into the thermal stability of the materials. Basic mechanical properties, tensile strength, and elongation at break were tested using a mechanical testing machine. Morphology was examined using a scanning electron microscope (SEM), and water vapor permeability was determined using the Herfeld method. DSC analysis indicates partial miscibility of TPS/PHBV polymer blends, as evidenced by the shift in the glass transition temperature of each component. TGA analysis confirmed that all TPS/PHBV polymer blends decompose in two stages: the first stage corresponds to the decomposition of the thermally less stable PHBV, while the second stage involves the decomposition of the thermally more stable TPS. Mechanical tests showed that the tensile strength values of TPS/PHBV polymer blends fall between those of the pure components TPS and PHBV. The water vapor permeability values of TPS/PHBV polymer blends also fall between the water vapor permeability values measured for the pure components.
SEM analysis further confirmed the partial miscibility of TPS/PHBV polymer blends.

• Keywords: polihidroksialkanoati (PHA); poli(3-hidroksibutirat-ko-3-hidroksivalerat) (PHBV); termoplastični škrob (TPS); TPS/PHBV polimerne mješavine
• Keywords (english): polyhydroxyalkanoates (PHA); poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV); thermoplastic starch (TPS); TPS/PHBV polymer blends
• Language: croatian
• URN:NBN: urn:nbn:hr:149:624187
• Study programme: Title: Materials Science and Engineering - Graduate study; Study programme type: university; Study level: graduate; Academic / professional title: sveučilišni/a magistar/magistra inženjer/inženjerka kemijskog inženjerstva (sveučilišni/a magistar/magistra inženjer/inženjerka kemijskog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Embargoed access; Embargo expiration date: 2024-07-15
• Created on: 2024-07-03 11:07:03