Utjecaj višestrukih ciklusa mehaničkog recikliranja na otpuštanje aditiva iz polipropilenske mikroplastike

master's thesis

• Title (english): Effect of multiple mechanical recycling process on release of additives from polypropylene microplastics
• Author: Petra Soldo
• Mentor: Zvonimir Katančić (mentor)
• Committee member: Zvonimir Katančić (predsjednik povjerenstva)
• Committee member: Matija Cvetnić (član povjerenstva)
• Committee member: Josipa Papac Zjačić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2024-09-26, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract

Polimeri su temeljni materijali modernog društva, s polipropilenom (PP) kao jednim od najčešće korištenih termoplastičnih polimera zbog svoje fleksibilnosti, izdržljivosti i prilagodljivosti različitim primjenama. Dodavanje aditiva ključno je za poboljšanje mehaničkih svojstava polimernih materijala. Međutim, s porastom svjetske proizvodnje i upotrebe polimera raste i količina plastičnog otpada, što predstavlja veliki ekološki izazov. Mehaničko recikliranje često se promovira kao održivo rješenje za smanjenje plastičnog otpada. Iako termoplasti teoretski mogu izdržati više ciklusa recikliranja bez značajnog gubitka svojstava, malo je istraživanja posvećeno proučavanju utjecaja ovih procesa na otpuštanje aditiva, koji u obliku mikroplastike mogu dospjeti u okoliš. Cilj ovog rada je bio analizirati utjecaj višestrukog mehaničkog recikliranja na otpuštanje aditiva iz polipropilenske mikroplastike.
U tu svrhu pripremljena su dva uzorka. Prvi uzorak je se sastojao od polipropilena (PP) s dodanim antioksidansima i plastifikatorom, dok su drugom uzorku polipropilena (PP) dodani antioksidansi. Nakon pripreme, provedena je simulacija pet ciklusa mehaničkog recikliranja u laboratorijskom ekstruderu. Nakon svakog ciklusa recikliranja, uzorci su usitnjeni na veličinu mikroplastike. Karakterizacija uzoraka provedena je nakon 1., 3. i 5. ciklusa, kako bi se odredile promjene svojstava polipropilena uzrokovane migracijom aditiva. Metode karakterizacije uključivale su infracrvenu spektroskopiju s Fourierovom transformacijom (FTIR), termogravimetrijsku analizu (TGA) i diferencijalnu pretražnu kalorimetriju (DSC).
Ove metode omogućile su praćenje promjena u kemijskoj strukturi, toplinskim svojstvima i stupnju kristalnosti uzoraka polipropilena. Također praćene su i migracije aditiva iz mikroplastike u vodu, te je određena toksičnost vodenih uzoraka prema bakterijskoj kulturi Vibrio fischeri, omjer biorazgradivosti i sadržaj ukupnog organskog ugljika.

Abstract (english)

Polymers are fundamental materials in modern society, with polypropylene (PP) being one of the most widely used thermoplastic polymers due to its flexibility, durability and adaptability to various applications. The addition of additives is essential for improving the mechanical properties of polymer materials. However, with the increasing global production and use of polymers, the amount of plastic waste is also increasing, which represents a major environmental challenge. Mechanical recycling is often promoted as a sustainable solution to reducing plastic waste. Although thermoplastics can theoretically withstand multiple recycling cycles without significant loss of properties, little research has been devoted to studying the impact of these processes on the release of additives, which can end up in the environment in the form as microplastics. The aim of this work was to analyze the effects of multiple mechanical recycling processes on release of additives from polypropylene microplastic.
Two samples were prepared for this purpose. The first sample consisted of polypropylene with added antioxidants and plasticizer, while the second sample contained polypropylene with only antioxidant. After preparation, a simulation of five cycles of mechanical recycling were simulated in a laboratory extruder. After each recycling cycle, the samples were ground to microplastic size. Characterization of the samples was conducted after the 1st. 3rd and 5th cycles to determine changes in the properties of polypropylene caused by the migration of additives. Characterization methods included Fourier-Transform Infrared Spectroscopy (FTIR), Thermogravimetric analysis (TGA) and Differential Scanning Calorimetry (DSC). These methods allowed monitoring changes in the chemical structure, thermal properties, and crystallinity of the polypropylene samples. The migration od additives from microplastics into water was also monitored, and the toxicity of water samples according to Vibrio fischeri bacterial culture, biodegradability ratio and total organic carbon content were determined.

• Keywords: polimeri; mikroplastika; polipropilen; aditivi; mehaničko recikliranje
• Keywords (english): polymer; microplastics; polypropylene; additives; mechanical recycling
• Language: croatian
• URN:NBN: urn:nbn:hr:149:263102
• Project: Number: IP-2020-02-6033; Title: Mikroplastika u vodi; sudbina, ponašanje i uklanjanje; Title: Microplastics in water; fate and behavior and removal; Acronym: ReMiCRO; Leader: Ana Lončarić Božić; Jurisdiction: Croatia; Funder: Hrvatska zaklada za znanost; Funding stream: Research Projects
• 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: Open access; Embargo expiration date: 2025-02-01
• Created on: 2024-11-07 09:55:05