Utjecaj procesa višestrukog mehaničkog recikliranja na svojstva polietilena visoke gustoće

undergraduate thesis

• Title (english): Effect of multiple mechanical recycling process on properties of high-density polyethylene
• Author: Helen Crnojević
• Mentor: Zvonimir Katančić (mentor)
• Committee member: Zvonimir Katančić (predsjednik povjerenstva)
• Committee member: Mirela Leskovac (član povjerenstva)
• Committee member: Danijela Ašperger (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2024-05-29, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract

Polimerni materijali od iznimne su važnosti zbog svoje velike primjene zbog koje se nalaze svuda oko nas. Upravo radi toga nastaju i velike količine polimernog otpada koji, ukoliko se ne zbrine može imati negativan utjecaj na ljude i okoliš. Jedan od načina zbrinjavanja polimernog otpada je mehaničko recikliranje istog. Mehaničko recikliranje pokazalo se kao učinkovit postupak prerade termoplastičnih polimernih materijala čime im se omogućava ponovno korištenje u iste ili druge svrhe, te se smanjuje količina ukupnog polimernog otpada. Kako je tijekom mehaničkog recikliranja, koje uključuje toplinsku preradu, moguće da dođe do određenog stupnja degradacije materijala u ovom radu ispitano je dolazi li do promjene svojstava polietilena visoke gustoće (HDPE) uslijed više ciklusa recikliranja. Uzorci su nakon provedenog mehaničkog recikliranja analizirani različitim metodama, toplinskim i spektroskopskim, kao i pomoću mehaničke kidalice, kako bi se ustanovilo dolazi li do promjene svojstava (degradacije) navedenog polimernog materijala uslijed mehaničkog recikliranja. Ukupno je provedeno 12 ciklusa mehaničkog recikliranja, a analizirani su uzorci HDPE-a nakon 3., 6., 9. i 12. ciklusa, te svježi HDPE. Pomoću infracrvene spektroskopije s Fourierovom transformacijom (FTIR) snimljeni su spektri uzoraka, pomoću kojih je izračunat karbonilni indeks (C.I.) kako bi odredilo dolazi li do degradacije. Toplinska svojstva su određena diferencijalnom pretražnom kalorimetrijom (DSC) i termogravimetrijskom analizom (TGA). Osim toga određen je i maseni protok taljevine (MFR), te su ispitana mehanička svojstva uzoraka pomoću mehaničke kidalice čime su dobiveni podaci o prekidnoj čvrstoći, prekidnom istezanju, te elastičnosti ispitanih uzoraka. Iz rezultata istraživanja došlo se do zaključka da višetruko mehaničko recikliranje nema značajan negativan utjecaj na kemijsku strukturu i svojstva polietilena visoke gustoće koji bi ograničio primjenu recikliranog HDPE-a odnosno mehaničko recikliranje učinkovita je metoda oporabe HDPE-a.

Abstract (english)

Polymeric materials are extremely important because of their wide range of applications, which is why they can be found all around us. For this very reason, large amounts of polymer waste are generated which, if not disposed of, can have a negative impact on people and the environment. One of the ways to dispose of polymer waste is mechanical recycling. Mechanical recycling has proven to be an effective way of processing thermoplastic polymers, enabling their reuse for the same or other purposes and reducing the total amount of polymer waste. Since mechanical recycling involving thermal processing can potentially cause some degree of material degradation, this study investigated whether the properties of high-density polyethylene (HDPE) change after multiple recycling cycles. Samples were analyzed after mechanical recycling using various methods, including thermal and spectroscopic techniques as well as mechanical testing, to determine whether the properties of this polymer material change (degrade) as a result of mechanical recycling. A total of 12 recycling cycles were performed and the HDPE samples were analyzed after the 3rd, 6th, 9th and 12th cycles as well as fresh HDPE. Fourier transform infrared spectroscopy (FTIR) was used to record the spectra of the samples, from which the carbonyl index (C.I.) was calculated to determine the degree of degradation. The thermal properties were characterized by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). In addition, the melt flow rate (MFR) was determined and the mechanical properties of the samples were tested using a universal testing machine, which provided data on the tensile strength, elongation at break and elasticity of the tested samples. From the research results, it was concluded that multiple mechanical recycling has no significant negative effects on the chemical structure and properties of high-density polyethylene, which would limit the use of recycled HDPE, i.e. mechanical recycling is an effective method of HDPE recycling.

• Keywords: polimerni materijali; mehaničko recikliranje; polietilen visoke gustoće (HDPE); degradacija materijala
• Keywords (english): polymer materials; mechanical recycling; high density polyethylene (HDPE); material degradation
• Language: croatian
• URN:NBN: urn:nbn:hr:149:686532
• Study programme: Title: Applied Chemistry - Undergraduate study; specializations in: Environmental chemistry and green technologies, Advanced materials and technologies, Applied organic chemistry; Course: Advanced materials and technologies; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) primijenjene kemije (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) primijenjene kemije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2024-06-12 08:23:56