Utjecaj termooksidativnog starenja na PE i PET mikroplastiku

undergraduate thesis

• Title (english): Effect of thermooxidative ageing on PET and PE microplastics
• Author: Bruna Prusac
• Mentor: Marin Kovačić (mentor)
• Committee member: Ana Lončarić Božić (predsjednik povjerenstva)
• Committee member: Irena Ivanišević (član povjerenstva)
• Committee member: Marijana Kraljić Roković (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2023-09-19, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract

Velik porast potražnje za plastičnim proizvodima u posljednjim desetljećima doveo je do znatnih razmjera onečišćenja okoliša plastikom. Različitim procesima starenja i mehaničke degradacije plastika se postupno usitnjava na sitnije dijelove (<5 mm) i nastaje mikroplastika koja se smatra jednim od prioritetnih onečišćivala današnjice. Mikroplastika negativno utječe na sve sastavnice okoliša, a može imati i znatne posljedice na ljudsko zdravlje. U ovom radu polimeri poli(etilen-tereftalat) (PET) i polietilen visoke gustoće (HDPE), toplinski su stareni u laboratorijskoj peći iznad temperature taljenja. Uzorci polimera potom su usitnjeni do veličine mikroplastike te karakterizirani pomoću infracrvenog spektrofotometra s Fourierovom transformacijom signala koji koristi metodu atenuirane totalne reflektometrije (ATR-FTIR) i diferencijalnog pretražnog kalorimetra (DSC). Kod HDPE-a nisu vidljive značajne promjene između nestarenih i starenih uzoraka, zbog nedovoljno visoke temperature zagrijavanja koja je potrebna za inicijaciju toplinske degradacije. U starenim uzorcima PET-a vidljive su promjene u boji te dolazi do pogoršanja pojedinih svojstava poput temperature taljenja (Tm), temperature staklastog prijelaza (Tg), postotka kristalnosti (χ), i tako dalje. Iako su u PET uzorcima neke promjene vidljive, svejedno temperatura pri kojoj smo starili materijal nije dovoljna za neke značajnije promjene.

Abstract (english)

The high demand for plastic products in the last several decades resulted in significant environmental contamination with plastics. Through various aging processes, and mechanical degradation, plastics breaks down into ever smaller particles (< 5 mm) and forms microplastics, which are considered one of today's priority pollutants. Microplastics have negative effects on all components of the environment and can also have significant consequences on human health. In this study, polyethylene terephthalate (PET) and high-density polyethylene plastics were thermally aged at the melting temperatures of the polymers. Pristine and aged polymers were grind to microplastic size and then characterized by Fourier transform infrared spectroscopy (ATR-FTIR) and differential scanning calorimetry (DSC). For HDPE, no significant changes were observed between pristine and aged samples, indicating that the polymer was not aged at a sufficiently high temperature to initiate thermal degradation within the material. Aged PET samples showed visible colour changes as well as a decrease in certain values such as melting temperature (Tm), glass transition temperature (Tg), and crystallinity percentage (χ). Although some changes can be seen in the PET samples, the aging temperature of the material was not sufficient to cause major changes.

• Keywords: mikroplastika; okoliš; polimer; analiza; toplinsko starenje
• Keywords (english): microplastic; environment; polymer; analysis; thermal aging
• Language: croatian
• URN:NBN: urn:nbn:hr:149:128889
• Study programme: Title: Environmental Engineering - Undergraduate study; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka ekoinženjerstva (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka ekoinženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Embargoed access; Embargo expiration date: 2025-01-06
• Created on: 2023-11-28 13:39:23