Utjecaj UV zračenja na strukturu polimera

undergraduate thesis

• Title (english): Influence of UV irradiation on polymer structure
• Author: Lorena Bartulović
• Mentor: Zlata Hrnjak-Murgić (mentor)
• Committee member: Zlata Hrnjak-Murgić (predsjednik povjerenstva)
• Committee member: Emi Govorčin Bajsić (član povjerenstva)
• Committee member: Marijana Kraljić Roković (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2023-09-21, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract

Pod utjecajem atmosferskih uvjeta, ultraljubičastog zračenja (eng. ultraviolet – UV) i topline, polimerni materijali degradiraju pri čemu dolazi do promjene njihovih svojstava kao što je na primjer povećanje krtosti i lomljivosti što za posljedicu daje nastajanje mikroplastike u okolišu. U svrhu izrade ovog rada korišteni su materijali polietilen visoke gustoće (HDPE) i polipropilen (PP) koji su izloženi atmosferskom starenju. Uzorci HDPE folija i PP folija su izloženi procesu starenja u razdoblju od 14, 28, 42 i 530 dana. Nakon tog vremenskog razdoblja, promjene koje su se dogodile uslijed procesa degradacije praćene su pomoću infracrvene spektroskopije s Fourierovom transformacijom (eng. Fourier-transform infrared spectroscopy, FTIR). Pomoću FTIR spektara identificirana je pojava razradnih skupina (karboksilne, karbonilne te oksi skupine) koje su nastale kao posljedica razgradnje polimera. Intenzitet razgradnje okarakteriziran je za određivanje karbonilnog indeksa (C.I.).
Rezultati dobiveni primjenom metode infracrvene spektroskopije pokazuju da povećanjem vremena starenja dolazi do promjene strukture molekula polimera, što je vidljivo iz povećanja karbonilnog indeksa.

Abstract (english)

Under the influence of atmospheric conditions, ultraviolet (UV) radiation and heat, polymer materials undergo degradation, leading to changes in their properties such as increased brittleness and fragility, resulting in accumulation of microplastic in the environment. In this study, high-density polyethylene (HDPE) and polypropylene (PP) materials were used and were exposed to atmospheric aging. Samples of HDPE film and PP film were subjected to aging for periods of 14, 28, 42 and 530 days. After this period of time, the changes that occurred due to degradation processes were monitored using Fourier-transform infrared spectroscopy (FTIR). The FTIR spectra were utilized to identify the presence of newly formed groups (carboxyl, carbonyl and oxy groups) as a result of polymer degradation. The degree of degradation was determinated by carbonyl index (C.I.). The results of FTIR spectroscopy show that with increasing aging time, changes in the molecular structure of the polymer can be observed, which are reflected in an increased carbonyl index.

• Keywords: polipropilen; polietilen visoke gustoće; UV zračenje; razgradnja; mikroplastika
• Keywords (english): polypropylene; high-density polyethylene; UV radiation; degradation; microplastics
• Language: croatian
• URN:NBN: urn:nbn:hr:149:043611
• 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: HRZZ; Funding stream: IP
• Study programme: Title: Materials Science and Engineering - Undergraduate study; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka kemijskog inženjerstva (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka kemijskog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2023-11-29 17:00:31