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Title:Razgradnja polikarbonata (PC) v nadkritičnih ketonih : diplomsko delo univerzitetnega študijskega programa I. stopnje
Authors:ID Agrež, Anja (Author)
ID Škerget, Mojca (Mentor) More about this mentor... New window
ID Irgolič, Mihael (Comentor)
Files:.pdf UN_Agrez_Anja_2026.pdf (3,67 MB)
MD5: 874FBCBC6817ECBA641EE12B1B0C406C
 
Language:Slovenian
Work type:Bachelor thesis/paper
Typology:2.11 - Undergraduate Thesis
Organization:FKKT - Faculty of Chemistry and Chemical Engineering
Abstract:Polikarbonat (PC) je eden najpomembnejših tehničnih termoplastov, katerega vse večja uporaba povzroča tudi naraščajoče količine odpadnega materiala. Namen diplomskega dela je bil preučiti depolimerizacijo polikarbonata v nadkritičnih ketonih ter ovrednotiti vpliv temperature, reakcijskega časa, vrste topila in dodatka vode na dobit tekoče faze ter sestavo nastalih produktov. Eksperimenti so bili izvedeni v visokotlačnem šaržnem reaktorju z uporabo acetona, metil etil ketona (MEK), njunih mešanic z vodo in čiste vode. Nastale produkte smo analizirali z metodo plinske kromatografije z detektorjem plamenske ionizacije (GC-FID), trdne ostanke pa karakterizirali s Fourierjevo transformacijsko infrardečo spektroskopijo (FTIR). Rezultati so pokazali, da dodatek vode, temperatura in reakcijski čas pomembno vplivajo na dobit tekoče faze. Največji vpliv na učinkovitost procesa depolimerizacije je imel dodatek vode. Tako je bila že pri najnižji temperaturi (300 °C) in najkrajšem reakcijskem času (1 h) pri 50 % vodni raztopini acetona dobit tekoče faze 95,3 % in pri 50 % vodni raztopini MEK 96,6 %. To je več kot 11-krat več kot v čistem acetonu, kjer je bil pri teh pogojih 8,5 %, in čistem MEK, kjer je bil 7,6 %. Pri teh pogojih je bil dobit tekoče faze v čisti vodi in vodnih raztopinah večji kot v čistih ketonih pri najvišji temperaturi (350 °C) in istem reakcijskem času (1 h), kjer je bil pri acetonu 61,2 % in pri MEK 75,5 %. GC-FID analiza je potrdila prisotnost bisfenola A (BPA), fenola in 4-izopropenilfenola kot produktov razgradnje. Vpliv temperature, reakcijskega časa, vrste topila in dodatka vode na sestavo produktov razgradnje je podoben njihovemu vplivu na dobit tekoče faze. Glavni produkt razgradnje je bil BPA, njegov največji masni delež pa je bil določen za depolimerizacijo z 50 % vodnimi raztopinami ketonov (40,5 % za MEK:H2O in 38,1 % za aceton:H2O) pri temperaturi 300 °C in reakcijskem času 1 h in je bil kar za 3-5 krat višji kot pri reakcijah v čistih ketonih pri enakih pogojih. Rezultati potrjujejo, da so nadkritični ketoni, zlasti v kombinaciji z vodo, učinkoviti reakcijski mediji za kemijsko recikliranje polikarbonata in predstavljajo obetavno možnost za ponovno pridobivanje monomernih produktov z visoko dodano vrednostjo.
Keywords:polikarbonat, aceton, metil etil keton, nadkritični ketoni, dobit tekoče faze
Place of publishing:Maribor
Place of performance:Maribor
Publisher:[A. Agrež]
Year of publishing:2026
Number of pages:1 spletni vir (1 datoteka PDF (VIII, 36 str.))
PID:20.500.12556/DKUM-99481 New window
UDC:66.095.268:678.073(043.2)
COBISS.SI-ID:292479491 New window
Publication date in DKUM:16.09.2026
Views:87
Downloads:1
Metadata:XML DC-XML DC-RDF
Categories:KTFMB - FKKT
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Licences

License:CC BY-NC-ND 4.0, Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
Link:http://creativecommons.org/licenses/by-nc-nd/4.0/
Description:The most restrictive Creative Commons license. This only allows people to download and share the work for no commercial gain and for no other purposes.
Licensing start date:18.08.2026

Secondary language

Language:English
Title:Degradation of polycarbonate (PC) in supercritical ketones
Abstract:Polycarbonate (PC) is one of the most important engineering thermoplastics, and its increasing use is also leading to growing amounts of waste material. The purpose of this thesis was to study the depolymerization of polycarbonate in supercritical ketones and to evaluate the effect of temperature, reaction time, solvent type, and water addition on the liquid-phase yield and the composition of the resulting products. The experiments were conducted in a high-pressure batch reactor using acetone, methyl ethyl ketone (MEK), mixtures of these solvents with water, and pure water. The resulting products were analyzed by gas chromatography with a flame ionization detector (GC-FID), and the solid residues were characterized by Fourier transform infrared spectroscopy (FTIR). The results showed that the addition of water, temperature, and reaction time significantly influence the liquid-phase yield. The addition of water had the greatest effect on the efficiency of the depolymerization process. Thus, even at the lowest temperature (300 °C) and the shortest reaction time (1 h), the liquid-phase yield was 95.3 % in a 50 % aqueous acetone solution and 96.6 % in a 50 % aqueous MEK solution. This is more than 11 times higher than in pure acetone, where it was 8.5 % under these conditions, and in pure MEK, where it was 7.6 %. Under these conditions, the depolymerization rate in pure water and aqueous solutions was higher than in pure ketones at the highest temperature (350 °C) and the same reaction time (1 h), where it was 61.2% for acetone and 75.5% for MEK. GC-FID analysis confirmed the presence of bisphenol A (BPA), phenol, and 4-isopropenylphenol as degradation products. The effect of temperature, reaction time, solvent type, and water addition on the composition of the degradation products is similar to their effect on the depolymerization rate. The main degradation product was BPA, and its highest mass fraction was determined for depolymerization with 50% aqueous solutions of ketones (40.5% for MEK: H2O and 38.1% for acetone:H2O) at a temperature of 300 °C and a reaction time of 1 h, and was as much as 3 to 5 times higher than for reactions in pure ketones under the same conditions. The results confirm that supercritical ketones, particularly in combination with water, are effective reaction media for the chemical recycling of polycarbonate and represent a promising option for the recovery of high-value-added monomer products.
Keywords:polycarbonate, acetone, methyl ethyl ketone, supercritical ketones, liquid-phase yield


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