Priprava i karakterizacija materijala na osnovi celuloze i N-vinil-2-pirolidona

undergraduate thesis

• Title (english): Preparation and characterization of materials from cellulose and N-vinyl-2-pyrrolidone
• Author: Dora Kordić
• Mentor: Elvira Vidović (mentor)
• Committee member: Elvira Vidović (predsjednik povjerenstva)
• Committee member: Zlata Hrnjak-Murgić (član povjerenstva)
• Committee member: Domagoj Vrsaljko (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2021-09-17, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract

Celuloza je najrasprostranjeniji prirodni polimer. Sve se više istražuje radi korištenja u medicinske i industrijske svrhe, prije svega zbog svoje biorazgradivosti, biokompatibilnosti, široke dostupnosti i neškodljivosti. Cilj ovog rada sintetizirati je hidrogelove celuloze graftirane sa N-vinil-2-pirolidonom i umrežene sa N,N-metilen-bis-amidom (MBA) na dva načina; izravnom sintezom i zračenjem, te usporediti njihova svojstva. Kemijska reakcija celuloze i N-vinil-2-pirolidona (omjer 1:1, 1:3 i 1:5 mol/mol) provedena je u sustavu otapala N,N-dimetilacetamid/LiCl s peroksidnim inicijatorom pri 90°C uz N,N-metilen-bis-akrilamid kao umreživač. Mikrostruktura pripravljenih hidrogelova ispitana je pretražnom elektronskom mikroskopijom. Sintetizirani hidrogelovi karakterizirani su FTIR spektroskopijom. Hidrogelovima je određivan stupanj bubrenja u deioniziranoj vodi, a odabrani sustavi su ispitani u kiselini i lužini. Temeljem omjera intenziteta karakterističnih vrpci pri
1645-1660 cm^-1 i 897 cm^-1 utvrđeno je značajno povećanje nakon zračenja sa 10 kGy naspram hidrogela priređenog kemijskom sintezom. S povećavanjem doze zračenja na
30 kGy smanjuju se omjeri intenziteta u hidrogelovima obje serije uzoraka, a dodatnim zračenjem na 100 kGy ne dolazi do značajne promjene intenziteta. Provedbom pokusa bubrenja u periodu od 2 mjeseca najveći stupanj bubrenja zabilježen je kod serije uzoraka 1:3-100 kGy. Pretražnom elektronskom mikroskopijom utvrđeno je da ozračivanje značajno doprinosi povećanju poroznosti pripravljenog hidrogela kao i da nakon osmotjednog bubrenja sfere pokazuju značajnu deformaciju oblika.

Abstract (english)

Cellulose is the most common natural polymer. It has been intensively researched for medical and industrial purposes due to its biodegradability, biocompatibility, availability and harmlessness. The focus of this research paper it the synthesis of cellulose hydrogels grafted with N-vinyl-2pyrrolidone and crosslinked with N,N-methylenebisacrilamide (MBA) in two different ways, namely by direct synthesis and synthesis by radiation, as well as the comparison of their properties. The chemical reaction of cellulose and N-vinyl-2-pyrrolidone was carried out in the solvent N,N-dimethyl acetamide/LiCl with a peroxide initiator at the temperature of 90°C and using N,N-methylene-bis-acrylamide as a crosslinker. Microstructure of prepared hydrogels were examined by scanning electron microscopy. The synthesised hydrogels are characterized by FTIR spectroscopy. The degree of swelling was controlled in unionized water, as well as in an acidic- and an alkaline solution for some systems. Based on the ratio of intensity of a band at 1645-1660 cm^-1 and 897 cm^-1, it has been concluded drastically increase after irradiation of 10 kGy compared to the hydrogel prepared by chemical synthesis. Furthermore, the ratio of intensity in hydrogels in both series lowers by increasing the radiation to 30 kGy. Finally, with an excess radiation of
100 kGy, there is no change in the intensity. During the period of two months during which the experiment was being conducted, the greatest level of swelling occurred in the series 1:3-100 kGy. By using scanning electron microscopy, it has been determined that 1.) radiation significantly increases porosity of prefabricated hydrogel and 2.) after eight weeks of swelling, the sphere shows a significant shape deformation.

• Keywords: bubrenje; degradacija; SEM
• Keywords (english): swelling; degradation; SEM
• Language: croatian
• URN:NBN: urn:nbn:hr:149:579966
• 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: 2023-04-05 12:35:45