Struktura i svojstva polimernih prevlaka sa šelakom

master's thesis

• Title (english): Structure and properties of polymer coatings with schellac
• Author: Petra Džono
• Mentor: Mirela Leskovac (mentor)
• Committee member: Mirela Leskovac (predsjednik povjerenstva)
• Committee member: Emi Govorčin Bajsić (član povjerenstva)
• Committee member: Krunoslav Žižek (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2021-09-30, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract

Danas se uglavnom koriste sintetski polimerni materijali dobiveni iz nafte. Masovno iskorištavanje nafnih sirovina uzrokuje globalne klimatske promjene i osim toga, njihove raspoložive količine su ograničene, a dobiveni sintetski polimerni materijali nerazgradivi zbog čega dolazi do gomilanja ambalažne „plastike“ u okolišu. Iz tih je razloga tema brojnih znanstvenih radova razvoj biorazgradivih i ekološki prihvatljivih biopolimera. U ovome radu istražena su svojstva prevlaka mješavina šelaka (SCH) i polivinilpirolidona (PVP) pripremljenih iz otopine etanola, uz dodatak glicerina (G) te polietilenglikola 4 000 i 12 000 (PEG4, PEG12) različitih molekulskih masa. Na prevlakama mješavina SCH/PVP/G, SCH/PVP/PEG4 i SCH/PVP/PEG12 provedena su ispitivanja toplinskih svojstava primjenom diferencijalne pretražne kalorimetrije, termogravimetrijske analize i određivanjem toplinske vodljivosti, te ispitivanja površinskih karakteristika primjenom tehnike kontaktnog kuta. Morfologija i mehanizam popuštanja praćeni su primjenom pretražne elektronske mikroskopije, a barijerna svojstva prevlaka određena su mjerenjem propusnosti vodene pare. Utvrđena je znatna ovisnost sastava polimernih mješavina i dodatka plastifikatora glicerola, PEG4 i PEG12 polimera. PEG4 i PEG12 polimeri su pokazali kompatibilizacijski učinak kod mješavina s manjim udjelom PVP polimera.

Abstract (english)

Today, synthetic polymers derived from petroleum are mainly used. The mass exploitation of petroleum raw materials causes global climate change. Moreover, they are available only in limited quantities and are also non-degradable, leading to the accumulation of packaging plastic in the environment. For these reasons, the development of biodegradable and environmentally friendly biopolymers is the subject of numerous scientific works. In this work, the properties of coatings made from blends of shellac and polyvinylpyrrolidone (PVP) with different molecular weights prepared from an ethanol solution with the addition of glycerol (G) and polyethylene glycol 4 000 and 12 000 (PEG4, PEG12) were studied. The coating samples of the blends SCH / PVP / G, SCH / PVP / PEG4 and SCH / PVP / PEG12 were investigated for their thermal properties by differential scanning calorimetry, thermogravimetric analysis and thermal conductivity measurements and for their surface properties by contact angle technique. The morphology and relaxation mechanism were monitored by scanning electron microscopy and the barrier properties of the coatings were determined by measuring the water vapor permeability. Significant dependence was found on the composition of the polymer blends and the addition of glycerol plasticizers, PEG4 and PEG12 polymers. PEG4 and PEG12 polymers showed a compatibilizing effect in blends with a lower proportion of PVP polymers.

• Keywords: šelak; polivinilpirolidon; glicerin; PEG 4 000; PEG 12 000; toplinska svojstva; parametri adhezije; barijerna svojstva; morfologija
• Keywords (english): shellac; polyvinylpyrrolidone; glycerin; PEG 4 000; PEG 12 000; thermal properties; adhesion parameters; barrier properties; morphological analysis
• Language: croatian
• URN:NBN: urn:nbn:hr:149:570256
• Study programme: Title: Chemical Engineering - Graduate study; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka kemijskog inženjerstva (magistar/magistra inženjer/inženjerka kemijskog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2023-04-21 12:28:49