Utjecaj celuloznih i asocijativnih ugušćivača na reološka svojstva premaza

master's thesis

• Title (english): Influence of cellulose and associative thickeners on rheological properties of coatings
• Author: Andrea Perković
• Mentor: Mirela Leskovac (mentor)
• Committee member: Mirela Leskovac (predsjednik povjerenstva)
• Committee member: Krunoslav Žižek (član povjerenstva)
• Committee member: Lidija Furač (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2023-01-26, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract

Reologija se definira kao znanost koja proučava deformacije i tok tvari pod utjecajem vanjskih sila. Željeno ponašanje premaza tijekom obrade, skladištenja, nanošenja te nakon nanošenja od velike je važnosti u industriji premaza, a upravo se reologija koristi kao metoda za istraživanje ponašanja svojstava tečenja i deformacije tijekom navedenih faza. Ispitivanja u ovom radu provedena su na premazima na bazi vode. Za premaze na bazi vode postoje različite vrste ugušćivača koje se razlikuju prema načinu ugušćivanja premaza. Postoje ugušćivači koji ugušćuju samo vodenu fazu, a postoje i asocijativni ugušćivači koji viskoznost sustava povećavaju interakcijama s drugim komponentama premaza. Cilj ovog rada bio je ispitati utjecaj celuloznih i asocijativnih ugušćivača na reološka svojstva premaza. Korišteni celulozni ugušćivači su ugušćivači na bazi karboksimetil celuloze, hidroksietil celuloze, hidroksietil metil celuloze te hidrofobno modificirane hidroksietil celuloze. Navedeni ugušćivači viskoznost premaza povećavaju ugušćivanjem vodene faze, osim hidrofobno modificirane hidroksietil celuloze, kod koje je prisutan i asocijativni mehanizam ugušćivanja. Od asocijativnih ugušćivača korišteni su poliuretanski ugušćivači ili hidrofobno modificirani etoksilirani uretani (eng. hydrophobically modified ethoxylated urethanes - HEUR) te asocijativni akrilni ugušćivači poznati kao hidrofobno modificirane emulzije koje bubre u alkalijama (eng. hydrophobically modified alkali-swellable emulsions - HASE). U svrhu ispitivanja utjecaja dodanih ugušćivača na svojstva premaza, raznim metodama određivana su toplinska, reološka, fizikalna, primjenska i mehanička svojstva, kao i površinske karakteristike premaza, iz kojih se na kraju utvrdio utjecaj dodatka različitih ugušćivača na reološka svojstva premaza.

Abstract (english)

Rheology is defined as a science that studies the deformation and flow of matter under the influence of external forces. The desired behavior of the coating during processing, storage, application, and after application is of great importance in the coatings industry, and rheology is used as a method to study the flow behavior and deformations during the mentioned phases. The tests performed in this work were carried out on water-based coatings. There are different types of thickeners for water-based coatings, depending on the method used to thicken the coating. There are thickeners that only smother the water phase, and there are also associative thickeners that increase the viscosity of the system by interacting with other components of the coating. The aim of this work was to investigate the influence of cellulose and associative thickeners on the rheological properties of the coating. The cellulose thickeners used are thickeners based on carboxymethylcellulose, hydroxyethylcellulose, hydroxyethylmethylcellulose and hydrophobically modified hydroxyethylcellulose. The above thickeners increase the viscosity of the coating by thickening the aqueous phase, with the exception of hydrophobically modified hydroxyethyl cellulose, which also has an associative thickening mechanism. Polyurethane thickeners or hydrophobically modified ethoxylated urethanes (HEUR) and associative acrylic thickeners known as hydrophobically modified alkali swellable emulsions (HASE) were used as associative thickeners. In order to test the influence of the added thickeners on the properties of the coating, various methods were used to determine the thermal, rheological, physical, application, mechanical and surface properties of the coating, from which the influence of the addition of different thickeners on the rheological properties of the coating was determined.

• Keywords: reologija; reološka svojstva; celulozni ugušćivači; asocijativni ugušćivači
• Keywords (english): rheology; rheological properties; cellulose thickeners; associative thickeners
• Language: croatian
• URN:NBN: urn:nbn:hr:149:790959
• 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: Closed access
• Created on: 2023-02-15 14:13:33