Utjecaj titanijevog dioksida na svojstva poliakrilatnih filmova

master's thesis

• Title (english): Influence of titanium dioxide on the properties of polyacrylate films
• Author: Ruth Eva Jensch
• Mentor: Sanja Lučić Blagojević (mentor)
• Committee member: Sanja Lučić Blagojević (predsjednik povjerenstva)
• Committee member: Zrinka Buhin Šturlić (član povjerenstva)
• Committee member: Domagoj Vrsaljko (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2021-02-26, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract

Poliakrilati (PAK) kao produkti emulzijske polimerizacije imaju široku primjenu u proizvodnji boja, premaza, adheziva i sl. Poliakrilat koji je ispitivan u ovom radu je kopolimer metil-metakrilata i butilakrilata i koristi se kao zaštitni premaz za drvo. U svrhu očuvanja od UV zračenja premazu se dodaju nanočestice titanijevog dioksida koje mogu apsorbirati UV zračenje i time usporiti površinsku razgradnju drva. Sustavi PAK/TiO2 pripremljeni su emulzijskom polimerizacijom na dva različita načina: in situ i ex situ. Pripravljeni su sustavi PAK/TiO2 emulzija s 1%, 2%, 3% i 4% TiO2 u odnosu na masu monomera. Kako bi se ispitao utjecaj koncentracije titanijevog dioksida i načina priprave na svojstva poliakrilatnih filmova provedena je karakterizacija filmova dobivenih iz emulzija koja uključuje: infracrvenu spektroskopiju s Fourierovom transformacijom signala, ispitivanje morfologije, UV – VIS spektroskopije, promjenu boje, ispitivanje toplinskih svojstava diferencijalnom pretražnom kalorimetrijom (DSC) te ispitivanje toplinske stabilnosti termogravimetrijskom analizom (TGA). Rezultati su pokazali da način priprave emulzija nema utjecaj na raspodjelu punila, ali znatno utječe na dispergiranost odnosno stupanj aglomeracije punila. Uzorci dobiveni ex situ postupkom imaju lošiju dispergiranost i veće aglomerate. Uzorci filmova dobiveni in situ postupkom bolje apsorbiraju UV zračenje u odnosu na filmove dobivene ex situ postupkom i time bolje štite poliakrilatnu matricu od UV razgradnje. Vidjivi dio zračenja bolje propuštaju ex situ filmovi te imaju veću transparentnost. Promjena boje izraženija je kod in situ filmova te se povećava s porastom koncentracije TiO2. DSC tehnikom je utvrđeno da povećanje koncentracije TiO2 kod oba načina priprave dovodi do porasta temperature staklišta poliakrilata te da je ono izraženije u ex situ filmovima. Iz rezultata TGA utvrđuje se da dodatak TiO2 neovisno o načinu priprave povećava toplinsku stabilnost poliakrilatne matrice u ranim i kasnijim fazama razgradnje.

Abstract (english)

Acrylic based polymers (PAKs) have wide application in the production of paints, coatings, adhesives etc. The polyacrylate investigated in this paper is a copolymer of methyl methacrylate and butyl acrylate and is used as a protective coating for wood. For protection against UV radiation, titanium dioxide nanoparticles, which can absorb UV radiation and thus slow the surface degradation of wood caused by exposure to UV rays, are added to the coating. PAK/TiO2 are prepared by emulsion polymerization in two different ways: in situ and ex situ. PAK /TiO2 emulsions with 1%, 2%, 3% and 4% TiO2 by weight of monomers were prepared. To examine the influence of titanium dioxide concentration and the method of preparation on the properties of polyacrylate emulsions, a characterization of films prepared from the emulsions was performed, including Fourier-transform infrared spectroscopy, morphology examination, UV - VIS spectroscopy, color change, thermal properties by differential scanning calorimetry (DSC) and thermal stability by thermogravimetric analysis (TGA). The results showed that the method of preparation does not have a significant effect on the distribution of fillers, but it significantly affects the degree of agglomeration. Samples obtained by the in situ process better absorb UV radiation compared to the systems obtained by the ex situ process and thus better protect the polyacrylate matrix from UV degradation. The visible part of radiation is better transmitted in ex situ films, which have greater transparency. The color change is more pronounced in films obtained by the in situ process and it increases with the increase of TiO2 concentration. The DSC analysis has shown that the increase of TiO2 concentration increases the glass transition temperature of polyacrylates and that the glass transition tempreture increase is more pronounced in ex situ films. The results of the TGA indicate that the addition of TiO2 regardless of the preparation method increases the thermal stability in the polyacrylate matrix in the beginning and later phases of degradation.

• Keywords: poliakrilati; TiO2; in situ emulzijska polimerizacija; ex situ; FTIR; TGA; DSC; promjena boje; morfologija; UV – VIS spektroskopija
• Keywords (english): polyacrylates; TiO2; in situ emulsion polymerization; ex situ; FTIR; TGA; DSC; color change; morphology; UV – VIS spectroscopy
• Language: croatian
• URN:NBN: urn:nbn:hr:149:438788
• 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: Open access
• Created on: 2023-04-05 13:04:57