Učinak nanopunila na toplinsku stabilnost polimera

undergraduate thesis

• Title (english): Influence of nanofiller on thermal stability of polymers
• Author: Lucija Krmek
• Mentor: Sanja Lučić Blagojević (mentor)
• Committee member: Sanja Lučić Blagojević (predsjednik povjerenstva)
• Committee member: Zrinka Buhin Šturlić (član povjerenstva)
• Committee member: Vesna Ocelić Bulatović (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2017-09-08, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Basic Technical Sciences; Materials

Abstract

Cilj ovog rada bio je upoznati se s najvažnijim vrstama nanopunila i njihovim učincima na toplinsku stabilnost polimera, koji su prikazani istraživanjima brojnih znanstvenika, temeljenih na termogravimetrijskim rezultatima i analizama. Polimerni nanokompoziti pokazuju znatno bolja svojstva u usporedbi s čistim polimerom ili klasičnim kompozitom zahvaljujući dispergiranosti punila na nanorazini. Dosadašnja istraživanja pokazala su da dodatak nanopunila ima uglavnom pozitivan učinak na toplinsku stabilnost, ali može imati i negativan ili neznatan što ovisi o brojnim faktorima kao što su količina i način modifikacije nanopunila te atmosfera i temperaturno područje u kojoj se prati razgradnja. Razlozi pozitivnog učinka nanopunila na toplinska svojstva polimera mogu biti: (i) ograničeno toplinsko gibanje polimernih lanaca između slojeva punila, (ii) prisutnost nanopunila kao prepreka za smanjenje propusnosti hlapljivih razgradnih produkata iz materijala te (iii) znatno veći udio matrice u međufaznom sloju, što dovodi do poboljšanja dispergiranosti punila i jačine interakcija na međufazi polimer/nanopunilo. Ponekad može doći do dvostrukog djelovanja nanopunila koje prvo djeluje kao toplinski izolator i barijera za prijenos hlapljivih produkata nastalih tijekom razgradnje, no s druge strane, centri katalitičkog djelovanja glinenih slojeva ubrzavaju razgradnju polimera što na kraju uzrokuje neznatan ili negativan učinak dodatka nanopunila. Preostale nečistoće, dodatne komponente ili preostali sadržaj dodanog katalizatora za sintezu nanopunila također mogu uzrokovati negativan učinak na toplinsku stabilnost nanokompozita. Na temelju dosadašnjih istraživanja, dodatak slojevitih punila u odnosu na ostale vrste nanopunila, najviše doprinosi toplinskoj stabilnosti polimera.

Abstract (english)

The main objective of this study was to get acquainted with the most important types of nanofillers and their affects on the thermal stability of the polymers, shown in the researches of numerous scientists, based on thermogravimetric results and analysis. Polymer nanocomposites exhibit significantly better properties compared to pure polymer or classical composites thanks to dispersion of nanoparticles fillers. Previous studies have shown that the addition of nanofillers have a mostly positive effect on thermal stability, but may be negative or minor depending on numerous factors such as the amount and way of modification of nanofillers or the atmosphere and temperature range in which the degradation is monitored. The reasons for the positive effect of nanofillers on the thermal properties of the polymer may be: (i) limited thermal movement of polymer chains between the filler layers, (ii) presence of the nanofiller as a barrier to reduce the permeability of volatile degradation products from the material and (iii) a significantly greater part of the matrix in the interphase, thereby leading to improved filler dispersion and strength of interaction at interface polymer/nanofiller. Sometimes there might be a double action of the nanofiller which first acts as a thermal insulator and a barrier to the transfer of volatile products formed during decomposition, but on the other hand, the catalytic action of the clay layers accelerates the degradation of the polymer which ultimately causes a slight or negative effect of nanofiller addition. Remaining impurities, additional components or residual contents of catalyst for the synthesis of nanofiller can also cause a negative effect on the thermal stability of the nanocomposites. Based on the previous studies, the addition of layered nanofillers in comparison to other types of nanofillers contributes mostly to the thermal stability of the polymer.

• Keywords: polimerni nanokompoziti; toplinska stabilnost
• Keywords (english): polymer nanocomposites; thermal stability
• Language: croatian
• URN:NBN: urn:nbn:hr:149:660699
• 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: 2021-01-08 13:34:00