Struktura i svojstva kompozita s prirodnim vlaknima

undergraduate thesis

• Title (english): Structure and properties of natural fiber composites
• Author: Tea Lončarić Klobuk
• Mentor: Mirela Leskovac (mentor)
• Mentor: Zrinka Buhin Šturlić (komentor)
• Committee member: Mirela Leskovac (predsjednik povjerenstva)
• Committee member: Zrinka Buhin Šturlić (član povjerenstva)
• Committee member: Iva Movre Šapić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2020-09-24, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract

Kompozit je mješavina dva ili više različitih elemenata ili faza. Faza koja je kontinuirana naziva se matrica, a druga faza je određena kao učvršćujuća faza, odnosno ojačavalo (punilo) koje poboljšava mehanička svojstva matrice. U ovom radu istraživana su svojstva čistih polimera te polimernih kompozita ojačanih prirodnim punilom – jutenim vlaknom. Korišteni polimeri bili su polipropilen (PP), polietilen niske gustoće (PE-LD), polikaprolakton (PCL) i polistiren visoke udarne žilavosti (HIPS). Kompoziti s 3 % masenog udjela punila pripravljeni su umješavanjem u Brebender gnjetilici i prešanjem na hidrauličkoj preši. Određivana su toplinska (diferencijalnom pretražnom kalorimetrijom, DSC i termogravimetrijskom,
TG analizom) i mehanička svojstva. Rezultati dobiveni DSC analizom su pokazali da dodatak jutenog vlakna potiče nukleaciju kod PE-LD matrice, te povećava entalpiju kristalizacije
PE-LD, PP i PCL-a. Dodatak vlakna nema nikakvog utjecaja na staklište HIPS-a. Prema vrijednostima TGA analize dodatak jutenog vlakana povećao je toplinsku stabilnost PE-LD, a smanjio kod PP i PCL-a. HIPS dodatkom punila počinje proces razgradnje prije, dok punilo u kasnijim stupnjevima razgradnje pomiče temperature razgradnje na više (za nekoliko stupnjeva). Mehanička svojstva kompozita različita su u odnosu na matricu. Juteno vlakno kod svih polimera povećava prekidnu čvrstoću i modul.

Abstract (english)

A composite is a mixture of two or more different elements or phases. A phase that is continuous is called a matrix and the second phase is defined as a fixing phase, or a reinforcer (filler) that improves the mechanical properties of the matrix. This work investigates properties of pure polymer and polymer composites reinforced with natural filler-jute fiber. Polypropylene (PP), low density polyethylene (LDPE), polycaprolactone (PCL) and high impact polystyrene (HIPS) were used. The composite with 3 weight % of the filler were prepared by mixing in a Brabender mixer and pressing on a hydraulic press. Thermal (differential scanning calorimetry, DSC and thermogravimetric, TG analysis) and mechanical properties of pure polymers and obtained composites were determined and compared. The results obtained by DSC analysis showed that the addition of jute fiber promotes nucleation of PE-LD matrix and increase crystallization enthalpy of PE-LD, PP and PCL. The addition of jute fiber has no effect on the glass transiton temperature of HIPS. According to the values of TGA analysis, the addition of jute fiber increased the thermal stability of PE-LD, and decreased it in PP and PCL. HIPS addition of filler starts the decomposition process earlier, while the filler in the later stages of decomposition increased degradation temperatures. Mechanical properties of composites are different in relation to the polymer matrix. Modul and strength at break are increased with juta fiber addition.

• Keywords: kompozit; polimer; juteno vlakno; mehanička svojstva; toplinska svojstva; DSC; TGA
• Keywords (english): composite; polymer; jute fiber; mechanical properties; thermal properties; DSC; TGA
• Language: croatian
• URN:NBN: urn:nbn:hr:149:175318
• 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: Access restricted to students and staff of home institution
• Created on: 2023-05-05 08:52:52