Priprema i karakterizacija kompozita polietilena s različitim česticama hematita

master's thesis

• Title (english): Preparation and characterization of polyethylene composites with different hematite particles
• Author: Elza Štefanović
• Mentor: Ljerka Kratofil Krehula (mentor)
• Committee member: Ljerka Kratofil Krehula (predsjednik povjerenstva)
• Committee member: Emi Govorčin Bajsić (član povjerenstva)
• Committee member: Marija Vuković Domanovac (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2021-09-16, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract

Kompoziti polietilena i željezovih oksida slabije su istraživani u odnosu na druge kompozite polietilena, ali se njihovom kombinacijom mogu dobiti aktivni kompozitni materijali sa širokim područjem primjene. Takvi materijali sadrže aktivne tvari koje imaju različita funkcijska svojstva u cilju poboljšanja pojedinih svojstava polimera, a time i produljivanja njegovog životnog vijeka. U ovom su radu pripremljeni kompoziti polietilena niske gustoće (LDPE) s česticama hematita različitih veličina (hematit većih dimenzija označen je kao HC1, a onaj manjih dimenzija kao HS2). Udio hematita u uzorcima bio je 0.25, 0.5 i 1 %. Kompoziti LDPE/HC1 i LDPE/HS2 pripremljeni su umješavanjem u Brabender gnjetilici nakon čega su na hidrauličkoj preši isprešani u folije i pločice. Dobiveni uzorci kompozita karakterizirani su FTIR spektroskopijom, termogravimetrijskom analizom i diferencijalnom pretražnom kalorimetrijom. Dobiveni rezultati pokazuju da se toplinska stabilnost LDPE-a povećala dodatkom punila hematita što znači da su navedeni kompoziti toplinski stabilniji. Naročito se stabilnost materijala povećala dodatkom čestica hematita HS2 koje su manjih dimenzija. Dodatkom punila hematita u matricu LDPE-a dolazi do neznatnog smanjenja kristališta te porasta stupnja kristalnosti. Porast stupnja kristalnosti može se pripisati tome da hematit djeluje kao nukleacijsko sredstvo.

Abstract (english)

Polyethylene and iron oxide composites have been less investigated than other polyethylene composites, but their combination can yield active composite materials with a wide range of applications. Such materials contain active substances that have different functional properties in order to improve the individual properties of polymer, and thus prolong its shelf life. In this paper, low density polyethylene (LDPE) composites with hematite particles of different sizes were prepared (hematite of larger dimensions is designated as HC1, and that of smaller dimensions as HS2). The content of hematite in the samples was 0.25, 0.5 and 1 %. LDPE/HC1 and LDPE/HS2 composites are prepared by mixing in a Brabender kneader and then pressed into foils and plates on a hydraulic press. The obtained composite samples are characterized by FTIR spectroscopy, thermogravimetric analysis and differential scanning calorimetry. The obtained results show that the thermal stability of LDPE was increased by the addition of hematite filler, which means that these composites are more thermally stable. In particular, the stability of the material was increased by the addition of smaller hematite HS2 particles. The addition of hematite filler to the LDPE matrix slightly reduces the crystallinity and increases the degree of crystallinity. The increase in the degree of crystallinity can be attributed to the fact that hematite acts as a nucleating agent.

• Keywords: polietilen niske gustoće; hematit; polimerni kompoziti; toplinska stabilnost
• Keywords (english): low density polyethylene; hematite; polymer composites; thermal stability
• Language: croatian
• URN:NBN: urn:nbn:hr:149:714063
• Study programme: Title: Materials Science and 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: 2023-04-13 13:08:40