Vpliv dodatka tekočekristalnega polimera na kompozitni sistem SrFe12O19 s polifenilen sulfidom : diplomsko delo

Uršič, Ana (author), Bizjak, Milan (mentor), Kosmač, Karla (comentor)

Trajni magneti, ki se jih izdeluje s postopkom sintranja, so trdi in krhki. Ravno zaradi teh lastnosti niso primerni za uporabo na vseh področjih. V aplikacijah, kjer taki magneti ne pridejo v poštev, je smiselna uporaba plastomagnetov. Gre za materiale, izdelane iz magnetnih prahov, katerih delce povezuje določeno vezivo, na primer razne smole, gume ali polimeri. V sklopu diplomskega dela smo izdelali plastomagnetni material na osnovi magnetnega prahu stroncijevega heksaferita (SrFe12O19) z vezivom polifenilen sulfida (PPS), ki smo mu dodali tekočekristalni polimer (LCP). Zanimal nas je vpliv slednjega na gostoto in magnetne ter mehanske lastnosti. Izdelali smo predmešanico magnetnega prahu z dodanima aditivoma in polimerno predmešanico obeh uporabljenih polimerov. Pripravljeni predmešanici smo s tehnologijo ekstrudiranja oblikovali v granulat, ki smo ga nato posušili. Z injekcijskim brizganjem smo posušen granulat preoblikovali v vzorce, na katerih smo izvajali preiskovalne metode. Magnetnim valjastim vzorcem smo najprej izmerili gostoto ter s pomočjo magnetenja in razmagnetenja določili glavne magnetne lastnosti materiala. Na preizkušancih v obliki epruvet smo izvedli tritočkovni upogibni preizkus za določanje upogibnih karakteristik ter natezni preizkus za določanje trdnostnih in preoblikovalnih lastnosti. Rezultate meritev izdelanega materiala smo primerjali z enakim materialom brez dodanega tekočekristalnega polimera.

• Language: Slovenian
• Keywords: SrFe12O19, PPS, LCP, ekstruzija, injekcijsko brizganje
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: NTF - Faculty of Natural Sciences and Engineering
• Place of publishing: Ljubljana
• Publisher: [A. Uršič]
• Year: 2021
• Number of pages: XII, 43 f.
• PID: 20.500.12556/RUL-127967
• UDC: 669
• COBISS.SI-ID: 71561475
• Publication date in RUL: 30.06.2021

URŠIČ, Ana, 2021, Vpliv dodatka tekočekristalnega polimera na kompozitni sistem SrFe12O19 s polifenilen sulfidom : diplomsko delo [online]. Bachelor’s thesis. Ljubljana : A. Uršič. [Accessed 16 April 2025]. Retrieved from: https://repozitorij.uni-lj.si/IzpisGradiva.php?lang=eng&id=127967

Secondary language

• Language: English
• Title: Influence of Liquid Crystalline Polymer Addition to SrFe12O19 Composite System With Polyphenylene Sulphide : diploma work

Abstract

Permanent magnets made by the sintering process are hard and brittle. For this very reason, they are not suitable for all applications. In applications where the use of such magnets is not possible, we can use bonded magnets. They consist of magnetic powders whose particles are bound by a special binder, such as various resins, rubbers or polymers. As part of the diploma work, we prepared a plastic magnetic material based on the magnetic powder of strontium hexaferrite (SrFe12O19) with a polyphenylene sulphide (PPS) as a binder, to which we added a liquid crystalline polymer (LCP). We were interested to see the effect of the latter on the density, magnetic and mechanical properties. We prepared a premix of magnetic powder with additives and a polymer premix of both polymers. The prepared premixes were converted into composite granules using extrusion technology, which were later dried. Injection molding was used to convert the dried granules into samples that were used as part of a research method. First, the density was measured using magnetic cylindrical samples and the main magnetic properties of the material were determined using magnetization and demagnetization. A three-point bending test was performed on the test specimens in the form of test tubes to determine the bending properties, followed by a tensile test, used to determine the strength and forming properties. The measurement results of the prepared material were compared with the same material without the addition of liquid crystalline polymer.

• Keywords: SrFe12O19, PPS, LCP, extrusion, injection molding