Vpliv ogljikovih nanocevk na mehanske lastnosti polietilena

Plesničar, Tadej (author), Slemenik Perše, Lidija (mentor)

Ogljikove nanocevke predstavljajo superiorna multifunkcijska nanopolnila v polimernih nanokompozitih, saj omogočajo odlično mehansko ojačitev, električno prevodnost in druge podobne lastnosti. Z uporabo nanoindentorja smo v sklopu diplomskega dela obravnavali vpliv koncentracije eno-stenskih ogljikovih nanocevk na mehansko ojačitev polimernih nanokompozitov iz polietilena nizke in polietilena visoke gostote. Rezultati so pokazali, da geometrijski preplet nanocevk znotraj polimernega veziva vpliva na dodatno mehansko ojačitev, vendar le od kritičnega masnega deleža nanopolnila (0,7 mas.% nanocevk). Največjo izboljšavo smo ugotovili pri približno 4 mas.% nanopolnila, kjer se modul elastičnosti v primerjavi z osnovnim materialom (brez dodanega nanopolnila) poveča za 274 % in trdota za 246 % polietilenu z nizko gostoto. Polietilenu z visoko gostoto se modul elastičnosti v primerjavi z osnovnim materialom (brez dodanega nanopolnila) poveča za 70 % in trdota za 73 %. Pri 5 mas.% dodanega nanopolnila se pojavi aglomeracija, kar je razvidno iz upada mehanskih lastnosti. Koncentracija nanopolnila na hrapavost površine nima bistvenega vpliva. S preizkusom praske smo pridobili hrapavost površine, največjo obremenitev, globino obremenitve in prečni presek. Iz dobljenih rezultatov sta vidni globina in širina praske ter višina nakopičenega materiala ob praski.

• Language: Slovenian
• Keywords: polimeri, nanokompoziti, nanopolnila, ogljikove nanocevke, mehanske lastnosti
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: FS - Faculty of Mechanical Engineering
• Place of publishing: Ljubljana
• Publisher: [T. Plesničar]
• Year: 2023
• Number of pages: XXII, 41 str.
• PID: 20.500.12556/RUL-143787
• UDC: 620.3:620.17:546.262.5(043.2)
• COBISS.SI-ID: 140797443
• Publication date in RUL: 12.01.2023

PLESNIČAR, Tadej, 2023, Vpliv ogljikovih nanocevk na mehanske lastnosti polietilena [online]. Bachelor’s thesis. Ljubljana : T. Plesničar. [Accessed 6 April 2025]. Retrieved from: https://repozitorij.uni-lj.si/IzpisGradiva.php?lang=eng&id=143787

Secondary language

• Language: English
• Title: Influence of carbon nanotubes on mechanical properties of polyethylene

Abstract

Carbon nanotubes represent superior multifunctional nanofillers in polymer nanocomposites, as they enable excellent mechanical reinforcement, electrical conductivity and other similar properties. Using a nanoindenter, we studied the influence of the concentration of single-walled carbon nanotubes on mechanical strengthening of polymer nanocomposites made of low-density polyethylene and high-density polyethylene. The results showed that the geometric entanglement of carbon nanotubes leads to the additional mechanical reinforcement when the critical mass fraction of the nanofiller (0,7 % mass.) is exceeded. The best improvement was found at about 4 %wt. of nanofiller, where the modulus of elasticity, compared to the same material without any nanofillers increases by 274 % and the hardness by 246 % for low-density polyethylene. For high-density-polyethylene the modulus of elasticity, compared to the same material without any nanofillers increases by 70 % and the hardness by 73 %. At 5 %wt. of the added nanofiller, the agglomeration occurs, which is evident from the decrease of mechanical properties. The concentration of the nanofiller has no significant effect on the surface roughness. With the scratch test we obtained the surface roughness, the maximum load, the depth of the load, the cross-section.

• Keywords: polymers, nanocomposites, nanofillers, carbon nanotubes, mechanical properties