Surface modification of copper-based flakes for conductive polymer composites

Mohor Mihelčič (Author), Alen Oseli (Author), Tadej Rojac (Author), Lidija Slemenik Perše (Author)

Abstract

The physical properties as well as thermal and electrical stability of copper particles can be improved by surface protection, which mainly depends on the coating material. Our study was, therefore, focused on the rheological, thermal, mechanical and electrical characterization of polymer composites by comparing uncoated (Cu), silver-coated (Cu@Ag) and silica-coated (Cu@Si) copper flakes in low-density polyethylene at various volume concentrations (up to 40%). Interactions among particles were investigated by rheological properties, as these indicate network formation (geometrical entanglement), which is important for mechanical reinforcement as well as establishing an electric pathway (electrical percolation). The results showed that geometrical and electrical percolation were the same for Cu and Cu@Si, ~15%, while, surprisingly, Cu@Ag exhibited much lower percolation, ~7.5%, indicating the fusion of the Ag coating material, which also decreased crystal growth (degree of crystallinity). Furthermore, the magnitude of the rheological and mechanical response remained the same for all investigated materials, indicating that the coating materials do not provide any load transfer capabilities. However, they profoundly affect electron transfer, in that, Cu@Ag exhibited superior conductivity (74.4 S/m) compared to Cu (1.7 × 10$^{−4}$ S/m) and Cu@Si (1.5 × 10$^{−10}$ S/m). The results obtained are important for the design of advanced polymer composites for various applications, particularly in electronics where enhanced electrical conductivity is desired.

Keywords

polymer composites;copper flakes;silver coating;silica coating;percolation threshold;rheological properties;thermal properties;mechanical properties;electrical properties;

Data

Language:	English
Year of publishing:	2024
Typology:	1.01 - Original Scientific Article
Organization:	UL FS - Faculty of Mechanical Engineering
UDC:	539.3:678
COBISS:	198896899
ISSN:	2073-4360
Views:	479
Downloads:	85
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	Slovenian
Secondary keywords:	polimerni kompoziti;bakrene luske;srebrna prevleka;silicijeva prevleka;perkolacijski prag;reološke lastnosti;termične lastnosti;mehanske lastnosti;električne lastnosti;
Type (COBISS):	Article
Pages:	str. 1-14
Volume:	ǂVol. ǂ16
Issue:	ǂiss. ǂ12, [article no.] 1620
Chronology:	Jun. 2024
DOI:	10.3390/polym16121620
ID:	24314351