Thermal, mechanical and electrical properties of copper powder filled low-density and linear low-density polyethylene composites

• Published in: Polymer degradation and stability Vol. 91; no. 7; pp. 1629 - 1636
• Main Authors: Luyt, A.S., Molefi, J.A., Krump, H.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-07-2006; Elsevier Science
• Subjects: Applied sciences; Composites; Differential scanning calorimetry; Electrical conductivity; Exact sciences and technology; Forms of application and semi-finished materials; PE–Cu composites; Polymer industry, paints, wood; Technology of polymers; Tensile properties; Thermal conductivity; Thermogravimetric analysis; Differential scanning calorimetry; Thermal conductivity; Electrical conductivity; Thermogravimetric analysis; PE–Cu composites; Tensile properties; PE-Cu composites; Conducting material; Electrical properties; Thermal transition; Mechanical properties; Tensile property; Experimental study; Metal particle; Composite material; Thermal stability; Thermal properties; Low density ethylene polymer; Morphology; Concentration effect; Olefin polymer; Copper; Linear low density ethylene polymer
• ISSN: 0141-3910; 1873-2321
• DOI: 10.1016/j.polymdegradstab.2005.09.014

Low-density polyethylene (LDPE) and linear low-density polyethylene (LLDPE) with different copper contents were prepared by melt mixing. The copper powder particle distributions were found to be relatively uniform at both low and high copper contents. There was cluster formation of copper particles at higher Cu contents, as well as the formation of percolation paths of copper in the PE matrices. The DSC results show that Cu content has little influence on the melting temperatures of LDPE and LLDPE in these composites. From melting enthalpy results it seems as if copper particles act as nucleating agents, giving rise to increased crystallinities of the polyethylene. The thermal stability of the LDPE filled with Cu powder is better than that for the unfilled polymer. The LLDPE composites show better stability only at lower Cu contents. Generally, the composites show poorer mechanical properties (except Young's modulus) compared to the unfilled polymers. The thermal and electrical conductivities of the composites were higher than that of the pure polyethylene matrix for both the LDPE and LLDPE. From these results the percolation concentration was determined as 18.7
vol.% copper for both polymers.