Tunable Electrical Conductivity of Carbon-Black-Filled Ternary Polymer Blends by Constructing a Hierarchical Structure

• Main Authors: Qiyan Zhang, Bo-Yuan Zhang, Zhao-Xia Guo, Jian Yu
• Format: Article
• Language: English
• Published: MDPI AG 2017-08-01
• Series: Polymers
• Subjects: polymer composites; hierarchical structure; electrical conductivity; ternary blends; carbon black
• Online Access: https://www.mdpi.com/2073-4360/9/9/404
• ISSN: 2073-4360

A type of hierarchical structured composite composed of a minor thermoplastic polyurethane (TPU) phase spreading at the interface of two major phases polyoxymethylene/polyamide copolymer (POM/COPA) and carbon black (CB) particles selectively localized at the TPU/COPA interface of the tri-continuous blends was fabricated by melt compounding. The hierarchical structure was designed according to predictions and verified by a combination of electron microscopy and solvent extraction technique. The hierarchical structured composites show the dramatically decreased percolation threshold, a reduction of 60% compared to those without TPU where CB is selectively distributed in the COPA phase. The effects of CB contents and TPU on the phase morphology of POM/COPA were investigated, showing the occurrence of the POM/COPA phase inversion from a sea-island to a co-continuous structure beyond the percolation threshold of CB in the presence of TPU. The mechanism for the formation of conductive network is construction of CB network at the TPU/COPA interface of tri-continuous POM/COPA/TPU blends and double percolation effect.