Preparation and Characterization of Synergistically Improved Thermally Conductive Polyamide 6 With Low Melting Point Metal and Low-Temperature Expandable Graphite

摘要

The effects of introduction of low-temperature expandable graphite (EG) and low melting point metal-tin (Sn) on the thermal conductivity (TC) of polyamide 6 (PA6) were investigated. After introducing 10 wt% of Sn as single filler, the TC of PA6 was nearly constant, while this value was dramatically increased to 5.187 W (mk)(-1) when 10 wt% of Sn was added into PA6/EG (40 wt%). The value was 90.1% higher than that of PA6/EG (40 wt%) composite, and 21.9% higher than that of PA6/EG (50 wt%), which suggested that the incorporation of EG and Sn had significant synergistic effect on the TC improvement of PA6. The electrical conductivity of the composite increased nearly 7 orders of magnitudes at the maximum filler content. Characterization of microstructure and energy spectrum analysis indicated that the dispersion of Sn in PA6/EG/Sn ternary composites was much more uniform than that of PA6/Sn binary composites. Differential scanning calorimetry measurement revealed that the crystalline peaks of Sn in PA6/EG/Sn composites disappeared and new exothermic peaks emerged at higher temperatures, which was mainly ascribed to the interaction between EG sheets and Sn. (C) 2016 Society of Plastics Engineers