Properties of polyphenylene sulphide/glass fibre composites with negative thermal expansion ceramic fillers

The high coefficient of thermal expansion (CTE) of polymeric composites can cause large deformation under temperature changes, affecting coupling with devices made of other materials in radio frequency (RF) communication systems and limiting their application in RF systems. In order to obtain polyphenylene sulphide (PPS)-based composites with low CTE, a series of PPS-based composites containing different loadings of ceramic powders (including Zr2WP2O12, BN, AlN, Al2O3) were fabricated by melt extrusion method using PPS with 40 wt% glass fibre (GF) as matrix material. The experimental results showed that the PPS composites with Zr2WP2O12 (ZWP) as a filler had a lower CTE compared to the samples with other fillers at the same filler loading. The CTE of PPS/GF/ZWP steadily decreased with increasing ZWP addition. At 20 vol% ZWP loading, a 67% (about 18 ppm/°C) reduction of CTE compared to the PPS/GF was achieved. The addition of ZWP powder to PPS/GF also led to an improvement in the dielectric loss of the composite. When the ZWP content is 20 vol%, the dielectric loss of the composites is about 0.0035, which is 24.4% lower than PPS/GF. Hence, the PPS/GF/ZWP composites have great potential for applications in RF communication systems.