Abstract: A type of composite foams was fabricated by using low-density polyethylene （PE-LD） and high-density polyethylene （PE-HD） as matrix resins， calcium sulfate whisk （CSW） as a reinforcing agent， and azodicarbonamide as a foaming agent. The effect of CSW content on the melt flow rate， thermal properties， foaming behavior， mechanical properties， thermal conductivity， and thermal stability of the PE-LD/PE-HD/CSW blends were investigated. The results indicated that the introduction of CSW reduced the melt flow rate of the blends but improved their thermal stability. Compared to pure PE-LD/PE-HD complex foam， the PE-LD/PE-HD/CSW complex foams obtained better comprehensive properties at a CSW content of 8 wt%. Under such a CSW loading， the complex foams achieved an increase in tensile strength by 21.3 %， in compression strength by 17.8 %， in compression modulus by 31.3 %， in hardness by 10.9 %， and in tear strength by 16.4 %， but a decrease in thermal conductivity by 15.5 %.

Key words: polyethylene, calcium sulfate whisk, mechanical property, thermal stability, foam behavior