Ultra‐high molecular weight polyethylene (UHMWPE) foam materials have significant potential for various applications due to their outstanding properties. However, their high molecular weight and poor fluidity present challenges in the foaming process. To address this issue, UHMWPE was utilized as the matrix, while low‐density polyethylene (LDPE) served as the flow modifier. Mica, calcium carbonate (CaCO 3 ), and kaolin were incorporated as inorganic fillers. The UHMWPE/LDPE composite foams were prepared using open mill plasticization combined with flat plate compression foaming. The effects of foaming agent dosage, LDPE content, and the type and amount of filler on the apparent density, mechanical properties, thermal properties, and cellular microstructure of the foam were systematically investigated. This was achieved through orthogonal experiments, response surface analysis, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and various other testing methods. The results indicate that LDPE effectively enhances the fluidity of UHMWPE, with its content having a non‐linear impact on the foam’s apparent density. The optimal dosage of the foaming agent was found to be 6 parts per hundred resin (phr), leading to a minimum apparent density of 0.42 g·cm -3 when the LDPE content was 40 phr. The addition of all three types of fillers improved the mechanical properties and thermal stability of the foam; in particular, kaolin demonstrated the best reinforcing effect due to its fine particle size and layered structure, achieving a maximum tensile strength of 6.21 MPa in the filled foam. SEM observations revealed that the fillers refine the cell structure, with mica and kaolin, both featuring layered structures, exhibiting better nucleation effects compared to CaCO 3 , which has an irregular shape. The findings from response surface analysis and orthogonal experiments suggest that the optimal formulation for low‐density UHMWPE/LDPE composite foam is composed of UHMWPE as the matrix, LDPE at 30‐40 phr, CaCO 3 at 15‐20 phr, a foaming agent at 6 phr, dicumyl peroxide (DCP) at 0.3 phr, and antioxidant 1010 at 1 phr. This study provides both theoretical support and technical guidance for the industrial production and application of UHMWPE foam materials.
Liao et al. (Thu,) studied this question.