Polypropylene/epoxy/synthetic graphite (PP/EP/SG) and high-density polyethylene (HDPE/EP/SG) composites were prepared by melt mixing followed by compression molding. The immiscibility of the polyolefins with epoxy was confirmed by thermogravimetric analysis. Scanning electron microscopy (SEM) studies showed that HDPE/EP blend exhibits inferior interfacial adhesion between the component polymers compared to PP/EP blend. Also, the effect of SG content on flexural properties, density, moldability, water absorption, and porosity of the PP/EP/SG and HDPE/EP/SG composites was investigated. For both PP/EP/SG and HDPE/EP/SG composites, flexural modulus, density, and porosity increased with increase in SG content. For PP/EP/SG composites, the water absorption decreased from 0.154% at 30 wt% SG to 0.072% at 70 wt% SG. Further increase in SG content to 80 wt% caused an increase in water absorption. On the other hand, water absorption for HDPE/EP/SG increased with SG content all through. At the same filler loadings, PP/EP/SG composites showed lower density and porosity and performed better in terms of flexural modulus and water absorption compared to HDPE/EP/SG composites.

聚丙烯/环氧树脂/合成石墨（PP/EP/SG）和高密度聚乙烯（HDPE/EP/SG）复合材料通过熔融混合和压缩成型制备。通过热重分析证实了聚烯烃与环氧树脂的不混溶性。扫描电子显微镜 (SEM) 研究表明，与 PP/EP 共混物相比，HDPE/EP 共混物在组分聚合物之间的界面粘合性较差。此外，研究了 SG 含量对 PP/EP/SG 和 HDPE/EP/SG 复合材料的弯曲性能、密度、成型性、吸水率和孔隙率的影响。对于 PP/EP/SG 和 HDPE/EP/SG 复合材料，弯曲模量、密度和孔隙率随着 SG 含量的增加而增加。对于 PP/EP/SG 复合材料，吸水率从 30 wt% SG 时的 0.154% 降至 70 wt% SG 时的 0.072%。SG 含量进一步增加到 80 wt% 导致吸水率增加。另一方面，HDPE/EP/SG 的吸水率始终随着 SG 含量的增加而增加。在相同的填料用量下，与 HDPE/EP/SG 复合材料相比，PP/EP/SG 复合材料的密度和孔隙率更低，并且在弯曲模量和吸水率方面表现更好。