文章利用硅烷偶联剂（KH-570）改性纳米SiO₂（nano-SiO₂），将nano-SiO₂与高密度聚乙烯（HDPE）混合，制备了HDPE/nano-SiO₂复合材料。对HDPE/nano-SiO₂复合材料的力学性能和耐热性能进行探究。结果表明：KH-570成功接枝到nano-SiO₂表面。随着nano-SiO₂掺量的增加，HDPE/nano-SiO₂复合材料的拉伸强度、弯曲强度和冲击强度均先升高后降低。当nano-SiO₂掺量为3%时，HDPE/3%nano-SiO₂复合材料的力学性能和耐热性能达到最优，其拉伸强度、弯曲强度和抗冲击强度，分别达到39.6 MPa、32.5 MPa和16.9 kJ/m²，比纯HDPE分别提高了73.7%、59.3%和36.3%。HDPE/3%nano-SiO₂复合材料的初始热分解温度比纯HDPE提高了101 ℃，质量保留率为6.2%。

The HDPE/nano-SiO₂ composites were prepared using silane coupling agent (KH-570) to modify nano-SiO₂ and mix nano-SiO₂ with high-density polyethylene (HDPE). The mechanical properties and heat resistance of HDPE/nano-SiO₂ composites were explored. The results showed that KH-570 was successfully grafted onto the surface of nano-SiO₂. With the increase of nano-SiO₂ content, the tensile strength, flexural strength and impact strength of HDPE/nano-SiO₂ composites first increased and then decreased. When the nano-SiO₂ content is 3%, the mechanical properties and heat resistance of HDPE/3%nano-SiO₂ composites reach the best, and their tensile strength, bending strength and impact strength reach 39.6 MPa, 32.5 MPa and 16.9 kJ/m², respectively, which are 73.7%, 59.3% and 36.3% higher than those of pure HDPE, respectively, and the initial thermal decomposition temperature of HDPE/3%nano-SiO₂ composites is increased by 101 ℃ compared with pure HDPE, the quality retention rate of HDPE/3%nano-SiO₂ is 6.2%.