Waste tires cause serious black pollution, and green, efficient recycling of waste tires is one of the key ways to solve this problem.This article proposes a twin-screw modification method and explores the influence of different twin-screw extrusion times on the modification effect of waste rubber powder (WRP). The modified WRP is flocculated with natural rubber latex to obtain the master rubber. The experimental results showed that after two rounds of twin-screw surface modification, the mechanical properties of WRP/natural rubber latex (NRL) composite materials were significantly improved compared to those without twin-screw surface modification. The tensile strength, tear strength, and elongation at break were increased by 19.44%, 27.36%, and 37.55%, respectively. In addition, the tensile strength retention rate and tear strength retention rate of the modified composite after aging are 78.26% and 76.43% respectively compared with those before aging, showing good anti-aging performance, which is of great significance for improving the service life and reliability of the composite.

Keywords: waste rubber powder, natural rubber, recycled rubber, twin-screw, desulfurization regeneration.