Synergistic functionalized polyethylene/attapulgite composites with maleic anhydride and silicone by reactive extrusion for enhanced metal-plastic interfacial adhesion

Abstract To enhance both the adhesive strength and cohesion of the adhesive resin, attapulgite functionalized with peroxy groups (ATP-CPO) was prepared through surface chemical modification. Subsequently, a series of polyethylene/ATP composites (PE/ATP) functionalized with maleic anhydride and vinyl trimethoxysilane were prepared via surface-initiated graft copolymerization. The effects of ATP-CPO dosage on the mechanical, thermal, rheological, and morphological characteristics of the composites were evaluated in detail. It was found that the surface functionalization and reactive extrusion process contributed to the nano-scale dispersion of ATP in the PE matrix, forming well-compatibilized nanocomposites consisting of PE-g-(MAH-co-VTMS), ATP-g-(MAH-co-VTMS), and more complex MAH/VTMS synergistically functionalized ATP-g-PE. When the ATP-CPO content was 4%, the composite exhibited significantly enhanced tensile strength, peel strength, and shear strength, which were 1.4, 26.3, and 21.7 times higher than those of pure PE, respectively. Concurrently, the composites displayed higher melting and crystallization temperatures. However, the crystallinity decreased slightly, while the thermal stability was significantly improved. The melt exhibited more pronounced non-Newtonian behavior. Compared to the loss modulus, the storage modulus increased more significantly in the low-frequency region, and a non-terminal effect was observed, which enhanced the structural stability of the system under low-frequency shear stress.