Upcycling of waste artificial turf forhigh‐performancewood‐plastic composites

Abstract

Plastic recycling is an essential tool to address the issue of plastic waste pollution. Unfortunately, current mechanical recycling processes for commingled plastic waste such as waste artificial turf (WAT) are limited by the inherent dilemma of separation challenge, high cost, and low‐quality products. In this work, solid‐phase shear milling (S3M) process was applied to prepare high‐performance WAT/wood flour (WF) composites, which addressed the challenges of poor compatibility and poor mechanical performance. Due to the strong shear force of S3M equipment, the strong hydrogen bonding in WF fibers was broken and the particle size of the WAT/WF mixture decreased from 452 to 47 μm. The well‐dispersed WF significantly improved the mechanical strength of WAT/WF composites from 17.6 to 26.4 MPa and melt processing ability. Moreover, the maximum tensile strength and modulus of the composites further improved to 32.6 and 2477 MPa through solid‐phase stretching with a 4% draw ratio. Compared with traditional WAT/WF composites, our research achieved the enhancement of 85.2% and 81.3% for tensile strength and modulus respectively. This work not only provides a promising strategy to resolve WAT environment pollution but also prepared value‐added high‐performance products for wood‐plastic applications.

High‐quality and efficient recovery of waste agricultural mulch film mixture via solid‐state shear milling technology

“…In the process, some hemicellulose and lignin, which are rich in hydroxyl groups, are separated from the surface of the cellulose, which causes a decrease in the number of hydroxyl groups and the ratio of A ( OH)/A ( CH 2 ). 16,30 The results of the x-ray photoelectron diffraction experiment also confirmed this view (Figure 9c,d). XPS was used to characterize the chemical elements and functional groups on the surface of the composite powder after milling.…”

“…Continuing to increase the number of millings nine times, the particle size distribution of the composite powder became narrower, but the average particle size changed little, only from 166.8 to 145 μm (Figure 3h). 16 Waste agricultural mulch film recovered from farmland will adsorb soil inorganic particles due to electrostatic action. 23,24 The microstructure of soil inorganic particles attached to the surface of polyethylene film before grinding was obtained by SEM (Figure 4a,b).…”

“…27,28 But with the help of solidstate-shear milling technology, the hydrogen bonds inside the lignified fiber can be destroyed, more free hydroxyl groups can be exposed, and the reaction accessibility can be increased. 16,29,30 The changes in chemical groups of powders with different milling times were characterized by infrared spectroscopy (Figure 5a). The broad peak in the region of 3500-3000 cm À1 was the stretching vibration peak of the cellulose hydroxyl group, and the hydrogen bond would make the peak move to the direction of low wavenumber.…”

“…The phase domain size can be controlled by the particle size and particle size distribution of the composite powder, which improves the compatibility of each component and the mechanical and processing properties of the products effectively. At present, the recycling of waste printed circuit board (WPCB) non-metallic powder, 14 automobile dismantling waste (ASR), 15 waste artificial turf (WAT), 16 and waste tire rubber (WTR) 17 has been realized by means of solid-state shear milling technology. It breaks through the limitation that the recovery of commingled plastics requires classification and separation and lays a foundation for the recycling and reuse of commingled plastics to prepare high-performance products.…”

Practicality of physical recycling method for waste polymer composites exampled via high density polyethylene/automobile shredder residue composites

“…ASR can reduce the viscosity and elasticity of the melt due to two aspects. First, the ASR components are processed by S 3 M, the molecular chains are broken by the strong shearing effect causing weakened intermolecular entanglement; at the same time, as demonstrated by the absence of plateau, there is no strong inter‐ and intramolecular force between ASR indicating rigid network was not generated during processing 36 …”