Preparation of composites based on recycled polypropylene and automotive shredder residue

Abstract

In past research, mechanical recycling of automotive shredder residue (ASR) has led to serious deterioration of material performance, and real-scale application in this way still remains a challenge. Here, we report a sustainable approach called solid-state shear milling (SSSM) for the production of high-performance polypropylene (PP)/ASR composites with robust mechanical performance on a commercial scale. After the SSSM process, the obtained 50/50 wt% PP/ASR composite exhibited a 41.3% increase in tensile strength, 32.9% increase in flexural strength and 55.0% increase in impact toughness when compared with corresponding composites made by traditional direct melt blending. In particular, the toughness of the material can be improved by further addition of PP grafted with maleic anhydride with toughness comparable to that of recycled PP, and a 325% increase in toughness can be obtained with addition of styrene-butadiene-styrene block copolymer grafted with maleic anhydride. This PP/ASR composite shows good processability and high thermal stability, and meets the requirements of many applications for nonstructural products. The approach presented in this paper highlights a novel technique for ASR recycling.

Novel Application of Mechanochemistry in Waste Epoxy Recycling via Solid-State Shear Milling

“…Compared with S3M-1, the flexural strength and non-notched impact strength of S3M-20 increased from 52.1 MPa, 4.2 kJ/m 2 to 73.2 MPa, 8.8 kJ/m 2 , which were increased by 41 and 109%, respectively (Figure c,d). For composites, the main way to absorb energy under external loads is the initiation and propagation of cracks . Large-sized WEP aggregates were prone to cause stress concentration and made the composites easy to wreck.…”

“…For composites, the main way to absorb energy under external loads is the initiation and propagation of cracks. 19 Large-sized WEP aggregates were prone to cause stress concentration and made the composites easy to wreck. In addition, the poor compatibility between the WEP-1 and epoxy matrix deteriorated the mechanical properties of the composites.…”

“…Landfills and incineration will not only cause serious environmental pollution but also are a great waste of resources, which is even more detrimental to the realization of carbon neutrality. In recent years, environmental legislation is becoming more and more restrictive, and some advanced countries have begun to ban epoxy landfills legally. The environmental impact of landfills and incineration is accelerating the urgency to develop recycling technology and meet the recycling rate. − …”

Effects of sulfonation on bis‐styrylbiphenyl fluorescent whitening agents for polypropylene

“…Characterized by stability, low price, and extensive adaptability, PP‐g‐MAH is a popular plastic . On the other hand, because of nonpolarity and high crystallinity, PP has poor compatibility with polar additives .…”

Rigid polyurethane foams reinforced with ultrafine powder from automotive shredder residue

“…With the development of automobile industry, lightweight body has gradually become the consensus of automobile design concepts, and hence polymeric materials featuring advantages of lightweight and high strength are widely used in modern automobile manufacturing 1,2 . However, compared with high‐valued metallic materials, these types of polymeric materials contained in discarded cars are too complicated and difficult to separate and recycle 3–5 . Specifically, automobile shredder residue (ASR), derived from the crushed end‐of‐life vehicles, is now becoming the most notorious waste in modern vehicle recycling industry and causing severe environmental problems due to accumulations of these harmful substances 6 …”