On the Kinetics of Degradation Reaction Determined Post Accelerated Weathering of Polyolefin Plastic Waste Blends

Abstract

Polyolefin (PO) polymers constitute the majority of consumer plastic commodities. The reliance on such materials make it near imposable to avoid touching one in any given day. Therefore, the accumulation of plastic solid waste (PSW) in developed and developing societies alike requires immediate attention to manage and valorize this type of waste. In this work, PSW originating from real life sources and virgin linear low-density polyethylene (LLDPE) films were compounded in a mechanical recycling effort. The recycled blends constituted up to 100% (by weight) of the waste material. Accelerated weathering (aging) was conducted on the blends, reaching threshold limit of exposure to study the major changes occurring on the recycled blends. Thermogravimetry and differential scanning calorimetry (DSC) were used to determine their characteristics and applicability for future recycling using thermo-chemical treatment (TCT) methods. Analytical solution methods following the international committee of thermal analysis and calorimetry (ICTAC) were followed in conducting the measurements and kinetic calculations alike. A novel analytical mathematical solution model is also introduced to determine both the pre-exponential factor (Ao) and apparent activation energy (Ea) of the degradation reaction. The model proved to be a more accurate analysis tool, and the work in whole enabled the determination of future plans for using such waste components as a feedstock to thermal units.

Pyro-Oil and Wax Recovery from Reclaimed Plastic Waste in a Continuous Auger Pyrolysis Reactor

“…The four dominant components by weight (and also colour) in the material showed distinctive thermograms that could be attributed to various components of plastic solid waste (PSW) typically available in the municipal stream [1,24,25] (Figure S2). The onset and endset temperatures (identified by the thermograms) associate these components with rigid (hard) plastics (e.g., PS), mixed municipal plastic waste (MPW) (e.g., mixture of PE, PET, PS etc), plastic film waste (PFW) (e.g., LDPE) and end of life tyre (ELTs) [18,25,26] (Figure S3.a.). The majority of the materials were also previously identified as polyolefinic (PO) polymers in origin, namely polyethylene (PE) [25].…”

“…The onset and endset temperatures (identified by the thermograms) associate these components with rigid (hard) plastics (e.g., PS), mixed municipal plastic waste (MPW) (e.g., mixture of PE, PET, PS etc), plastic film waste (PFW) (e.g., LDPE) and end of life tyre (ELTs) [18,25,26] (Figure S3.a.). The majority of the materials were also previously identified as polyolefinic (PO) polymers in origin, namely polyethylene (PE) [25]. Readers are referred to our previous results and discussion detailed in Al-Salem et al [18,24].…”

Wax Recovery from the Pyrolysis of Virgin and Waste Plastics

“…Furthermore, plastic solid waste (PSW) can be argued to be the least problematic of various solid waste components since polymer production only consumes approximately 4–8% of petroleum . Nonetheless, PSW management is quite essential for other aspects that touch upon environmental burden reduction, such as landscape deterioration, environmental sink pollution, microplastic accumulation, and landfill space reduction. − …”

“…Secondly, TCC is quite effective in valorizing plastics to produce fuel-range chemicals such as gasoline and diesel . Thirdly, it advocates a clean and green practice of fuel production and resource management, which is governed by a fluctuating market due to unstable crude oil prices . Lastly, TCC is quite effective in treating polyolefin plastics to produce value-added products, including chemical waxes and solid char. − Polyolefin plastics make up the majority of municipal plastic waste, of which low-density polyethylene (LDPE), high-density polyethylene (HDPE), polypropylene (PP), and linear low-density polyethylene (LLDPE) make a hefty proportion (estimated at 65%) .…”