PET Waste Research Articles

Influence of the Presence of Poly(butylene succinate) in the Poly(ethylene terephthalate) Recycling Process

Poly(butylene succinate) (PBS) is one of the contaminants in the Poly(ethylene terephthalate) (PET) recycling process. It is known that high contents of PBS in PET significantly reduce PET properties, but the effect of low contents on PET has yet to be studied. This work studied the influence of low contents of PBS on recycled PET. Five formulations of PBS in PET were prepared, and the properties of relative affinity, mechanical, thermal, and disintegration under composting conditions were assessed. The solubility parameter indicated that PET and PBS are miscible. However, FESEM images show slight marks of immiscibility, and the mechanical characterization results showed that PBS, even in low contents, reduced the mechanical properties of recycled PET, which proves that the materials are not miscible in the studied contents. The DSC results indicated that PBS could not be quickly detected in PET. However, its presence can be inferred by the reduction in PET crystallization degree. Finally, the presence of PBS up to 15 wt.% does neither affect the disintegration under composting conditions nor the thermal stability of recycled PET. The drop in mechanical properties shows that PBS must be removed from the PET waste stream to preserve the quality of the material.

In situ nanofibrillation of polypropylene/polyethylene/poly(ethylene terephthalate) ternary system: A strategy of upgrade recycling

Upgrade recycling of multicomponent polymer blends remains a great challenge due to the inherent immiscibility of most polymer combinations. Herein, we report a new and efficient strategy potential for upgrade recycling of polypropylene/polyethylene/poly(ethylene terephthalate) (PP/PE/PET) ternary system, through in situ nanofibrillation of PET with the aid of extrusion-hot stretching and further annealing stretching. PET fibrils with high aspect ratios are achieved in the ternary blends by extrusion-hot stretching, and adding compatibilizer and further annealing stretching reduce the average diameter of PET fibrils down to as low as 240 nm. The PET nanofibrils suppress the relaxation of orientated structure during the hot stretching progress, which increases the orientation factor of PP from 0.08 to 0.30. During further annealing stretching, the PP molecular chains are highly oriented under the extensional flow field and PE grows epitaxially on the oriented PP substrate regardless of the presence of PET nanofibrils, promoting the interfacial adhesion between PP and PE. The high orientation of PP and PE, the epitaxial crystalline structure and PET nanofibrils impart remarkably enhanced tensile strength (up to 481.2 MPa), elasticity modulus (up to 4.85 GPa) and elongation at break (up to 1004.9%) to the PP/PE/PET ternary blends. This work could provide significant guidance for the high-performance processing and upcycling of waste PP, PE and PET materials.

Optimization process for glycolysis of poly (ethylene terephthalate) using bio-degradable & recyclable heterogeneous catalyst

Because of characteristics including simplicity of processing, light weight, recyclability, and low cost of production, plastic production and usage have risen every day. As a result, there is now more waste plastic generated every day, and it will be opening up a brand-new field of study for researchers to investigate and solve these issues. An ecologically friendly approach is needed to solve these problems. One approach is to recycle this kind of waste. There are several ways to recycle used plastics, but practically all of them have good and bad points. About a few decades ago, the glycolysis of used PET polymers gained industrial attention. Since used poly (ethylene terephthalate) (PET) plastics may be recycled using the most advantageous and promising techniques. This works an optimization parameter of chemical recycling of PET waste without utilizing any solvent as a reaction medium by changing a number of variables, such as catalyst types and the molar ratio of EG: PET, catalyst ratio and also recycled catalyst and reagent. The recovered Bio-catalyst (OPA/BLA) still maintained excellent catalytic efficiency for PET Glycolysis after six consecutive cycles. Optimized reaction condition was PET:EG (1:16) molar ratio 1% w/w catalyst at 192–200 °C reaction temperature obtaining 60.32% Yield of BHET product at 98.40% of PET conversion. Final product was confirmed by FT-IR, 1H NMR and GC-MS data.

Preparation of Carbon Dots from PET Waste by One-step Hydrothermal Method and its Application in Light Blocking Films and LEDs.

An environmentally friendly PET-based Carbon Dots (PET-CDs) with excellent fluorescence properties were prepared with waste PET bottle, pyromellitic acid and ammonia water as raw materials by one-step hydrothermal method. The preparation mechanism of PET-CDs was as follows: PET first underwent ammonolysis reaction to produce terephthalic acid diamide and ethylene glycol, and then dehydrated and carbonized with pyromellitic acid to form PET-CDs. The as-prepared PET-CDs exhibit excitation-independent emission properties in the range from 340 to 440nm, and the fluorescence quantum yield is as high as 87.36%. In terms of structure, PET-CDs is a spherical structure with an average particle size of 2.0nm, and its surface contains carboxyl and amino groups. The PET-CDs were dispersed in a PVA matrix to obtain an light blocking films(LBFs) for 250-450nm light with excellent properties, and its transparency for 450-700nm light is good. In addition, PET-CDs was used in the fields of LED, and it was found that the color coordinate for the LED assembled with PET-CDs and 395nm LED chips is (0.55, 0.44) and the correlated color temperature is 2018K.

New photoinitiators derived from PET waste: Molecular simulations and photocatalytic efficiency

New photoinitiators derived from PET waste: Molecular simulations and photocatalytic efficiency

Facile synthesis of accordion-like porous carbon from waste PET bottles-based MIL-53(Al) and its application for high-performance Zn-ion capacitor

It is of great scientific and economic value to recycle waste poly (ethylene terephthalate) (PET) into high-value PET-based metal organic frameworks (MOFs) and further convert it into porous carbon for green energy storage applications. In the present study, a facile and cost-effective hydrothermal process was developed to direct recycle waste PET bottles into MIL-53(Al) with a 100% conversation, then the MOF-derived porous carbon was assembled into electrodes for high-performance supercapacitors. The results indicated that the as-synthesized carbon exhibited high SSA of 1712 m2 g−1 and unique accordion-like structure with hierarchical porosity. Benefit to these advantageous characters, the assembled three-electrode supercapacitor displayed high specific capacitances of 391 F g−1 at the current density of 0.5 A g−1 and good rate capability of 73.6% capacitance retention at 20 A g−1 in 6 mol L−1 KOH electrolyte. Furthermore, the assembled zinc ion capacitor still revealed outstanding capacitance of 335 F g−1 at 0.1 A g−1, excellent cycling stability of 92.2% capacitance retention after 10 000 cycles and ultra-high energy density of 150.3 Wh kg−1 at power density of 90 W kg−1 in 3 mol L−1 ZnSO4 electrolyte. It is believed that the current work provides a facile and effective strategy to recycle PET waste into high-valuable MOF, and further expands the applications of MOF-derived carbons for high-performance energy storage devices, so it is conducive to both pollution alleviation and sustainable economic development.

Solvent-thermal preparation of sulfur and nitrogen-doped carbon dots with PET waste as precursor and application in light-blocking film

Solvent-thermal preparation of sulfur and nitrogen-doped carbon dots with PET waste as precursor and application in light-blocking film

β-Ketoadipic acid production from poly(ethylene terephthalate) waste via chemobiological upcycling.

The upcycling of poly(ethylene terephthalate) (PET) waste can simultaneously produce value-added chemicals and reduce the growing environmental impact of plastic waste. In this study, we designed a chemobiological system to convert terephthalic acid (TPA), an aromatic monomer of PET, to β-ketoadipic acid (βKA), a C6 keto-diacid that functions as a building block for nylon-6,6 analogs. Using microwave-assisted hydrolysis in a neutral aqueous system, PET was converted to TPA with Amberlyst-15, a conventional catalyst with high conversion efficiency and reusability. The bioconversion process of TPA into βKA used a recombinant Escherichia coli βKA expressing two conversion modules for TPA degradation (tphAabc and tphB) and βKA synthesis (aroY, catABC, and pcaD). To improve bioconversion, the formation of acetic acid, a deleterious factor for TPA conversion in flask cultivation, was efficiently regulated by deleting the poxB gene along with operating the bioreactor to supply oxygen. By applying two-stage fermentation consisting of the growth phase in pH 7 followed by the production phase in pH 5.5, a total of 13.61 mM βKA was successfully produced with 96% conversion efficiency. This efficient chemobiological PET upcycling system provides a promising approach for the circular economy to acquire various chemicals from PET waste.

How introduction of deposit-refund system (DRS) changes recycling of non-drinking bottle PET wastes

How introduction of deposit-refund system (DRS) changes recycling of non-drinking bottle PET wastes

Sodium ethoxide as an environmentally benign and cost-effective catalyst for chemical depolymerization of post-consumer PET waste

Sodium ethoxide, a cost-effective catalyst, completely outperforms the hitherto studied catalysts making large-scale PET depolymerization processes possibly far more sustainable.

Fabrication and characterisation of epoxy-based composite utilising PET waste plastic and bamboo

Fabrication and characterisation of epoxy-based composite utilising PET waste plastic and bamboo

Chemical recycling of PET to value-added products

This review has focused on the concept of upcycling, which involves utilizing PET waste as a raw material for the production of value-added products such as monomers, fine chemicals, hydrogen, or carbon materials.

Simultaneous upcycling of PET plastic waste and CO2 reduction through Co-electrolysis: a novel approach for integrating CO2 reduction and PET hydrolysate oxidation

The paper reports on the concurrent electrochemical generation of formate through CO2 reduction (cathode) and polyethylene terephthalate (PET) hydrolysate oxidation (anode).

Optimization of TiO(acac)2 for efficient catalytic alcoholysis of waste PET using response surface methodology

Acetylacetone titanium oxide (TiO(acac)2) was synthesized from acetylacetone and isopropyl titanate via a one-pot method.

Selective electro-reforming of waste polyethylene terephthalate-derived ethylene glycol into C2 chemicals with long-term stability

We present an approach based on segregation-less Pd1Ag1 alloy nanoparticles (NPs) for the electro-reforming of waste PET into glycolate C2 products with high selectivity (97%) and long-term stability (>500 h).

Solvent based dissolution–precipitation of waste polyethylene terephthalate: economic and environmental performance metrics

Evaluating six economic and two environmental performance metrics for recycling of waste PET via solvent-based dissolution–precipitation processes.

Waste PET upcycling to conductive carbon-based composite through laser-assisted carbonization of UiO-66

The upcycling of waste polymers into novel materials with high added value is a vital task for modern chemical engineering.

Upcycling of poly(ethylene terephthalate) to produce high-value bio-products

More than 70 million tons of poly(ethylene terephthalate) (PET) are manufactured worldwide every year. The accumulation of PET waste has become a global pollution concern, motivating the urgent development of technologies to valorize post-consumer PET. The development of chemocatalytic and enzymatic approaches for depolymerizing PET to its corresponding monomers opens up new opportunities for PET upcycling through biological transformation. Here, we identify Rhodococcus jostii strain PET (RPET) that can directly use PET hydrolysate as a sole carbon source. We also investigate the potential of RPET to upcycle PET into value-added chemicals, using lycopene as a proof-of-concept product. Through rational metabolic engineering, we improve lycopene production by more than 500-fold over that of the wild type. In addition, we demonstrate the production of approximately 1,300μg/L lycopene from PET by cascading this strain with PET alkaline hydrolysis. This work highlights the great potential of biological conversion as a means of achieving PET upcycling.

Exploration of PET and HDPE Plastic Waste into the Art Creating of Lampshade with Geometric Shape

Nowadays, waste has become a problem faced by people worldwide, especially in Indonesia. Wastes that are difficult to process, like plastics, can disturb environmental aesthetics, environmental cleanliness, and health. They have a power that is difficult to decipher, so the researcher applied several methods to them. Through an experimental process, this research designed the products of lighting elements for cafés made of plastic bottles in the types of PET and HDPE. Several phases in the testing process must be carried out to convert the wastes. First, data collection was then continued by the experiment process to produce design synthesis. In the design process, the researcher conducted waste collection, sorting, milling, washing, forming, and finishing processes. This research involved 3 sites for case studies, namely Blimbing Village TPS, Robbries Gallery as a place to search for data on waste processing processes, and Akarating Café as a theme and also as a place to look for observation data. The experimental process yielded lights used in a cafe having a hexagon shape with 2 different color accents and having different placements, such as hanging on the roof and sticking on the wall.

Solvothermal preparation of nitrogen-doped carbon dots with PET waste as precursor and their application in LEDs and water detection

Developing novel, alternative ways to recycle PET waste, which has an important influence on reduction of landfilling and CO2 emissions, has always been a research hot spot for industry and academy. In this work, PET waste was adopted as precursor for the preparation of nitrogen-doped Carbon Dots (NCDs). Firstly, PET oligomers were obtained by alcoholysis of PET waste with ethylene glycol. Then, the mixture without isolation and purification as well as pyromellitic acid dianhydride and urea were adopted as precursors for the preparation of NCDs by solvothermal method with tetrahydrofuran (THF) as solvent. The as-prepared NCDs has a spherical structure with an average particle size of 2.3 nm. What is more, NCDs exhibit excitation-independent emission properties, the largest excitation peak and emission peak of NCDs located in 360 nm and 470 nm, and the fluorescence quantum yield is 48.16 %. In term of application, NCDs are dispersed in PMMA and loaded on 365 nm and 430 nm LED chips to obtain LED devices emitting yellow light ((0.55, 0.44), 2018 K) and warm white light ((0.37, 0.31), 3783 K), respectively. In addition, NCDs could be adopted as fluorescent probe for the construction of sensor for water in organic solvents based on dynamic quenching of NCDs, and the limit of detection (LOD) is 0.00001 %.