Plastic Mixtures Research Articles

Catalytic Pyrolysis of a Model Plastic Mixture with a Montmorillonite Clay Catalyst and Upgrading via Distillation

Catalytic Pyrolysis of a Model Plastic Mixture with a Montmorillonite Clay Catalyst and Upgrading via Distillation

Simulation-Based Design for Recycling of Car Electronic Modules as a Function of Disassembly Strategies

Modules (or parts) of a car are a complex functional material combination used to deliver a specified task for a car. Recovering all materials, energy, etc., into high-grade materials at their end of life (EoL) is impossible. This is dictated by the second law of thermodynamics (2LT) and thence economics. Thus, recyclability cannot be conducted with simplistic mass-based approaches void of thermodynamic considerations. We apply, in this paper, a process simulation model to estimate the true recyclability of various SEAT (Volkswagen Group) car parts within the EU H2020 TREASURE project. This simulation model is developed with 190 reactors and over 310 feed components with over 1000 reaction species in the 880 streams of the flowsheet. The uniqueness of the work in this paper is to apply the full material declaration (FMD) and bill of materials (BOM) of all 310 materials in the parts as a feed to the process simulation model to show the parts’ true recyclability. We classified all parts into categories, i.e., copper-rich, steel-rich and plastic-rich, to maximally recover metals at the desired material quality, as well as energy. Recyclability is understood to create high-grade products that can be applied with the same functional quality in these parts. In addition, disassembly strategies and related possible redesign show how much recyclability can be improved. Process simulation permits the creation of alloys, phases, materials, etc., at a desired quality. The strength of the simulation permits any feed from any End-of-Life part to be analyzed, as long as the FMD and BOM are available. This is analogous to any mineral and metallurgical engineering process simulation for which the full mineralogy must be available to analyze and/or design flowsheets. This paper delivers a wealth of data for various parts as well as the ultimate recovery of materials, elements, and energy. The results show clearly that there is no one single recycling rate for elements, materials, and alloys. It is in fact a function of the complexity and material combinations within the parts. The fact that we use a thermochemical-based process simulator with full compositional detail for the considered parts means full energy balances as well as exergy dissipation can be evaluated. This means that we can also evaluate which parts, due complex mixtures of plastics, are best processed for energy recovery or are best for material and metal recovery, with thermochemistry, reactor technology and integrated flowsheets being the basis.

Transformative and sustainable approach to waste plastic mixture valorization

The development of innovative methods for waste plastic valorization can benefit the environment and economy. In this study, the full spectrum of products (gas, oil, and solid products) resulting from the pyrolysis–reforming of a plastic mixture functioned as precursors of value-added products: 1) ethylene–propylene copolymers, 2) polyacrylonitrile (PAN)-based carbon nanofibers (CNFs), and 3) carbon quantum dots (CQDs). The CNFs were subsequently applied as supercapacitor electrodes, whereasthe CQDs acted as co-sensitizers for the primary sensitizer, N3, in dye-sensitized solar cells (DSSCs). Adding oil to PAN increased the specific capacitance of the CNFs by 46.12% to 226.64F/g, compared with that of pure PAN CNFs. With the aid of CQDs, the short-circuit current density and photo-conversion efficiency of DSSCs increased by 25.89% and 17.08%, respectively. Mechanisms associated with the integrated valorization pathway were proposed.

Reversible Vitrimisation of Single‐Use Plastics and their Mixtures

AbstractVitrimers are promising next‐generation materials, often exhibiting superior properties such as mechanical strength and solvent resistance compared to their thermoplastic counterparts, while still featuring recyclability due to their dynamic covalent crosslinks. The most common strategy to recycle vitrimers is via mechanical reprocessing at high temperatures, while others utilize chemical degradation to reobtain the constituent monomers. This work presents a new approach toward reprocessing by selectively breaking of the vitrimer's crosslinks, turning it back into a thermoplastic. This allows for reprocessing to be achieved in a more sustainable manner such as at lower temperatures and shorter times. After the desired shape has been obtained, facile re‐crosslinking turns the material into a vitrimer, with full restoration of thermal stability, mechanical properties, and gel fraction. To achieve this, a carbene C─H insertion strategy is utilized to introduce an imine‐based crosslinker into various thermoplastics and plastic mixtures to convert them into vitrimers. Properties typical of vitrimers such as a retained polymer network at high temperatures, and an Arrhenius‐type relationship between stress relaxation rate and temperature are observed, while its mechanical properties such as elongation at break and tensile toughness, particularly for plastic mixtures are significantly enhanced, first by crosslinking, then further enhanced up to 8 folds by the reversible crosslinking process.

Strategic conversion of plastic containers with food waste into energy through thermochemical processes

Plastic valorization has received particular attention as an environmentally benign approach to achieve carbon neutrality and reduce greenhouse gas emissions. However, contaminated plastic and biomass waste mixtures suffer from single-stream recycling. Waste mixtures are currently discarded through landfilling and incineration. As a sustainable disposal and valorization method for converting plastic and biomass waste mixtures into energy-intensive products, especially syngas (H2 and CO), this study utilizes catalytic pyrolysis and a CO2 flow gas. A plastic container contaminated with a food waste mixture (PFW) was used as the model waste. The major products of the pyrolysis of PFW were liquid hydrocarbons (HC) (C7–30) and wax-like HCs with negligible formation of oxygen-containing HCs. However, the high production of wax-like HCs becomes a problem. Catalytic pyrolysis was employed to convert HCs into simpler product streams such as syngas. Although syngas formation tripled with the Ni catalyst, catalyst deactivation was observed. To suppress catalyst deactivation and promote CO formation, CO2 was introduced instead of N2. During the CO2-assisted catalytic pyrolysis, the syngas yield from PFW increased to 95.5 % because the chemical reactions between CO2 and liquid/wax-like HCs produced additional H2 and CO. The catalytic reaction with CO2 suppressed carbon deposition because long-chain HCs were converted to CO rather than coke.

Human skin absorption of three plasticizers: Diisononyl-1,2-cyclohexanedicarboxylate (DINCH), di(2-ethylhexyl) terephthalate (DEHTP), and di(2-ethylhexyl) adipate (DEHA)

Alternative plasticizers such as diisononyl-1,2-cyclohexanedicarboxylate (DINCH), di(2-ethylhexyl) terephthalate (DEHTP), and di(2-ethylhexyl) adipate (DEHA) are progressively replacing phthalates in many consumer and professional products because of adverse effects on reproduction associated with some phthalates. Human exposures to these phthalate substitutes can occur through ingestion, skin absorption and inhalation. Skin uptake can lead to greater concentration at the target organs compared to ingestion because the skin exposure route bypasses the first-pass effect. Skin absorption studies are almost absent for these alternative plasticizers. We therefore wanted first, to characterize skin absorption of a mixture containing DINCH, DEHA and DEHTP in vitro using a flow-through diffusion cell system with ex vivo human skin, quantifying their respective monoester metabolites (mono-isononyl-cyclohexane-1,2-dicarboxylate (MINCH), mono-2-ethylhexyl adipate (MEHA), mono-2-ethylhexyl terephthalate (MEHTP), respectively); second, to validate these results by exposing five human volunteers to this mixture on their forearm and quantifying the corresponding urinary metabolites (including the monoesters and their oxidation products). Our study showed that two of these alternative plasticizers, DEHTP and DINCH, did not permeate skin showing as quantifiable metabolite levels in vitro and only traces of DEHA were quantified as its monoester metabolite, MEHA. Permeation coefficient (Kp) 0.06 and 55.8*10−7 cm/h for neat and emulsified DEHA, respectively, while the permeation rate (J) remained low for both (0.005 and 0.001 µg/cm2/h, respectively). Participants exposed to a mixture of these three plasticizers did not have noteworthy urinary concentrations of their respective metabolites after 24 hours post-application. However, the alternative plasticizer mixture was completely absorbed after six hours post-application on the forearms of the human volunteers, and the urinary elimination curves showed a slight increase after 24 hours post-application. Further studies on skin absorption of these substances should follow the urinary elimination kinetics of these metabolites more than 24 hours post-application. We also recommend quantifying the parent compounds in the in vitro diffusion experiments.

Hydrothermal liquefaction of plastic marine debris from the North Pacific Garbage Patch

Ocean plastic waste poses a growing environmental threat, efforts are now underway to help clean the ocean surface or to prevent plastic streams entering. Repurposing these highly mixed polymers presents a great challenge due to their inherent complexity, intertanglement, and the presence of contaminants. Herein, we process real samples of ocean-floating plastics from the North Pacific Garage Patch through supercritical hydrothermal liquefaction (HTL), targeting their chemical recycling into synthetic crude oil. Investigating key process parameters (temperature, pressure, time, and plastic load), we found that plastic load and temperature are crucial parameters influencing oil yield and that moderate conditions maximized hydrocarbon yield, reaching 90 wt%. Overall, longer residence times and higher temperatures favored aromatic-rich oils. We suggest a reaction pathway to account for hydrogen release from aromatization reactions, influencing paraffin, olefin, and aromatic contents. Supercritical HTL offers an effective, tailored approach for recycling complex plastic mixtures to produce synthetic crude oil.

Experimenting the effectiveness of waste materials in improving the compressive strength of plastic-based mortar

The reduction in compressive strength (CS) of cementitious composites incorporating waste plastic is the main concern limiting its applicability in the building sector. Using industrial wastes as cement substitutes to enhance the CS of plastic mortar is a sustainable approach. This study used fine powdered waste materials such as silica fume (SF), marble powder (MP), and glass powder (GP) in plastic-based mortar for their effectiveness in enhancing CS. Plastic mortar specimens were cast using plastic waste in 5–25 % contents as sand replacement by mass, and their 28-day CS was recorded as a reference. SF, GP, and MP were utilized in plastic mortar mixtures separately in proportions of 5–25 %, with a 5 % increment, substituting cement by mass. These waste powders were also used in combinations of two (SF+GP, SF+MP, and GP+MP) and three (SF+GP+MP) in plastic mortar mixtures. Moreover, prediction models were built using the experimental database for the CS of plastic mortar. Gradient boosting and bagging ensemble machine learning (ML) techniques were chosen for model development. The decrease in CS was limited by substituting SF, GP, and MP for cement in plastic mortar. It was determined that the most effective substitution levels for SF, GP, and MP in plastic mortar, according to the strength enhancement, were 15, 10, and 15 wt.% of cement, respectively. The ML models closely matched experimental results, and in terms of R2 and error evaluations, bagging model outputs were more accurate than gradient boosting. The gradient boosting and bagging models had R2 of 0.89 and 0.94, respectively, with average absolute errors of 0.87 and 0.65 MPa.

Supercritical Water Liquefaction of Mixed Waste Polystyrene, Polypropylene, and Polyethylene for Production of High Yield Oils.

Supercritical water liquefaction of different plastic wastes has been investigated under high-temperature and high-pressure conditions. The supercritical water liquefaction of commonly used plastic types, comprising polystyrene (PS), polypropylene (PP), and low-density polyethylene (LDPE) as well as their mixtures, is reported. The experiments were carried out at varying feedstock-to-water ratios with a residence time of 60 min under supercritical water reaction conditions. The process produced high oil yields of over 97 wt %, with the highest yields obtained at a plastic:water ratio of 1:3; at higher levels of input water, the yield of oil decreased slightly. The gas phase mainly consisted of light hydrocarbons such as methane, ethane, propane, and butane, with propane found to be the most abundant gas component. Aromatic hydrocarbons and alicyclic hydrocarbons were the major products in the product oil from the supercritical water liquefaction of polystyrene and polypropylene, whereas alkanes were predominant in the oil obtained from LDPE. Analysis of the oil obtained from binary (1:1) and ternary (1:1:1) plastic mixtures showed it exhibited aromatic hydrocarbons as the major constituent, indicating synergistic interaction. It was found that the incorporation of PP in the mixture facilitated the production of cyclic compounds and suppressed the production of alkanes. Supercritical water liquefaction offers an effective solution to plastic pollution, producing valuable products without the need for catalysts.

WASTE PROCESSING BY PLASMA ARC ELECTROLYTIC CENTRIFUGAL CONVERSION

The plasma-arc electrolytic centrifugal conversion process was developed for processing of crude ore materials and hydrocarbons to end products with simultaneous generation of energy carriers and energy [1]. The developed process may be used with a similar purpose for processing of various wastes. Industrial and household wastes have identical chemistry with common ore and hydrocarbons. Waste ore called “tailings” is comparable to payable ore and, just as in base ore, oxygen comprises about half of its composition. Household wastes for the most part contain organic compounds, including plastic, wood, paper, and form hydrocarbon mixtures containing various metals and nonmetals. Melted waste mixture contains almost every elements of the periodic table with various chemical elements acting as reaction catalysts. The wastes are processed under electric energy generated by hydrogen burning in oxygen. Hydrogen is recovered from hydrocarbon materials contained in household wastes and water contained in the feed. Oxygen is recovered from waste ore. Hydrogen and oxygen are stored in a methanol compound obtained from synthesis gas generated in the course of waste plasma melting.

Development of a Biodegradable Cassava Starch Biofilm based on a Combination of Plasticizers with Bio‐SiO2 Extracted from Sugarcane Leaves

AbstractThis study prepares biodegradable biofilms for packaging applications from biomass to help reduce plastic waste while also adding value to biomass. Furthermore, the effects of plasticization with 30 wt% plasticizer (relative to the mass of cassava starch) by glycerol (G), sorbitol (S), and a mixture of glycerol and sorbitol (GS) plasticizers are investigated, and the effects of bio‐SiO2 particles extracted from sugarcane leave via the sol–gel method are evaluated in terms of the mechanical and biodegradability properties of the cassava starch‐based biofilms. Biofilms used for packing applications must be insoluble and exhibit good elongation properties. In this context, the results indicate that the GS mixture produces a biofilm that exhibits these desirable properties. Thus, cassava starch‐based biofilms are prepared using GS and varying concentrations of the bio‐SiO2 particles (i.e., 0, 0.5, 1, and 1.5 wt%). The films containing bio‐SiO2 exhibit significantly lower water solubilities and moisture contents than the corresponding bio‐SiO2‐free films. Additionally, the inclusion of bio‐SiO2 particles increases the water resistance properties of the biofilms. Overall, the results suggest that cassava starch films prepared using a mixture of plasticizers and reinforced with bio‐SiO2 particles can be considered a safe material for application in biodegradable food packaging.

Transformation of biomass and waste plastic mixtures into hydrocarbon oils and gases by pyrolysis using different reactor temperatures and pressures

In this work the laboratory scale pyrolysis and gasification of biomass and plastic waste mixtures were investigated at different temperatures (450°C and 750°C) and reactor pressures (0.1 bar and 1.0 bar). The main decomposition reactions and the effect of the process parameters were followed through the product yields and compositions of gases and pyrolysis oils. Less residue and significantly more gases had been found at higher temperature, which phenomena was more notable in case of higher proportion of plastic waste in the raw material mixtures. The concentration of hydrogen in gases changed by opposite trend at 450°C and 750°C as function of biomass ratios. The hydrogen and CO ratio can also increase by the increasing in plastic proportion of raw materials at both temperatures and pressures. Regarding the pressure, it can increase the pyrolysis and gasification reactions resulted higher yields of gases and lower oil/water ratios. More hydrogen and less C2-C6 compounds were found using 0.1 bar reactor pressure. Pyrolysis-oil contained aliphatic and aromatic hydrocarbons; n-paraffin, n-olefin, aldehyde, ketones, alcohols, phenols, carboxylic acids, etc. Due to deoxygenation reactions, hydrocarbons with less oxygen-containing compounds were found at 0.1 bar pressure.

Oscillation rheology, calorimetry and computed tomography: A practical toolkit combination of qualification for real poly(ethylene terephthalate) waste

The conventional qualification methodologies, such as internal viscosity measurement and Melt Flow Index (MFI) tests, which are routinely applied to pristine materials and homogenous waste, are not directly transferrable to the qualification process of plastic mixtures. The current investigation is oriented towards the development of a pragmatic suite of measurements techniques aimed at facilitating the qualification of diverse real polyethylene terephthalate (PET) waste streams. This is primarily achieved through the integration of oscillatory rheology, calorimetry and computed tomography (CT). Samples derived from both selective income (SI) and sorting residue (SR) of a manual selective waste sorting plant are included, along with an examination of PET material originating from refuse-derived fuel (RDF). To establish references for comparison, manually collected bottles with (BCL) and without (B) caps and labels are employed, leveraging their known composition and purity. Calorimetry reveals that the glass transition temperature (Tg) is the most sensitive parameter for tracking the structural and compositional changes in waste PET-based streams. The utilization of temperature sweep test in rheology for determining the melting temperature (Tm) proves advantageous, offering a significantly shorter measurement time (∼1:24) compared to calorimetry. Importantly, this approach yields the Tm of the genuine composition rather than individual components. Detection of metal content contaminations in PET waste streams is made possible through CT, while frequency tests in rheological measurements demonstrate effectiveness in discerning their effects.

Factors influencing synergistic pyrolysis of biomass and polypropylene for alcohols and hydrocarbon production

Results are presented on the co-pyrolysis of different blends of rapeseed stalk and plastic polypropylene (100:0, 75:25, 50:50, 25:75 and 0:100) using thermogravimetric analysis (TGA), Fourier transform infrared (FTIR) spectroscopy and pyrolyzer-gas chromatography/mass spectrometry (Py-GC/MS), independently. The effect of temperature (450, 550 and 650 °C) on the synergistic effect between rapeseed stalk and polypropylene at different blend ratios as well as on the yield and amounts of alcohols and hydrocarbons produced are presented. The thermogravimetric analysis results showed that at the same temperature, increase of polypropylene in the mixture, gradually increased the intensity and rate of pyrolysis reaction. The weight loss data revealed improved pyrolysis during the process. The Fourier transform infrared spectroscopy results showed that the transmittance of ketones, esters and acids increased while the content of ketones, esters and acids decreased with increased polypropylene in the mixture. The pyrolyzer-gas chromatography/mass spectrometry results showed that temperature and feedstock mixture ratio had an impact on the yield and amounts of alcohols and hydrocarbons. The pyrolysis effect was most favorable at 550 °C temperature and rapeseed stalk/polypropylene mixture ratio of 1:3. These results provide some practical insights on clean energy recovery from mixtures of agricultural residues and waste plastics using thermochemical conversion.

Exploring the Influence of Plastic Powder Incorporation on Geotechnical Properties of Expansive Soil Stabilized with Granite Powder for Building Applications

An experimental study was undertaken to investigate the effect of plastic and granite waste powder on the geotechnical performance of expansive soil, using different mix ratios. The soil studied is Hachem, in the northwestof Algeria. In this context, first reinforcing the plastic powder with granite powder, then add the mixture to the expansive soil. The percentage of plastic powder is (0%, 1%, 2%, 3%, 4%) and reinforced at 2%, 4%, 6% and 8% with granite powder. The experimental results showed a gradual decrease in liquid limits, swell potentials, and swelling pressure as the proportions of plastic and granite powder increase. In terms of the results obtained by reducing swelling and swelling pressure values and increasing unconfined compressive strength (UCS) tests and ductility values, this mixture of waste plastics and granite can be of great importance in improving the mechanical properties of samples.

Investigation of waste LDPE with Pongamia pinnata seed for sustainable resource recovery: Thermodynamics, Kinetics and artificial neural network modeling for co-pyrolysis potential

Pyrolysis conversion offers the advantages of significant waste reduction and potential energy recovery. This work examined the potential of combining plastic and agricultural wastes as pyrolysis feedstocks. The mixture of waste low-density polyethylene and Pongamia pinnata seeds was analysed using differential and thermogravimetric methods. In addition to the Coats-Redfern (CR) method, Kissinger-Akahira-Sunose (KAS), Flynn-Wall-Ozawa (FWO), Friedman (FRM), and Kissinger (KN) model-free methods were also applied to calculate the kinetic parameters. The apparent activation energy (Ea) calculation demonstrated that the co-pyrolysis conversion required Ea values of 125–154 kJ mol−1. The artificial neural network (ANN) model was considered to validate thermogravimetric data. The R2 values were near unity in training, validation, and testing conditions, with the minimum possible value for mean square error obtained for the considered heating rates. The Pongamia pinnata seeds and waste plastic mixture could surely be utilized to lessen environmental degradation, add value to leftover seeds and waste low-density polyethylene by extracting fuel for transportation and other commercial activities, and produce industrial chemicals, as found through the kinetic modelling, thermodynamic parameters, and ANN modelling.

Fast co-pyrolysis of wood and plastic: Evaluation of the primary gaseous products

Bio-oil derived from fast pyrolysis of wood contains oxygenates and has a relatively low heating value. These are challenges that need to be tackled if wood-derived bio-oil is to be used as drop-in fuels. The bio-oil can be obtained by condensation of gaseous products. Using a material with no oxygen in addition to wood during fast pyrolysis could be a technique to reduce the formation of oxygenates and promote a hydrocarbon-rich product. This work aims to evaluate the primary gaseous products formed during fast co-pyrolysis of birch wood and plastic. The pyrolysis was performed in a micropyrolyser at 600 °C with a residence time of 5 s. Birch wood and plastic were melt-mixed at different weight ratios to study possible interaction effects upon pyrolysis. The different plastics used were low-density polyethylene (LDPE), polypropylene (PP) and polystyrene (PS). The total gaseous product was between 10–20 wt% from Wood-LDPE or Wood-PP, while it was in the range 15–90 wt% from Wood-PS. The analysis of gas product found that the formation of oxygenates (up to 9 wt%) was lower than expected (up to 14 wt%) for the mixtures of wood and plastic compared to the pure materials (about 18 wt%). The reduction of oxygenates (up to 90 %) was mainly due to a lower production of ketones, carboxylic acids and aldehydes. Maximum hydrocarbons in the gas phase from binary mixtures were around 8, 15 and 55 wt% from Wood-LDPE, Wood-PP and Wood-PS, respectively. The most significant difference between experimental and estimated values assuming no interaction among hydrocarbons was observed in the case of alkenes and alkanes for Wood-LDPE, as well as alkanes for Wood-PS, while the Wood and PP mixture showed almost no signs of interaction. This work is beneficial for understanding interactions between wood and plastics, and could be used to reduce the amount of oxygenates from wood pyrolysis and reduce the need for upgrading.

The effect of Polyethylene Terephthalate (PET) plastic addition to AC-WC in a wet mixture on increase of asphalt stability

PET (Polyethylene Terephthalate) plastic is one of the most common types of plastic used in Indonesia. Its existence has contributed significantly to various sectors, including the food and beverage, cosmetic, pharmaceutical, and other consumer product packaging industries. However, the use of PET plastic also creates a number of impacts that need to be considered. PET (Polyethylene Terephthalate) plastic has become an attractive alternative in the construction industry in Indonesia, particularly in its use as an asphalt mixture in road construction. This study aimed to determine the effect of the addition of PET waste to the asphalt on the value of Marshall characteristics as well as the optimum asphalt content and plastic content in the AC - WC mixture. Basic testing of 4 %, 5 %, and 6 % (by weight of asphalt) PET plastic mixture with wet mixing method where PET plastic is put into hot asphalt and stirred until homogeneous. Marshall test data will go through Formality Test, Homogeneity Test, Two-Way ANOVA, Duncan Test, and Correlation Regression Analysis to get the 3D graph equation. The result is that PET plastic affects the asphalt mixture by increasing the stability value and MQ value, for flow, VFB, and VMA values have decreased. VIM value increased at 4 % level and decreased at 6 % level. From the ribbon graph, the optimum asphalt content for each percentage of PET content is obtained, namely 4 % PET KAO value of 6.2 %, 5 % PET KAO 6.25 %, and 6 % KAO 6.28 %. It can be concluded that the mixing of PET with asphalt in AC-WC mixtures can be maximum if the right percentage combination of asphalt and PET content. From the 3D Graphic Method, it results that the maximum use of plastic PET is at a content of 5.40 %, and an asphalt content of 6.35 %, will produce an asphalt stability of 1714.232 kN

Influence of Choline Chloride/Urea and Glycerol Plasticizers on the Mechanical Properties of Thermoplastic Starch Plastics.

Bio-based plastics made of food-safe compostable materials, such as thermoplastic starch (TPS), can be designed into films that have potential to replace many non-biodegradable single-use plastic (SUP) items. TPS film characteristics, such as elongation at break and tensile strength, are largely affected by the choice of the plasticizers used in formulation. Our work identifies the mechanical properties and the chemical structural differences between TPS films made with two different plasticizer mixtures that have not yet been compared alongside one another: deep eutectic solvent choline chloride/urea (1:2) (CC:U) and glycerol with an acetic acid catalyst (AA:G). Potato-based TPS samples were formed by mixing each plasticizer with a consistent amount of potato starch and distilled water with heat. After gelation formation, the viscous TPS mixture was centrifuged to degas and extruded. Films were dried at controlled room temperature. Characterization included the tensile testing of coupons according to ASTM (American Society of Testing and Materials) standard D638, attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy, X-ray diffraction (XRD), melting point (MP), and scanning electron microscopy (SEM). The AA:G films displayed significantly higher tensile strength (M = 2.04 ± 1.24 MPa) than the CC:U films (M = 0.18 ± 0.08 MPa); however, the CC:U films had higher elongation at break (M = 47.2 ± 3.6%) than the AA:G films (M = 31.1 ± 12.6%). This can be explained by the difference in functional groups, composition, and the degree of crystallinity evidenced by the FTIR, XRD, MP, and SEM results. Our findings suggest that potato-based TPS films with an AA:G plasticizer mixture hold promise for SUP applications that require more strength, while CC:U films may be more suited for wraps and bags that require flexibility. These innovations can aid to mitigate the environmental impact of harmful plastic waste.

Regulatory Science Perspective on the Analysis of Microplastics and Nanoplastics in Human Food.

Microplastics are increasingly reported, not only in the environment but also in a wide range of food commodities. While studies on microplastics in food abound, the current state of science is limited in its application to regulatory risk assessment by a continued lack of standardized definitions, reference materials, sample collection and preparation procedures, fit-for purpose analytical methods for real-world and environmentally relevant plastic mixtures, and appropriate quality controls. This is particularly the case for nanoplastics. These methodological challenges hinder robust, quantitative exposure assessments of microplastic and nanoplastic mixtures from food consumption. Furthermore, limited toxicological studies on whether microplastics and nanoplastics adversely impact human health are also impeded by methodology challenges. Food safety regulatory agencies must consider both the exposure and the risk of contaminants of emerging concern to ascertain potential harm. Foundational to this effort is access to and application of analytical methods with the capability to quantify and characterize micro- and nanoscale sized polymers in complex food matrices. However, the early stages of method development and application of early stage methods to study the distribution and potential health effects of microplastics and nanoplastics in food have largely been done without consideration of the stringent requirements of methods to inform regulatory activities. We provide regulatory science perspectives on the state of knowledge regarding the occurrence of microplastics and nanoplastics in food and present our general approach for developing, validating, and implementing analytical methods for regulatory purposes.