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Amides often exhibit poor solubility in common solvents, posing challenges to their efficient separation. However, the development of robust RP-HPLC methods becomes essential to overcome this limitation, enabling accurate and reliable separation, quantification and characterization of these compounds. An RP-HPLC–UV technique has been developed for evaluating N,N'-dibutylterephthalamide, N,N'-dimethylterephthalamide, N,N'-bis(2-hydroxyethyl)terephthalamide and terephthalic dihydrazide obtained through aminolytic depolymerization of polyethylene terephthalate waste. The data obtained has been analyzed to arrive at most appropriate values of essential parameters to obtain highly resolved HPLC chromatograms using odyssil C18 column (4.6 × 250 mm, 5 μm) from Agela Technologies with a UV detector. Dimethyl formamide and dimethyl sulfoxide emerged as the most suitable mobile phases with an isocratic run of 10 min at a flow rate of 0.4 mL/minute. Effect of temperature and concentration on HPLC chromatograms was also investigated for N,N'-dibutylterephthalamide from 30 to 50 ℃ and 0.5 mg to 2.5 mg/10 mL of solvent, respectively. 1–2.5 mg/10 mL concentration was found to be most suitable with the column temperature of 40 ℃. Method validation consisted of linearity, intra- and inter-day precision, detection and quantitation limit. The validation experiments confirmed the precision of the present method, with RSD% and CV% values for both intra- and inter-day precision measuring below 1.9% and 0.5%, respectively. The method was linear in the range of 0.5–2.5 mg/10 mL solvent (R2 = 0.98). Detection and quantitation limit were determined to be 1.32 and 4.02 mg/10 mL, respectively, for peak 1 and 0.90 and 2.75 mg/10 mL, respectively, for peak 2. [ABSTRACT FROM AUTHOR]

Thermosetting post-consumer plastics like polyethylene terephthalate (PET) raise serious recycling challenges, leading frequently to disposal through incineration or landfilling. This study assesses the feasibility of cementitious materials containing PET additions including the influence of cement content, water-to-cement ratio (w/c), styrene-butadiene rubber (SBR) polymer additions, and PET volume on the fresh and hardened properties. The mixture proportioning followed the Taguchi methodology, which entailed the utilization of four factors, each possessing three different levels to create an L9 orthogonal matrix. The assessment included diverse performance indicators such as flow, compressive strength, flexural strength, bond strength, water absorption, and resistance to carbonation. Test results revealed that the incorporation of SBR and PET degraded the compressive strength, albeit this can be restored by increasing the cement content and/or reducing w/c. The addition of SBR significantly improved the flexural and bond strengths yet curtailed the water absorption and resistance to carbonation due to increased closed porosity that facilitated the transport properties. The multi-criteria optimization approach (TOPSIS) indicated that superior performance can be achieved using a cement content of 525 kg/m3, w/c of 0.55, SBR of 3.5 %, and PET incorporation of 4.5 %. These parameters were subsequently employed in the development of multivariate regression models, allowing for the prediction of fresh and hardened properties in SBR-PET mortar.

A novel in situ chemical upcycling strategy for plastic waste is proposed by the customized diphenylacetylene monomer with dual photo‐response. That is, diphenylacetylene reactive monomers are in situ inserted into the macromolecular chain of polyethylene terephthalate (PET) plastics/fibers through one‐pot transesterification of slight‐depolymerization and re‐polymerization. On the one hand, the diphenylacetylene group absorbs short‐wave high‐energy UV rays and then releases long‐wave low‐energy harmless fluorescence. On the other hand, the UV‐induced photo‐crosslinking reaction among diphenylacetylene groups produces extended π‐conjugated structure, resulting in a red‐shift (due to decreased HOMO–LUMO separation) in the UV absorption band and locked crosslink points between PET chains. Therefore, with increasing UV exposure time, the upcycled PET plastics exhibit reverse enhanced UV resistance and mechanical strength (superior to original performance), instead of serious UV‐photodegradation and damaged performance. This upcycling strategy at oligomer‐scale not only provides a new idea for traditional plastic recycling, but also solves the common problem of gradual degradation of polymer performance during use. [ABSTRACT FROM AUTHOR]

Plastic pollution has become an environmental issue worldwide because of its slow degradation and persistent nature. Many traditional methods exist and are practiced here to handle and reuse plastic waste, but those need to be more capable of tackling increasing waste volume. Biological plastic waste management could be a sustainable way to ensure environmental quality. Therefore, this study aimed to screen the bio-deterioration of PET wastes using physical and chemical pretreatments. We kept PET samples in freshwater and marine water media designed to support algal growth and incubated those under direct or indirect sunlight or in dark conditions. We observed algal growth and measured deterioration of PET samples using the tensile strength test, FTIR, and viewed surface properties using FESEM. Acid pretreatment and exposure to direct sunlight left the PET most fragile. FTIR analysis also supported the observation, and changes in functional groups are evident. Heat pretreatment usually reduces the volume and thus increases strength. Bottles incubated under direct or indirect sunlight supported the algal growth. The most prevalent algal species found in freshwater environments include Volvox, Chlorella vulgaris, Craticula cuspidate, Navicula pupula, Synedra ulna, and marine environments include Palisada perforate, Ulva flexuosa, Cladoptera herpestica, and Blindingia minima. Algal growth increases the porosity and surface cracks of PET bottles. Though FTIR analysis did not show any change in functional groups, except for acid pretreatment, upon algal growth, the transmittance increase indicated decay of PET samples.

The aim of this study involved the synthesis and characterization of polyurethane (PUR) foams obtained from poly(ethylene terephthalate) (PET) depolymerization products and two types of filling agents, namely fly ash and glass waste. The depolymerized PET-based products were obtained by zinc acetate-catalyzed glycolysis process in diethylene glycol (DEG) as a co-reactant. The resulting glycolysis products were contacted with methylene diphenyl diisocyanate, castor oil, and reinforcing agents. The resulting PUR specimens were characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), EDX mapping, mechanical tests, and thermal analysis. The analysis confirmed that the best mechanical performances were registered by the specimens with the lowest concentration of filling agent, while the highest thermal resistance was achieved by the PUR foams with the highest concentration of reinforcing agent.

Due to the extensive utilization of poly (ethylene terephthalate) (PET), a significant amount of PET waste has been discharged into the environment, endangering both human health and the ecology. As an eco-friendly approach to PET waste treatment, biodegradation is dependent on efficient strains and enzymes. In this study, a screening method was first established using polycaprolactone (PCL) and PET nanoparticles as substrates. A PET-degrading strain YX8 was isolated from the surface of PET waste. Based on the phylogenetic analysis of 16S rRNA and gyrA genes, this strain was identified as Bacillus safensis. Strain YX8 demonstrated the capability to degrade PET nanoparticles, resulting in the production of terephthalic acid (TPA), mono (2-hydroxyethyl) terephthalic acid (MHET), and bis (2-hydroxyethyl) terephthalic acid (BHET). Erosion spots on the PET film were observed after incubation with strain YX8. Furthermore, the extracellular enzymes produced by strain YX8 exhibited the ability to form a clear zone on the PCL plate and to hydrolyze PET nanoparticles to generate TPA, MHET, and BHET. This work developed a method for the isolation of PET-degrading microorganisms and provides new strain resources for PET degradation and for the mining of functional enzymes. [ABSTRACT FROM AUTHOR]

In light of the escalating accumulation of polymer waste in daily life, chemical recycling of polymers and value-added utilization of products have gained considerable attention in recent years. Researchers have widely explored the potential of bis(2-hydroxyethyl) terephthalate (BHET) derived from the glycolysis recycling of poly(ethylene terephthalate) (PET) waste in the synthesis of polymers or concrete. In this study, we synthesized BHET through glycolysis recycling of PET, and combined it with microencapsulated ammonium polyphosphate (SiO2@APP) and carboxymethyl chitosan to design a series of intumescent flame-retardant waterborne polyurethane (IFRWPU). The synergistic effect of BHET and SiO2@APP was demonstrated, and the resulting IFRWPU with 12.5 wt% IFR and 3 wt% BHET achieved a limit oxygen index of 25.8% and a 73% reduction in the peak heat release rate in flame retardancy tests. Furthermore, the interaction of BHET and flame retardant was discussed using the analysis of char residue and pyrolytic gas. Overall, this work provides a novel strategy to construct superior flame-retarded waterborne polyurethane with admirable bonding performance. [ABSTRACT FROM AUTHOR]

Towards global efforts for efficient and sustainable ways to utilize polyethylene terephthalate (PET)‐based plastic waste, herein we report an integrated process for the complete one‐pot transformation of PET‐based plastic waste for hydrogen gas production in an alkaline aqueous condition over a heterogeneous ruthenium catalyst at low temperature (110‐160 °C). We could achieve complete selectivity with a high yield of H2 gas (∼38,000 mL H2/gPET/gRu) without any traces of CO and CO2 contaminations. Complete depolymerization of different types of PET‐based plastic waste was also achieved with high carbon yield (∼98 %) for disodium terephthalate (Na2TPA, 5.2 mmol/gPET) and sodium formate (SF, 9.6 mmol/gPET), along with H2 gas. Moreover, the developed process is scalable to bulk‐level production of hydrogen gas from PET‐based plastic waste, highlighting the potential application of the developed process. [ABSTRACT FROM AUTHOR]

This work provides an overview of the importance of recycling PET waste to reduce the environmental impact of plastic waste, conserve natural resources and energy, and create jobs in the recycling industry. Many countries have implemented regulations and initiatives to promote the recycling of PET waste and reduce plastic pollution, such as extended producer responsibility (EPR) systems, bans on certain single-use plastics, and deposit–return systems for plastic bottles. The article further underscores the versatility of recycled PET, as it can be transformed into various products such as fibers, sheets, film, and strapping. These recycled materials find applications in numerous sectors including clothing, carpets, upholstery, and industrial fibers. Recognizing the importance of collaboration among governments, industries, and individuals, we emphasize the need for sustainable PET waste management practices and the promotion of recycled materials. The article also provides information on India's experiences with PET waste management and regulations in other countries. It is important to note that the global production and consumption of PET have increased significantly in recent years, with the packaging industry being the largest consumer of PET. This has resulted in a significant increase in the generation of PET waste, which poses a significant environmental and health hazard if not managed properly. PET waste can end up in landfills, where it can take hundreds of years to decompose, or it can end up in the oceans, where it can harm marine life and the environment. Therefore, the proper management and recycling of PET waste are essential to mitigate these negative impacts. In terms of India's experiences with PET waste management, several initiatives have been implemented to promote the recycling of PET waste. For example, the government has launched the Swachh Bharat Abhiyan campaign, which aims to promote cleanliness and sanitation in the country to promote waste segregation and recycling. [ABSTRACT FROM AUTHOR]

Plastic waste is one of the major challenges facing modern society. Against the background of climate change and finite fossil resources, the realization of a true circular economy for plastics is imperative. Mechanical recycling processes offer a short‐cut path for the recycling of clean, single material waste while they are not capable to handle mixed material or colored feeds. Complementary technologies are necessary to recover pure monomers, hydrocarbon mixtures or syngas from mixed secondary raw material to continuously close the loop in a circular plastics economy. Using the example of PET, this contribution discusses the benefit of integrating a back‐to‐monomer recycling for closing the loop aiming at a holistically approach integrating technological, ecological and economic aspects. [ABSTRACT FROM AUTHOR]

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 440 nm, 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 2.0 nm, 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 250–450 nm light with excellent properties, and its transparency for 450–700 nm 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 395 nm LED chips is (0.55, 0.44) and the correlated color temperature is 2018 K. [ABSTRACT FROM AUTHOR]

In this polymer-governing era, polyethylene terephthalate (PET) has become one of the most demanding consumables. This growing interest in the production and consumption of plastic products results in an increase in the volume of post-consumer plastic waste. However, due to the growing concern for environmental protection, recycling PET waste to the valuable ones has become one of the hot topics in contemporary research. In this study, PET waste was depolymerized using ethanolamine as a depolymerizing agent. N,N0-Bis (2-hydroxyethyl)terephthaldiamide (BHETA) (yield 77%) was obtained after depolymerization of PET via ethanolamine. The characterization of the monomer BHETA was done using FTIR, 1H NMR, and FE-SEM. The thermal stability of PET and BHETA was done using TGA analysis. To avoid the extreme reaction condition (high temperature and high pressure) of conventional way to form terephthalic acid (TPA) via hydrolysis of PET waste, in this study, a facile way is performed. The monomer BHETA was converted to a main building block of PET (TPA) (yield 67%) using strong oxidizing agent KMnO4 in mild reaction conditions at room temperature and pressure. The synthesized TPA was characterized using FTIR and 1H NMR. This work also focuses on the anticipation of the reaction progress of aminolysis of PET using simple analytical tools namely, FTIR and TGA. [ABSTRACT FROM AUTHOR]

The poly(ethylene terephthalate) is a thermoplastic polyester, non-degradable in the environment that due to the huge amount of waste generated and accumulated in landfills, chemical recycling through glycolysis is considered the most successful method for polymer recycling. In this work, glycolysis of virgin PET and different PET waste (highly coloured PET, multilayer PET and municipal sorting waste PET) is carried out using excess ethylene glycol in the presence of zinc acetate as catalyst. Glycolysis temperature, glycolysis time, amount of catalyst and amount of solvent are important factors affecting the glycolysis of PET waste. A Taguchi orthogonal array L9, 34, is applied to study the main interactions between these factors to optimise the yield. The process results in a good yield (79–88%) to the monomer, bis(2-hydroxyethyl) terephthalate (BHET), with optimum conditions. One of the inconvenient of the glycolysis process is the excessive use of EG, so the recovery and reuse of the remaining EG from the process are studied in order to optimise the glycolysis of PET waste making it economical and environmentally friendly. BHET is characterised by FTIR and DSC techniques confirming that is a valid and pure monomer. [ABSTRACT FROM AUTHOR]

The use of polyethylene terephthalate (PET) has extensively turned into an environmental global issue that requires multiple approaches to give use or recycle this material. This investigation analyzes the incorporation of PET laminates from post-consumer two-liter soda plastic bottles in combination with a fique fabric as a natural fiber reinforcement and an epoxy resin as the matrix. The value of this composite is the combination of a solid waste material with natural fibers, as a strategy to reduce plastic pollution in high-performance applications. The developed composite is aimed to be used in structural and impact applications. The mechanical properties were evaluated via Charpy and flexural tests, while the microstructure of the composite was investigated by scanning electron microscopy. From the structural point of view, the sandwich-structure composite proved to be a strong material, while amazingly the energy absorbed in an epoxy-PET-fique composite formulation was found to be better under impact when compared to the neat resin and to the epoxy-fique composite.

Glycolysis of post-consumer polyethylene terephthalate (PET) waste is a promising chemical recycling technique, back to the monomer, bis(2-hydroxyethyl) terephthalate (BHET). This work presents sodium methoxide (MeONa) as a low-cost catalyst for this purpose. BHET product was confirmed by gas chromatography-mass spectrometry (GCMS), Nuclear Magnetic Resonance (NMR) Spectroscopy, melting point, and Differential Scanning Calorimetry (DSC). It was shown, not surprisingly, that PET conversion increases with the glycolysis temperature. At a fixed temperature of 190 °C, the response surface methodology (RSM) based on the Box-Behnken design was applied. Four independent factors, namely the molar ratio of PET: MeONa (50–150), the molar ratio of ethylene glycol to PET (EG: PET) (3–7), the reaction time (2–6 h), and the particle size (0.25–1 mm) were studied. Based on the experimental results, regression models as a function of significant process factors were obtained and evaluated by analysis of variance (ANOVA), to predict the depolymerization performance of MeONa in terms of PET conversion. Coefficient of determination, R2 of 95% indicated the adequacy for predicted model. Afterward, the regression model was validated and optimized within the design space with a prediction of 87% PET conversion at the optimum conditions demonstrating a deviation of less than 5% from predicted response. A van 't Hoff plot confirmed the endothermic nature of the depolymerization reaction. The ceiling temperature (TC = 160 °C) was calculated from Gibbs' free energy. A kinetic study for the depolymerization reaction was performed and the activation energy for MeONa was estimated from the Arrhenius plot (EA = 130 kJ/mol). The catalytic depolymerization efficiency of MeONa was compared under similar conditions with widely studied zinc acetate and cobalt acetate. This study shows that MeONa's performance, as a glycolysis catalyst is promising; in addition, it is much cheaper and environmentally more benign than heavy metal salts. These findings make a valuable contribution towards the chemical recycling of post-consumer PET waste to meet future recycling demands of a circular economy. [ABSTRACT FROM AUTHOR]

Sulfur and nitrogen-doped carbon dots (SN-CDs) were prepared by the solvothermal method with PET waste, sulfuric acid, and phenylenediamine as precursors. The as-prepared SN-CDs were characterized by TEM, XPS, FTIR, NMR, and fluorescence spectrometer, and their applications in light-blocking membranes (LBFs) were explored. The results show that SN-CDs are spherical structures with an average particle size of 4.3 nm, and there are sulfur-containing and nitrogen-containing groups on their surface. The fluorescence emission peak for SN-CDs is dependent on the excitation wavelength in the range from 320 to 500 nm. When the excitation wavelength is 420 nm, the emission peak for SN-CDs is located at 540 nm, and the fluorescence intensity is the highest. The fluorescence quantum yield can reach 49.36%, and the average fluorescence lifetime is 6.28 ns. In terms of application, the as-prepared SN-CDs could be dispersed in polylactic acid (PLA) matrix to prepare light-blocking film (LBFs) for UV and blue light. When the amount of SN-CDs is 7%, the blocking rate of LBFs for 365 nm ultraviolet light is close to 100%, and the blocking rate for 430 nm blue light is as high as 90%. As a result, its ability to block light from mobile phone screens and the sun is better than that of commercially available glasses, and its ability to block light from mobile phone screens and the sun is excellent. [ABSTRACT FROM AUTHOR]

In this study, an innovative low-cost carbon powder that is obtained by pοlyethylene terephthalate (PET) bοttles waste was investigated for the removal of Pb (II) ions from aqueous solution. For this, carbon sample was characterised by a liquid displacement method, point of zero charge pH (pHPZC), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). In addition to this, batch experiments were carried out to study the effect of the main parameters such as contact time, initial Pb (II) concentration, adsorbent dosage and pH of the medium on the adsorption process. As results, the maximum adsorption capacity reached 97.95 mg.g−1 with an initial Pb (II) concentration of 100 mg.L−1, pH = 6.0, sorbent concentration of 0.4 g.L−1, agitation speed of 360 rpm, and temperature of 20°C. Dynamic studies using the solver add-in with Microsoft Excel showed that the adsorption of Pb (II) is well described by a pseudo-second-order kinetic model, while its equilibrium isotherm analysed by Langmuir, Freundlich, Redlich–Peterson and Sips models confirmed that the Langmuir isotherm model is in good agreement with the experimental data of the process. From environmental and economic view, the results of the present study show that PET waste is advantageous and an effective adsorbent for the elimination of lead from aqueous solutions. [ABSTRACT FROM AUTHOR]

The use of polyethylene terephthalate (PET) has extensively turned into an environmental global issue that requires multiple approaches to give use or recycle this material. This investigation analyzes the incorporation of PET laminates from post-consumer two-liter soda plastic bottles in combination with a fique fabric as a natural fiber reinforcement and an epoxy resin as the matrix. The value of this composite is the combination of a solid waste material with natural fibers, as a strategy to reduce plastic pollution in high-performance applications. The developed composite is aimed to be used in structural and impact applications. The mechanical properties were evaluated via Charpy and flexural tests, while the microstructure of the composite was investigated by scanning electron microscopy. From the structural point of view, the sandwich-structure composite proved to be a strong material, while amazingly the energy absorbed in an epoxy-PET-fique composite formulation was found to be better under impact when compared to the neat resin and to the epoxy-fique composite. [ABSTRACT FROM AUTHOR]

The circular economy is a path that society, governments, and business must adopt to develop a viable and sustainable model for plastic production. Following the route guided by the United Nations and the new laws of the European Union, such as the Green Deal, it will be able to put an end to the great problem of this era, the inadequate treatment and management of plastic waste. On the plastics production ladder, poly(ethylene terephthalate) (PET) ranks fifth alongside polyurethanes, but only an average of 17% of total PET waste is recycled. Moreover, according to the latest survey made by Zero Waste Europe, most of this recycling source is used in low features applications through a downcycling process. There are mainly two ways for PET recycling, it can be done mechanically or chemically. On the one hand, mechanical recycling is easy to employ but presents some limitations as the properties of the final product decrease from the second cycle, whereas chemical recycling offers versatile procedures although it requires huge amounts of investment money. To address these drawbacks, diverse chemical recycling methods, specially aminolysis and glycolysis, were proposed as the promising way to obtain high added‐value products. In this review, different updated state of the art works about recycling of PET were discussed, presenting the two forms for recycling PET waste, mechanical and chemical approach, and the reason of why is important to focus on the obtention of high‐added value products in an upcycling process. [ABSTRACT FROM AUTHOR]

Due to the extensive utilization of poly (ethylene terephthalate) (PET), a significant amount of PET waste has been discharged into the environment, endangering both human health and the ecology. As an eco-friendly approach to PET waste treatment, biodegradation is dependent on efficient strains and enzymes. In this study, a screening method was first established using polycaprolactone (PCL) and PET nanoparticles as substrates. A PET-degrading strain YX8 was isolated from the surface of PET waste. Based on the phylogenetic analysis of 16S rRNA and gyrA genes, this strain was identified as Bacillus safensis. Strain YX8 demonstrated the capability to degrade PET nanoparticles, resulting in the production of terephthalic acid (TPA), mono (2-hydroxyethyl) terephthalic acid (MHET), and bis (2-hydroxyethyl) terephthalic acid (BHET). Erosion spots on the PET film were observed after incubation with strain YX8. Furthermore, the extracellular enzymes produced by strain YX8 exhibited the ability to form a clear zone on the PCL plate and to hydrolyze PET nanoparticles to generate TPA, MHET, and BHET. This work developed a method for the isolation of PET-degrading microorganisms and provides new strain resources for PET degradation and for the mining of functional enzymes.

"Green" thermally stable hardener was synthesized from a PET waste. The rigid molecular linear structure of the new hardener suggests that it will provide the polymer matrix with the necessary physical and mechanical characteristics. It also allows the expectation that cured matrix based on this hardener can provide increased toughness. New hardener was used as a curing agent for three epoxy resins—tetraglycidyl methylenedianiline (TGDMA, 111–117 EEW), diglycidylether of bisphenol A (DGEBA, 170-192 EEW) and solid epoxy resin (SER)—with a medium molecular weight (860–930 EEW) based on DGEBA. The mixtures were found to have the highest Tg for the DGEBA resin, and high of that for TGDMA and SER. According to the DMA analysis for two cured matrices, the hardener proved to be no worse than the standard ones, and made it possible to obtain cured matrices with excellent mechanical properties, which allows us to hope for further application of new hardener cured epoxy matrices in appropriate composite materials at high temperatures. [ABSTRACT FROM AUTHOR]

Poly(ethylene terephthalate) (PET) is one of the most consumed polymers because of its excellent thermal and mechanical properties. By increasing in PET production and since the disposal of PET waste has grown to be a major global environmental issue each year. Chemical recycling is the most successful method to achieve circular economy in the PET utilizing industries. Current research work aims to complete depolymerization of waste PET from soft drink bottles by the aminolysis method to produce bis (2-hydroxy ethylene) terephthalamide (BHETA) in the presence of Sn doped ZnO. To evaluate catalytic activity, Sn(II) doped ZnO nanoparticles prepared using different Sn(II) molar ratios at 0.5, 1.0 and 2.0 mol% and calcined at 500 °C for 1 h. The synthesized catalysts characterised using FT-IR, XRD, and UV–vis spectroscopy. The surface morphology and percentage doping obtained from SEM and SEM–EDS, respectively. We have observed a reduction in optical band gap and crystallite size of ZnO due to tin doping. Aminolytic depolymerization of PET waste using ethanolamine was promoted by Sn doped ZnO effectively under conventional thermal method. Increase in the yield of the BHETA observed with respect to increased doping percentage of Sn, and 1, 2 mol% Sn doped ZnO nanoparticles afforded over 90% of BHETA. Structure and purity of BHETA, depolymerised product was characterized by FT-IR, 1HNMR, 13C NMR, and MS. [ABSTRACT FROM AUTHOR]

Polyethylene terephthalate (PET) waste presents a significant environmental challenge due to its durability and resistance to degradation. Innovative approaches for upcycling PET waste into high-value chemicals can mitigate these issues while contributing to a circular economy. In this study, we developed a multi-enzyme cascade system in E. coli to convert PET-derived monomer terephthalic acid (TPA) into vanillin (VAN). The metabolic engineering approach was then employed to increase VAN production, including 1) inhibition of VAN degradation by knocking out endogenous aldehyde reductases and alcohol dehydrogenases and 2) enhancement of TPA uptake by modifying membrane proteins to increase cell permeability. The engineered E. coli demonstrated a VAN production of 658.55 mg/L from 1992 mg/L of TPA with a molar conversion rate of 71.1 %, representing the highest production of VAN using TPA as the substrate. Additionally, the engineered E. coli effectively converted post-consumer PET waste into VAN under mild conditions, with the highest production of 259.2 mg/L in 20× diluted PET hydrolysates, highlighting its potential for application in PET waste upcycling. This approach not only provides an environmentally friendly alternative to traditional chemical synthesis but also offers substantial economic benefits by transforming low-value waste into high-value chemicals., (Copyright © 2024. Published by Elsevier B.V.)

Over 30 million ton of poly(ethylene terephthalate) (PET) is produced each year and no more than 60% of all PET bottles are reclaimed for recycling due to material property deteriorations during the mechanical recycling process. Herein, a sustainable approach is proposed to produce redox-active nanoparticles via the chemical upcycling of poly(ethylene terephthalate) (PET) waste for application in energy storage. Redox-active nanoparticles of sizes lower than 100 nm were prepared by emulsion polymerization of a methacrylic-terephthalate monomer obtained by a simple methacrylate functionalization of the depolymerization product of PET (i.e., bis-hydroxy(2-ethyl) terephthalate, BHET). The initial cyclic voltammetry results of the depolymerization product of PET used as a model compound show a reversible redox process, when using a 0.1 M tetrabutylammonium hexafluorophosphate/dimethyl sulfoxide electrolyte system, with a standard redox potential of −2.12 V vs. Fc/Fc+. Finally, the cycling performance of terephthalate nanoparticles was investigated using a 0.1 M TBAPF6 solution in acetonitrile as electrolyte in a three-electrode cell. The terephthalate anode electrode displays good cycling stability and performance at high C-rate (i.e., ≥5C), delivering a stable specific discharge capacity of 32.8 mAh.g−1 at a C-rate of 30 C, with a capacity retention of 94% after 100 cycles. However, a large hysteresis between the specific discharge and charge capacities and capacity fading are observed at lower C-rate (i.e., ≤2C), suggesting some irreversibility of redox reactions associated with the terephthalate moiety, in particular related to the oxidation process.

The use of disposable containers and packaging materials has increased due to the recent COVID-19 pandemic. Thus, the generation of plastic waste is also increasing, and research on recycling such waste is being actively conducted. In this study, an X-ray-shielding film for medical diagnosis was manufactured by mixing a radiation-shielding material and a plastic waste-based polymer material and its effectiveness was evaluated. The film, which is intended as a fabric for a shielding garment, consists of barium sulfate (BaSO4) shielding nanoparticles embedded in a matrix of polyethylene terephthalate (PET), a commonly available waste plastic material. A particle-dispersing technology, which can improve the ratio between the shielding and matrix materials while maintaining the tensile strength of the film, was studied. Therefore, to increase the content of the barium sulfate (BaSO4) nanoparticles used as the shielding material, this multi-carrier method—under which the particles are dispersed in units of time—was developed to improve the shielding performance. Compared with the effectiveness of lead (Pb) shielding film, the 3 mm barium sulfate film developed in this study satisfies the lead equivalent of 0.150 mmPb when stacked in two layers. Therefore, a shielding film was successfully manufactured by using plastic waste as a polymer resin and barium sulfate, an eco-friendly radiation-shielding material, instead of lead. [ABSTRACT FROM AUTHOR]

This study examined the suitability of polyethylene terephtal (PET) waste to provide an alternative modification to bitumen and reduce waste accumulation. The chemical structure and physical properties were evaluated for modified bitumen with different PET flakes content from 2 to 10 %. The effect of PET waste content on bituminous systems was analyzed using IR and 1H NMR spectroscopy, differential thermal (DTA) and thermogravimetric (TGA) analyses. The study of change in the microstructure as a result of bitumen modification was carried out using atomic force microscopy (AFM). Regularities of changes in the structural-group composition of bituminous binders after their modification with PET waste have been established. It is noted that the chemical interaction of the base bitumen with PET flakes occurs due to the formation of associative bonds between the oxygen-containing components of the modifier and bitumen. The influence of the modifier on the physical and mechanical properties was evaluated using standard methods (penetration, extensibility and softening point). Based on the physical and mechanical properties of bitumen, such as needle penetration depth (penetration), ductility and softening point, it was found that the optimal dosage of PET waste in terms of asphalt binder characteristics is 3 %. It has been established that PET waste and original bitumen interact both at the chemical and physical levels and can be considered as a suitable alternative for changing the properties of bituminous binders. Thus, the obtained samples of modified bituminous binders have improved physical and mechanical properties, which makes it possible to produce high-strength asphalt concrete pavements based on them. [ABSTRACT FROM AUTHOR]

Background and Situation Analysis: Baltimore County waterways are impaired by pollution from pet waste. Baltimore County engaged in a campaign to reduce bacteria in waterways caused by dog waste. This paper explores modalities to effectuate change in pet owner behavior which will ameliorate the negative effects of dog waste on the environment. Priority Audience: Dog owners living within Baltimore County who are not picking up dog waste in their backyards. Behavioral Objective: The behavioral objective was to encourage people who were not currently picking up dog waste in their yards to start doing so. Strategy/Intervention Planning and Development: The study examined the effectiveness of using a community-based social marketing (CBSM) campaign to reduce bacteria in streams by encouraging dog owners to clean up properly after their pets. Our approach included all elements of the four Ps of marketing (product, price, place, promotion). The study included formative research to understand barriers and motivators of the audience and to test messages. The campaign was implemented in four targeted areas and then bacteria in waterways was measured to evaluate behavior change. Community-based social marketing strategies included interpersonal communication, securing commitments, promoting social norms, using prompts and increasing knowledge of pet waste pollution in waterways. Evaluation Methods and Results: The pilot compared three different delivery methods: (A) direct to household (HH) using door-to-door outreach, (B) outreach at pet-related location(s) and (C) a combination of (A) and (B) in order to determine the best use of resources for future campaigns. Results from four implementation areas were compared to two non-treatment control areas; over 12,000 HHs combined. We measured the effect of the campaign by analyzing the change in the Most Probable Number (MPN) of fecal indicator bacteria (E. coli) per 100 mL of stream water in both implementation and control areas before the campaign as compared to post-campaign. We then compared results from our campaign to any changes that may have also occurred in those same time periods in 2018 (the year prior to our campaign). Comparing 2019 changes to any changes in 2018 helped to determine whether variations in measured bacteria may have been due to seasonal fluctuations. Results showed a measured decrease in bacteria levels in 3 out of 4 targeted areas from pre-implementation to post-implementation. Our research findings suggested that CBSM contributed to decreased bacteria levels in streams. Recommendations for Social Marketing Practice: During this study, we learned the importance of interpersonal communication and partnerships to help promote the product. Partnerships included places where our primary audience trusted information received and places where we could reach a high concentration of our target audience. Results indicate that interpersonal communication at partner locations seemed just as effective as door-to-door outreach. A recommendation for future efforts is that human resources needed for CBSM can be concentrated in partner locations. Door-to-door efforts are still valuable and can be reserved for hot spot areas and potentially supported by volunteers. [ABSTRACT FROM AUTHOR]

Continuously growing adoption of electronic devices in energy storage, human health and environmental monitoring systems increases demand for cost-effective, lightweight, comfortable, and highly efficient functional structures. In this regard, the recycling and reuse of polyethylene terephthalate (PET) waste in the aforementioned fields due to its excellent mechanical properties and chemical resistance is an effective solution to reduce plastic waste. Herein, we review recent advances in synthesis procedures and research studies on the integration of PET into energy storage (Li-ion batteries) and the detection of gaseous and biological species. The operating principles of such systems are described and the role of recycled PET for various types of architectures is discussed. Modifying the composition, crystallinity, surface porosity, and polar surface functional groups of PET are important factors for tuning its features as the active or substrate material in biological and gas sensors. The findings indicate that conceptually new pathways to the study are opened up for the effective application of recycled PET in the design of Li-ion batteries, as well as biochemical and catalytic detection systems. The current challenges in these fields are also presented with perspectives on the opportunities that may enable a circular economy in PET use. [Display omitted] • Use of PET waste in Li-ion batteries, biosensors and gas sensors is reviewed. • The potential of PET waste in green energy storage devices is outlined. • The tuneable features of recycled PET are crucial to develop bio and gas sensors. [ABSTRACT FROM AUTHOR]

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Decomposition of used poly(ethylene terephthalate) (PET) bottles was accomplished by methanolytic degradation using bamboo leaf ash (BLA) as a green and highly efficient heterogeneous catalytic system. The reaction at 200 °C in an autoclave reactor gave dimethyl terephthalate (DMT) and ethylene glycol (EG) in 78% and 76% yields, respectively. The chemical and physical characteristics of the prepared catalyst were studied using X-ray fluorescence (XRF), Fourier-transform infrared spectroscopy (FTIR), X-ray diffractograms (XRD), Energy dispersive X-ray spectrometry (EDX), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Thermal Gravimetric Analysis (TGA) and Brunauer–Emmett–Teller (BET) analyses. The conversion of PET to DMT and EG was completed within 2 h, and the crude as well as the recrystallized products were characterized using HPLC, NMR and IR. The catalyst, owing to its excellent thermal stability, mesoporous nature, bio-compatibility, cost free, easy preparation, recyclability and efficacy make it an attractive alternative and greener solid catalyst for PET depolymerization. [ABSTRACT FROM AUTHOR]

Numerous studies investigated the possibility of incorporating plastic wastes in concrete mixtures, thus contributing to efficient management and sustainable development of the construction industry. This paper investigates the possibility of reducing the water-to-cement ratio and/or incorporating steel fibers or polymeric latexes to mitigate the drop in structural properties of reinforced concrete (RC) beams containing polyethylene terephthalate (PET) additions. The PET was derived from waste plastic bottles that were shredded into small pieces and added during concrete batching at 1.5% to 4.5%, by total volume. Test results showed that the concrete plain and structural properties degrade with PET additions, given their lightweight nature and poor characteristic strength compared to aggregate particles. The reduction of w/c from 0.55 to 0.46 proved efficient to refine the matrix porosity and reinstate the shear and flexural strengths of RC beams. Moreso, the incorporation of 0.8% steel fibers (by volume) or 15% styrene-butadiene rubber latexes (by mixing water) were efficient to enhance the bridging phenomenon and reduce the propagation of cracks during beam testing. [ABSTRACT FROM AUTHOR]

The level of generated plastic waste has awash over a billion metric tonnes of this waste into our Abstract environment. If an effective long-lasting solution to this impending disaster is not provided through recycling, reengineering, and conversion of this waste to resourceful materials. Then sustainability and conservation of natural non-replenishable materials will be severely threatened. The aims to avert the impending consequences of this disaster and conserve natural materials have given rise to a sustainable future in the production of low carbon embedded construction materials. Under these circumstances, this study, therefore, presents the strengths and durability of waste plastic bricks (WPB) produced from blending scrap PET plastics and foundry sand. The WPB masonry bricks were produced using ratios of 10:90, 20: 80, and 30: 70 to the combined dry mass of PET and sand. Series of compressive strength tests, modulus of rupture (MOR) tests, apparent porosity tests, water absorption tests, salt-resistance tests, ultrasonic pulse velocity, and scanning electron microscopy (SEM) tests were conducted to investigate the strength and durability of the WPB in conformance with the South African National Standard (SANS 227) for individual load-bearing masonry face brick unit. Compared to the clay bricks with 18 MPa what of strength, the test result revealed that the WPB rendered an average compressive strength of 35.2 MPa. Furthermore, the test result showed that the WPB recorded significant strength resistance under tension compared to the clay brick due to the ductility properties of scrap plastic waste. Also, the acid effects were significantly resisted on the surface WPBs due to the hydrophobic property of the PET-waste. The stiffness of the clay bricks portrayed brittle response, whereas WPBs benefited with high ductility properties, therefore, revealed a great proportionality between the dynamic modulus and ultrasonic pulse velocity (UPV) with a coefficient of determination (R2) of 90%. [ABSTRACT FROM AUTHOR]

Over 30 million ton of poly(ethylene terephthalate) (PET) is produced each year and no more than 60% of all PET bottles are reclaimed for recycling due to material property deteriorations during the mechanical recycling process. Herein, a sustainable approach is proposed to produce redox-active nanoparticles via the chemical upcycling of poly(ethylene terephthalate) (PET) waste for application in energy storage. Redox-active nanoparticles of sizes lower than 100 nm were prepared by emulsion polymerization of a methacrylic-terephthalate monomer obtained by a simple methacrylate functionalization of the depolymerization product of PET (i.e., bis-hydroxy(2-ethyl) terephthalate, BHET). The initial cyclic voltammetry results of the depolymerization product of PET used as a model compound show a reversible redox process, when using a 0.1Mtetrabutylammonium hexafluorophosphate/dimethyl sulfoxide electrolyte system, with a standard redox potential of -2.12 V vs. Fc/Fc+. Finally, the cycling performance of terephthalate nanoparticles was investigated using a 0.1 M TBAPF6 solution in acetonitrile as electrolyte in a three-electrode cell. The terephthalate anode electrode displays good cycling stability and performance at high C-rate (i.e., ≥5C), delivering a stable specific discharge capacity of 32.8 mAh.g-1 at a C-rate of 30 C, with a capacity retention of 94% after 100 cycles. However, a large hysteresis between the specific discharge and charge capacities and capacity fading are observed at lower C-rate (i.e., ≤2C), suggesting some irreversibility of redox reactions associated with the terephthalate moiety, in particular related to the oxidation process. [ABSTRACT FROM AUTHOR]

Glycolysis of post-consumer polyethylene terephthalate (PET) waste is a promising chemical recycling technique, back to the monomer, bis(2-hydroxyethyl) terephthalate (BHET). This work presents sodium methoxide (MeONa) as a low-cost catalyst for this purpose. BHET product was confirmed by gas chromatography-mass spectrometry (GCMS), Nuclear Magnetic Resonance (NMR) Spectroscopy, melting point, and Differential Scanning Calorimetry (DSC). It was shown, not surprisingly, that PET conversion increases with the glycolysis temperature. At a fixed temperature of 190 °C, the response surface methodology (RSM) based on the Box-Behnken design was applied. Four independent factors, namely the molar ratio of PET: MeONa (50–150), the molar ratio of ethylene glycol to PET (EG: PET) (3–7), the reaction time (2–6 h), and the particle size (0.25–1 mm) were studied. Based on the experimental results, regression models as a function of significant process factors were obtained and evaluated by analysis of variance (ANOVA), to predict the depolymerization performance of MeONa in terms of PET conversion. Coefficient of determination, R2 of 95% indicated the adequacy for predicted model. Afterward, the regression model was validated and optimized within the design space with a prediction of 87% PET conversion at the optimum conditions demonstrating a deviation of less than 5% from predicted response. A van ‘t Hoff plot confirmed the endothermic nature of the depolymerization reaction. The ceiling temperature (TC = 160 °C) was calculated from Gibbs’ free energy. A kinetic study for the depolymerization reaction was performed and the activation energy for MeONa was estimated from the Arrhenius plot (EA = 130 kJ/mol). The catalytic depolymerization efficiency of MeONa was compared under similar conditions with widely studied zinc acetate and cobalt acetate. This study shows that MeONa’s performance, as a glycolysis catalyst is promising; in addition, it is much cheaper and environmentally more benign than heavy metal salts. These findings make a valuable contribution towards the chemical recycling of post-consumer PET waste to meet future recycling demands of a circular economy.

“Green” thermally stable hardener was synthesized from a PET waste. The rigid molecular linear structure of the new hardener suggests that it will provide the polymer matrix with the necessary physical and mechanical characteristics. It also allows the expectation that cured matrix based on this hardener can provide increased toughness. New hardener was used as a curing agent for three epoxy resins—tetraglycidyl methylenedianiline (TGDMA, 111–117 EEW), diglycidylether of bisphenol A (DGEBA, 170-192 EEW) and solid epoxy resin (SER)—with a medium molecular weight (860–930 EEW) based on DGEBA. The mixtures were found to have the highest Tg for the DGEBA resin, and high of that for TGDMA and SER. According to the DMA analysis for two cured matrices, the hardener proved to be no worse than the standard ones, and made it possible to obtain cured matrices with excellent mechanical properties, which allows us to hope for further application of new hardener cured epoxy matrices in appropriate composite materials at high temperatures.

Anthropogenic effects on the aquatic environment are ever present and ever increasing and while a plethora of aquatic contaminants are known to affect fishes, one ubiquitous and increasingly prevalent world‐wide urban runoff pollutant is frequently disregarded, and that is pet waste. While dog waste has been identified as a significant factor contributing to bacteria and nutrient loading within receiving waters and the associated water quality changes are known to affect fishes, the impact of uncollected dog faeces on urban fish populations has never been directly investigated. In this study we exposed creek chub (Semotilus atromaculatus), a widespread tolerant stream minnow, to various realistic concentrations of dog waste as simulated urban park runoff testing both fresh and dried dog faeces in both stagnant and aerated water for 96 h to investigate the impact on fish survival and behaviour. Creek chub percentage mortality increased significantly relative to controls and across an exposure gradient and was likely caused by anoxic conditions. Survivors were initially smaller while those that died were initially larger and presented with abnormal abdominal subdermal lesions post‐exposure. Additional indicators of physiological stress included significantly increased rates of aquatic surface respiration and changes in flume test derived swimming motivation metrics with increased exposure concentrations. Both mortality and behavioural responses were alleviated by aeration. Furthermore, trials with fresh and dried faeces differed only in time‐to‐death and swimming metrics where results from dried trials were similar to those from aerated experiments. Results demonstrated the impact that the global dog waste management problem can have on aquatic communities with effects on creek chub likely to be more severe for less pollution‐tolerant species and also likely to be exacerbated under future scenarios that consider climate change and increased urbanization. [ABSTRACT FROM AUTHOR]

The massive amount of plastic production inevitably leads to huge levels of pollution and, consequently, is threatening the environment and people's safety. To reduce plastic pollution, research on new ways of reutilization of plastic waste is an open issue nowadays. The main purpose of this work is to evaluate the feasibility of the incorporation of ground polyethylene terephthalate (PET) waste in mortars by comparing the values obtained of mechanical resistance (after 28 days), capillarity water absorption coefficients and thermal conductivity coefficients in an experimental program with the standard values. Mortars prototypes produced at ratios of 1:4 and 1:3 in weight, with partial replacement of the aggregate by PET residuals in different percentages (0, 5 and 10%) were considered. The obtained results show a decrease in mechanical resistance of mortars which was inversely proportional to the use of PET residues in the mixture. An increase in resistance of water absorption by capillary action and a decrease in thermal conductivity was also identified. These results indicate that the replacement of natural aggregates by PET residues in mortars is an interesting option to be considered for the production of a new and environmentally friendly material. [ABSTRACT FROM AUTHOR]

Numerous studies investigated the possibility of incorporating plastic wastes in concrete mixtures, thus contributing to efficient management and sustainable development of the construction industry. This paper investigates the possibility of reducing the water-to-cement ratio and/or incorporating steel fibers or polymeric latexes to mitigate the drop in structural properties of reinforced concrete (RC) beams containing polyethylene terephthalate (PET) additions. The PET was derived from waste plastic bottles that were shredded into small pieces and added during concrete batching at 1.5% to 4.5%, by total volume. Test results showed that the concrete plain and structural properties degrade with PET additions, given their lightweight nature and poor characteristic strength compared to aggregate particles. The reduction of w/c from 0.55 to 0.46 proved efficient to refine the matrix porosity and reinstate the shear and flexural strengths of RC beams. Moreso, the incorporation of 0.8% steel fibers (by volume) or 15% styrene-butadiene rubber latexes (by mixing water) were efficient to enhance the bridging phenomenon and reduce the propagation of cracks during beam testing.

Two amide resins, (bis-(2-hydroxy ethylene) terephthalamide) BHETA, and N1,N1,N4,N4 -tetra -(2-hydroxyethyl)-terephthalamide) THETA were prepared from reaction of waste water bottles (PET) with Monoethanolamine (MEA) and diethanolamine (DEA) respectively using microwave oven, (power less or equal to 600 w ) for 20 minutes. The products were characterized by FTIR spectroscopy then evaluated as corrosion Inhibitors for Carbon steel in 0.1 M HCl at different temperatures using Taffel plots and Electrochemical Impedance Spectroscopy (EIS) techniques. The obtained results showed that the Inhibition Efficiency (%E) increased up to 76% and 83% for BHETA and THETA respectively. The adsorption isotherm was investigated using Langmuir equation, and the obtained results confirmed the occurrence of physico adsorption that occurs between the Inhibitor and surface of the metal, and the thermodynamic functions were calculated) ads. The coating properties of 25% w\w of each BHETA and THETA with commercial acrylic paint were evaluated using EIS technique and showed that the efficiency of coating increased up to 89% and 93.6% when adding BHETA and THETA respectively. [ABSTRACT FROM AUTHOR]

With 80% of Florida’s residents living within 10 miles of the coast, Florida’s aquatic resources are directly affected by urbanization. The intent of this new 6-page publication of the UF/IFAS Department of Soil and Water Sciences is to describe the urban nitrogen cycle for a non-technical audience. Ultimately, this document is intended for individuals working in urban environments and concerned about nutrient pollution and water quality issues, but do not have a technical background and want to improve their understanding of nitrogen cycling. Written by Alexander J. Reisinger, Mary G. Lusk, and Ashley R. Smyth. https://edis.ifas.ufl.edu/ss681

The use of post-consumer plastics in concrete production is an ideal alternative to dispose of such wastes while reducing the environmental impacts in terms of pollution and consumption of natural resources and energy. This paper investigates different approaches (i.e., reducing water-to-cement ratio and incorporating steel fibers or polymeric latexes) that compensate for the detrimental effect of waste plastics on the drop in concrete mechanical properties including the bond to embedded steel bars. The polyethylene terephthalate (PET) wastes used in this study were derived from plastic bottles that were shredded into small pieces and added during concrete batching at 1.5% to 4.5%, by total volume. Test results showed that the concrete properties are degraded with PET additions, given their lightweight nature and poor characteristic strength compared to aggregate particles. The threshold PET volumetric rates are 4.5% and 3% for concrete made using natural or recycled aggregates, respectively. The reduction of w/c from 0.55 to 0.46 proved efficient to refine the matrix porosity and reinstate the concrete performance. The incorporation of 0.8% steel fibers (by volume) or 15% polymers (by mixing water) were appropriate to enhance the bridging phenomena and reduce the propagation of cracks during the pullout loading of steel bars.

Resin concretes belong to a small group of building materials which, besides high strength parameters, also have a very good chemical resistance. This is confirmed by the studies carried out by various research institutions around the world. However, there is little data on the behaviour of composite resin exposed to corrosive solutions for an extended period of time. This article presents the results of the research on weight changes in samples of epoxy mortar modified with poly(ethylene terephthalate) glycolysates, immersed for 5 years in four different aggressive media i.e. 10% aqueous solutions of sulphuric and nitric acids, sodium hydroxide, and sodium chloride. The actual average weight changes obtained were compared with the data calculated on the basis of the regression functions fitted to the data recorded after 3.5 years of exposure. This allowed verification of the model selection correctness and evaluation of the effectiveness of the fitted regression curve. In the case of aqueous sodium hydroxide and sodium chloride solutions, it can be assumed that the logarithmic model describes weight changes well. It was observed that the weight of the samples exposed to NaCl solutions and NaOH stabilizes over prolonged monitoring time and reaches a plateau. However, the weight changes in mortar samples immersed for 5 years in aqueous solution of sulphuric and nitric acids quite significantly differ from the data calculated on the basis of the trend line fitted to the results of the tests carried out after 3.5 years of exposure. It seems that the better solution in this case is the selection of an exponential model. In addition, placing the logarithmic trendlines for all corrosive media together on a chart allows to note which of the solutions is the most aggressive. It was found that after 5 years of immersion in aqueous solutions of acids, mortar samples became brittle, and the observation of their fractures confirmed the weakness of the connection on the resin/aggregate phase boundary. Changes in the appearance of the samples were also noted, namely the surface of samples submerged in a solution of nitric acid strongly yellowed, and those treated with sulphuric acid were tarnished.