Plastic pollution has emerged as a pervasive environmental threat, with polyvinyl chloride (PVC) being a persistent polymer that can degrade into smaller fragments. These particles contaminate aquatic environments, accumulate in biota, and pose serious ecological and health risks. This study used computational methods to investigate the adsorption of vinyl chloride (VC), a PVC oligomer, onto montmorillonite (MMT). Vienna Ab initio Simulation Package was used to perform Density Functional Theory calculations. The interaction between VC and MMT was assessed through binding energy, density of states (DOS), projected DOS, and charge analysis. A negative binding energy (- 0.62eV) confirmed favorable adsorption. The reduced HOMO-LUMO gap in the VC-MMT hybrid indicated electronic interactions. The orbital-resolved projected density of states (PDOS) showed overlap between the O 2p orbitals of MMT and the H 1s orbitals of VC. Bader charge analysis revealed negligible charge transfer to the VC molecule upon adsorption, while charge density difference showed localized electron redistribution at the VC-MMT interface. These results indicate a noncovalent interaction without the formation of shared charge density, consistent with polarization-driven physisorption. Molecular dynamics simulations supported these interactions, showing that the VC molecule remained associated with the MMT surface through noncovalent forces. Root mean square deviation (RMSD) confirmed that the VC-MMT structure remained stable throughout the simulation, while the interaction energy exhibited stable fluctuations over time. These findings suggest that MMT holds potential as an effective sink for PVC microplastics through stable, non-covalent surface retention, thereby reducing their dispersion in environmental matrices.

The recycling of polyolefin plastics is often hindered by high energy consumption and low economic efficiency. In particular, the recycling of poly(vinyl chloride) is especially challenging. Here, we present a protocol to recycle poly(vinyl chloride) into a photothermal agent for the depolymerization of polyolefins under sunlight. By dechlorinating the poly(vinyl chloride), we harness its unique ability to convert sunlight into the energy required to break C-C bonds in polyolefins. This protocol allows for the transformation of low-density polyethylene, high-density polyethylene, and polypropylene into waxes enriched with terminal olefins. Furthermore, it can also enable the conversion of polystyrene, poly(methyl methacrylate), poly(α-methyl styrene), styrene-acrylonitrile copolymer, and acrylonitrile-butadiene-styrene into their respective monomers. This broad applicability makes our protocol suitable for recycling of a wide range of post-consumer plastics and their mixtures under ambient environment. This work provides an effective strategy for polyolefins recycling using waste plastics and solar energy.

Ethane chlorination has emerged as a promising alternative to conventional ethylene- and acetylene-based routes for the production of vinyl chloride monomer (VCM). Unlike conventional catalytic processes, this approach relies on chlorine radical-mediated activation to convert ethane into 1,2-dichloroethane, followed by thermal cracking to VCM. However, this route remains in its early stages, hindered by the complexity of gas-phase radical chemistry and catalyst deactivation under chlorination conditions. This review provides a critical assessment of the mechanistic foundations of ethane chlorination, highlighting the interplay between radical-mediated and surface-catalyzed pathways. Particular attention is given to advances in rare-earth oxychloride catalysts, which have shown the ability to stabilize key intermediates. We also discuss major deactivation mechanisms, including phase transformation and surface hydroxylation, that limit catalyst lifetime. Furthermore, we highlight the feasibility of ethane chlorination as a low-carbon VCM production route under future decarbonized energy scenarios. Finally, key directions in catalyst design, mechanistic understanding, and process integration are outlined to advance ethane chlorination from laboratory-scale innovation to industrial reality.

Investigation of dedoping-redoping properties of novel poly(vinyl chloride)/ polyisoprene/ polypyrrole ternary composites

Microplastics (MPs) are pervasive in river sediments, where surface biofilm formation critically regulates their environmental behavior. However, mechanisms governing the dynamic MP-biofilm interactions remain underexplored. A 60-day in situ sediment incubation, coupled with continuous monitoring of MP physicochemical properties and microbial community characteristics, was conducted to elucidate the interactions between biofilms and MPs with different polymer types (poly(ethylene terephthalate) (PET), polypropylene (PP), and poly(vinyl chloride) (PVC)) and preaging experiences. In the early stage, biofilm development was promoted by oxygen-containing functional groups (OFGs) of MPs, whereas the additive release from PVC suppressed microbial enrichment. Eventually, both the biofilm biomass and extracellular polymeric substances depended strongly on polymer types. Over time, biofilms progressively modified MP surface chemistry, increasing the O/C ratios of PVC, PET, and PP by 0.41, 0.26, and 0.11, respectively, by producing extracellular proteins, especially plastic-degrading enzymes. Therefore, a temporal feedback loop formed in which MP-derived OFGs acted as nutrient sources, reshaping the microbial community structure and selectively enriching plastic-degrading taxa and enzymes, which in turn accelerated MP degradation. This study provides novel insights into the dynamic reciprocal interactions between MP surface chemistry and biofilm communities and advances our understanding of the mechanisms controlling the ecotoxicity and fate of MPs in river sediments.

Innovative active carbon fibers-based multipurpose thermal desorption tubes for the analysis of volatile organic compounds.

Mechanical force has the potential to activate thermodynamically and chemically stable molecules, enabling unique reactions to proceed with lower activation energies compared to those of conventional thermal activation pathways. However, the practical utility of such force-driven transformations in synthetic chemistry remains to be demonstrated. In this study, we developed a mechanochemical strategy for the facile activation of poly(vinyl chloride) (PVC), a stable plastic material, as a convenient and practical hydrochloric acid (HCl)-releasing reagent. Although HCl can be generated from PVC via thermal decomposition processes, elevated temperatures (>250 °C) are required, which restrict their practical applications in chemical synthesis. In contrast, our mechanochemical approach leverages the mechanical energy generated via ball milling to induce the homolytic cleavage of the polymer chains, producing HCl under mild conditions. Preliminary calculations support that our proposed force-induced mechanoradical-related mechanism generates HCl with lower activation energies than thermal activation. Inspired by this finding, we demonstrate the applicability of PVC as a mechanotunable Brønsted-acid-releasing reagent to facilitate direct SN1-type substitution reactions of allylic and benzylic alcohols with electron-rich (hetero)aromatics, amines, and alcohols as nucleophiles under mild, solvent-free, and moisture-tolerant mechanochemical conditions. Moreover, these reactions proceeded efficiently using PVC-based plastic waste, such as PVC tubing. Beyond the immediate utility of this protocol, this work can be expected to inspire the development of mechanochemical approaches to activate stable, abundant commodity plastic materials for their valorization as chemical reagents in the synthesis of high-value molecules.

Polyvinyl chloride (PVC) has raised significant environment concerns due to its chlorine-rich composition. Mechanochemical dechlorination of PVC produces waste chlorides that remain largely unutilized. Herein, we demonstrate that contact-electro-catalysis-mediated dechlorination, in tandem with alcohol chlorination can enable the upcycling of PVC to produce value-added organic chlorides and enhance atomic efficiency. Anatase TiO2, as contact-electro-catalyst, mediates the single electron transfer process that promotes the dechlorination of PVC under ball milling, thereby enabling the cascade alcohol chlorination through in-situ generated HCl. This strategy is applicable to a variety of benzylic, alicyclic, aliphatic and heterocyclic alcohols, yielding the corresponding organic chlorides with yields up to 95% in 4 hours. This mechanochemical approach can be scaled up to a 40 g scale of PVC and applied to real PVC samples. Structural analysis confirms the effective degradation of PVC accompanied by dechlorination with molecular weight decreasing from 65.0 kDa to 4.6 kDa after five cycles. This mechanochemical approach opens avenues for the application of PVC as a convenient and safe chlorine source in chemical transformations.

The miscibility of chlorinated polyethylene (CPE)/polyvinyl chloride (PVC) blends is intricately influenced by both chemical structures and environmental conditions. This study employs all-atom molecular dynamics simulations to systematically investigate the effects of CPE chlorine content and molecular architecture, blend composition, and temperature on CPE/PVC miscibility behavior. Analysis of solubility parameters (δ) suggests that the compatibility of CPE/PVC blends improves with increasing chlorine content within the examined range. Random-chlorinated polyethylene (r-CPE) demonstrates superior miscibility with PVC compared to block-chlorinated polyethylene (b-CPE), attributed to enhanced electrostatic contributions arising from intensified polar Cl–Cl interactions. CPE/PVC blends containing approximately 20–80 wt% CPE are found to be thermodynamically immiscible at 300 K. Furthermore, a quantitative relationship between the Flory–Huggins interaction parameter (χ12) and temperature (T) is established, revealing an increase in χ12 with T, indicative of reduced miscibility at higher temperatures. The phase diagram exhibits a low critical solution temperature (LCST) behavior, consistent with the χ12–T relationships. Notably, r-CPE/PVC binary systems exhibit a higher LCST critical temperature (Tcr) than b-CPE/PVC systems. In general, this simulation study provides better understandings of CPE/PVC miscibility and offers valuable guidance for the design and optimization of CPE/PVC composite materials.

Thermoresponsive self-assembly of amphiphilic poly(N-vinylcaprolactam)-b-poly(vinyl chloride) diblock copolymers: From controlled synthesis to stable nanoparticles

Hyperbranched polyamine-graft-poly(ε-caprolactone) with integrated flame retardancy, plasticization, and filler-dispersion functions toward high-performance poly(vinyl chloride) plastics

Use of carbon-14 trichloroethene to determine degradation rate constants in rock core microcosms.

Metal-free electrocatalytic dechlorination of chlorinated ethenes using bifunctional biochar cathode: adsorption-coupled electrocatalytic reduction mechanism.

Effect of side chain length on the miscibility and hydrogen bonding interactions of CO2-based copolymers blending with poly(vinyl phenol) and poly(vinyl chloride)

Biochar-assisted detoxification of groundwater trichloroethene: Mitigating vinyl chloride accumulation and environmental risks via Dehalococcoides mccartyi-containing consortium.

Graphene-supported micron zero-valent iron cooperates with immobilized microorganisms for long-term efficient chlorinated organics remediation.

The development of efficient CH3Cl-to-C2H3Cl catalysts remains challenging due to the poor dispersion of Na2WO4 at high loadings, which limits catalytic performance. This study addresses this issue by employing silicon carbide (SiC) as a support, which undergoes an in situ phase transformation to α-cristobalite during calcination, effectively enhancing Na2WO4 dispersion even at 35 wt% loading. The resulting catalyst achieved a vinyl chloride selectivity of 35.1% and a yield of 31.4% at 700 °C, significantly outperforming conventional Na2WO4/SiO2 catalysts synthesized with α-cristobalite. These findings highlight the importance of support-mediated phase transformations in designing high-performance MCTV catalysts, offering a sustainable pathway for VCM production.

Oxygen vacancy engineering by La-incorporation into Co3O4 matrix for boosting catalytic oxidation of vinyl chloride: experimental and DFT evidences

This study evaluated the dietary effects of freshwater microalga, Spirulina platensis on the growth performance, nutrient utilisation and stress biomarkers in Koi carp, Cyprinus carpio fingerlings raised in aquaponic system with fluted pumpkins. Five feeds were formulated with different inclusion levels of spirulina at 0, 25, 50, 75 and 100% each representing treatment 1 (control), 2, 3, 4 and 5 respectively. The aquaponic system used is a pyramid Nutrient Film System (NFT) using a Poly Vinyl Chloride base with a small hole made for plant to float placed in a small disposable plastic filled with growth media and conventionally used Gravel (granite stones) which was used as control to support the plants for the plant to grow. The result showed that were significant differences (P<0.05) in the growth and nutrient utilization parameters with treatment 4 with 75% spirulina inclusion having the best protein efficiency ratio, feed conversion and feed efficiency ratios. The results from the stress biomarker analysis indicated that Spirulina platensis reduced liver stress and enhances liver function in Cyprinus carpio fingerlings, as evidenced by the decreasing ALT and AST levels in the liver of fish with spirulina diets.

Microplastics are pervasive environmental pollutants, making human exposure unavoidable. Although previous studies have detected microplastics in human blood and feces, these investigations were limited by small sample sizes and key contributors to microplastic biomonitoring remain underexplored. In this study, we analyzed 229 blood and 227 fecal samples using pyrolysis-gas chromatography-mass spectrometry to quantify microplastic exposure and identify key influencing factors through machine learning modeling. Seven polymer types were detected in both biological matrices, including polyethylene, poly(vinyl chloride) (PVC), polypropylene, polystyrene, polyamide 66, poly(ethylene terephthalate), and poly(methyl methacrylate), with polyethylene, PVC, and polystyrene being the most prevalent. A significant negative correlation was observed between blood and fecal PVC levels, while other polymers showed no significant intermatrix association. Demographic, lifestyle, socioeconomic, and dietary information were collected via questionnaires. Age, sex, geographic, and indoor environmental variations in microplastic levels were observed. Machine learning models were developed to predict microplastic levels from anthropometric measurements and questionnaire data. Explainable AI tools revealed that the drinking water source was the strongest predictor of blood PVC levels. Socioeconomic factors, including income and education, were also significant predictors, with lower-income individuals showing higher microplastic burdens. This approach provides a framework for understanding and mitigating microplastic exposure.