Polymer Degradation Research Articles

Ultraviolet (UV) radiation is the major cause of polymer degradation in outdoor environments, accelerating mechanical failure and color change, leading to plastic waste accumulation. Effective UV-protective strategies that preserve polymer functionality are therefore critical for extending material longevity in UV-intense environments. Here, we present a synergistic approach combining vapor phase infiltration (VPI) and atomic layer deposition (ALD) to engineer nanoscale zinc oxide (ZnO) coatings on poly(lactic acid) (PLA), a UV-sensitive polymer. Individually, ALD and VPI offer minimal enhancement in UV stability; however, their sequential application enables the formation of conformal, polycrystalline ZnO films that dramatically improve UV resistance in both 3D-printed structures and thin-film PLA models. In situ microgravimetry and cross-sectional electron microscopy reveal that VPI introduces ZnO nucleation sites within and atop the polymer matrix, promoting a >10-fold increase in ZnO growth per ALD cycle. The resulting ZnO-PLA hybrids absorb over 90% of incident UV-C radiation while maintaining high optical transparency in the visible range. This low-temperature, scalable process provides a promising platform for the development of transparent, durable UV-barrier coatings on polymers for use in environmentally demanding applications.

Sediments microplastics along three Ethiopian Rift Valley lakes demonstrated variation in polymer composition and moderate contamination level.

Iterative enhancement of cutinase thermostability by multiple strategies based on combined directed evolution and computationally assisted design.

Design and photocatalytic performance of Cd(II)-based coordination polymers for selective PNP degradation

Carboxylic ester hydrolases from Antarctic psychrophilic Psychrobacter strains: From genome prospecting to biotreatment of polyester plastics.

Long-term controlled in vitro release of FITC-dextran using polymer-based drug delivery systems manufactured by semi-solid extrusion 3D printing.

Precise macrophage modulation is essential for diabetic wound treatment, yet mitochondrial dysfunction often sustains proinflammatory states. We developed cascade-targeting nanoparticles [epigallocatechin-3-gallate and metformin nanoparticles modified with mannose (EM/Man NPs)] to regulate macrophage mitochondria, integrated into a detachable core-shell microneedle patch (EM/Man MNs) made of quaternary ammonium chitosan and reactive oxygen species (ROS)–degradable polymer. The patch offered high penetration and antibacterial activity, while its ROS-sensitive core released EM/Man NPs to scavenge ROS, restore adenosine 5′-triphosphate production, and reestablish redox balance. The NPs further activated the adenosine 5′-monophosphate–activated protein kinase/Sirtuin 1/peroxisome proliferator–activated receptor gamma coactivator 1α axis to promote mitochondrial biogenesis and oxidative phosphorylation, repolarizing macrophages to an anti-inflammatory phenotype. In diabetic mice, EM/Man MNs accelerated healing via bacterial clearance, immune reprogramming, angiogenesis, and collagen deposition while inhibiting scar formation through interleukin-17 and phosphatidylinositol 3-kinase–Akt suppression. This cascade-targeting strategy for modulating macrophage mitochondria to regulate immunity and redox homeostasis provides a previously unidentified approach for designing tissue engineering materials.

Fossil fuels are currently the primary source for plastic production, with global production exceeding 400 million tons annually. The food sector remains the dominant application, particularly in the production of single-use packaging. Commonly used packaging is primarily made from PE, PP, PS, and PET. The versatility of these materials stems from their lightweight, functionality, and ability to extend the shelf life of food products. Unfortunately, constantly growing consumption generates vast amounts of difficult-to-degrade waste, which in the natural environment constantly fragments, generating hazardous microplastics (MPs). MPs readily spread throughout the biosphere and are now commonly detected in the digestive tracts of humans and animals. Current scientific reports indicate their potential contribution to the pathogenesis of numerous diseases such as inflammatory bowel disease, diabetes, obesity, allergic reactions, and cancer. This link is believed to result from mechanisms involving physical toxicity, exposure to chemical substances, and microbiological interactions. The MP problem is global in nature and encompasses the entire life cycle of plastics, from production to accumulation in living organisms. This review aims to provide an up-to-date and comprehensive overview of the toxicological and environmental issues related to MPs, addressing the current research gaps and emphasizing their increasing relevance to human health.

Carbon nanotubes (MWCNTs) were synthesized in situ on para-aramid fabrics (gCPO) via a low-temperature (450 °C) chemical vapor deposition (CVD) process to enhance interfacial pull-out, frictional, and fracture toughness characteristics. FESEM analysis confirmed CNT coverage on fiber surfaces, while FTIR, Raman, and XRD results indicated limited structural modification without significant polymer degradation. The CNT-functionalized fabrics exhibited a 66.19% increase in maximum pull-out force, 55.32% improvement in interlacement rupture strength, and a three-fold rise in intra-yarn shear resistance compared with control fabrics (KPO). The static and kinetic friction coefficients increased by 26.67% and 16.67%, respectively, due to CNT-induced surface roughness, enhancing inter-fiber load transfer and reducing slippage. Single-yarn pull-out tests revealed notable gains in energy dissipation and fracture toughness (up to 1769 J/m2), whereas multi-yarn pull-out performance decreased due to excessive friction surpassing filament strength. The study demonstrates that low-temperature MWCNT growth enables effective interfacial reinforcement of soft para-aramid fabrics, establishing a novel framework for meso-scale mechanical screening of flexible nano-ballistic composites.

Background/Objectives: Although significant advances in duodenoscope reprocessing have been introduced since mid-2010s—including enhanced cleaning protocols, disposable distal endcaps, and the introduction of fully single-use duodenoscopes—residual contamination and infection risks remain unresolved. Moreover, repeated reprocessing may cause cumulative damage to the polymer surfaces, elevator mechanisms, and internal channels of the duodenoscopes, making them more susceptible to residual contamination. To minimize the duodenoscope polymer degradation caused by intensive use and reprocessing, new alternatives are urgently needed. In this context, calcium peroxide nanoparticles coated with sodium alginate (CaO2–Alg NPs), synthesized by our group, were tested for the first time as a disinfectant capable of combating nosocomial pathogens while reducing device deterioration associated with repeated investigations and reprocessing. Methods: The disinfectant properties of the CaO2–Alg NPs were evaluated under biomimetic conditions using reference bacterial strains commonly associated with nosocomial infections. In addition, the compatibility of the nanoparticles with the polymeric duodenoscope coatings was assessed after simulated intensive use. The external polymer coating was structurally and morphologically characterized by Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), Atomic Force Microscopy (AFM), and Scanning Electron Microscopy (SEM). Results: The nanoparticles exhibited important antimicrobial activity against the reference bacterial strains Staphylococcus aureus, Escherichia coli, Enterococcus faecalis, and Klebsiella pneumoniae after only 20 min of incubation. Intensive exposure to the CaO2–Alg NPs did not cause additional structural or morphological damage to the duodenoscope’s external polymers and did not alter their anti-adhesive properties. Conclusions: The CaO2–Alg NPs appear to be a safe and effective disinfectant for the duodenoscope reprocessing, offering both antimicrobial efficacy and material compatibility.

Abstract Fluorination of polymers is a powerful strategy to enhance chemical or material properties yet integrating these benefits into degradable polymers remains underexplored. Here, we report a new class of fluorinated polyesters synthesized via ring‐opening copolymerisation of pentafluoro styrene oxide with phthalic anhydride. The pendant C6F5 groups accelerate catalysis through fluorine‐specific π‐stacking interactions and improve obtained molecular weights compared to the non‐fluorinated variant giving access to high weight materials (Mn,max. > 100 kg mol−1) with thermal and mechanical properties competitive with commodity plastics. These C6F5 groups then act as reactive handles in the material for efficient post‐polymerisation modification (PPM) in solution, allowing fine‐tuning of thermal, mechanical, optical, and solubility properties. PPM can even be performed on material surfaces, films and fibres can be selectively modified without dissolution. Lastly, degradation enables quantitative recovery of fluorine centres as sodium fluoride, offering a sustainable end‐of‐life option for the incorporated fluorine. Our work demonstrates how targeted fluorination of degradable polyesters can simultaneously enhance catalysis and unlock advanced material functionality.

Fluorination of polymers is a powerful strategy to enhance chemical or material properties yet integrating these benefits into degradable polymers remains underexplored. Here, we report a new class of fluorinated polyesters synthesized via ring-opening copolymerisation of pentafluoro styrene oxide with phthalic anhydride. The pendant C6F5 groups accelerate catalysis through fluorine-specific π-stacking interactions and improve obtained molecular weights compared to the non-fluorinated variant giving access to high weight materials (Mn,max. > 100kgmol-1) with thermal and mechanical properties competitive with commodity plastics. These C6F5 groups then act as reactive handles in the material for efficient post-polymerisation modification (PPM) in solution, allowing fine-tuning of thermal, mechanical, optical, and solubility properties. PPM can even be performed on material surfaces, films and fibres can be selectively modified without dissolution. Lastly, degradation enables quantitative recovery of fluorine centres as sodium fluoride, offering a sustainable end-of-life option for the incorporated fluorine. Our work demonstrates how targeted fluorination of degradable polyesters can simultaneously enhance catalysis and unlock advanced material functionality.

This study quantitatively evaluated the surface degradation of cycloolefin polymer (COP) films after vacuum ultraviolet (VUV) irradiation and oxygen plasma treatment. Surface degradation was quantified using the strength ratio, defined as the erosion resistance normalized to its bulk value, as measured by the micro slurry-jet erosion (MSE) test that enables depth-resolved evaluation of near-surface mechanical properties. VUV irradiation induced considerable surface degradation, reducing the strength ratios at the surface to approximately 28% and 32% at VUV irradiation doses of 600 and 1,200 mJ/cm2, respectively. However, strength ratios gradually recovered to the bulk value (100%) over a depth of approximately 1,200 nm, irrespective of the VUV irradiation dose. Conversely, oxygen plasma treatment caused moderate surface degradation, with the strength ratio at the surface decreasing to approximately 84% and 69% for oxygen plasma treatment times of 60 and 120 s, respectively. However, the strength ratio rapidly recovered to the bulk value within a depth of approximately 30 nm, regardless of the oxygen plasma treatment time. Previous peel tests between the COP film and the copper plating layer with a sputtered copper seed layer revealed substrate failure within 10 nm of the surface after VUV irradiation at 600 and 1,200 mJ/cm2, but not after oxygen plasma treatment for 60 and 120 s, indicating that a strength ratio of at least 69% is required to prevent substrate failure. Although further investigations are required to refine the critical threshold, the present framework provides a quantitative approach for evaluating the surface degradation characteristics.

The development of efficient and controlled polymerization techniques to synthesize degradable polymers is crucial for advancing sustainable plastics. We report a mild and highly efficient strategy for the synthesis of degradable copolymers via visible light-mediated photoiniferter polymerization. Using a commercially available dithiocarbamate compound as a photoiniferter, we achieved the rapid copolymerization of a lipoic acid derivative with various acrylate and acrylamide monomers under benign blue light irradiation (462 nm) at 40 °C. This method provides exceptional temporal control and yields well-defined copolymers with predictable molecular weights, low dispersities, and tunable disulfide content. The resulting copolymers undergo efficient degradation to low molecular weight oligomers through air oxidation or dithiothreitol reduction. This photoiniferter approach establishes a versatile and sustainable platform for the precise synthesis of degradable polymers from renewable sources and commercially accessible monomers.

Microplastics (MP) are an emerging contaminant in organic waste recycling, yet their occurrence and fate in anaerobic digestion (AD) systems remain poorly understood due to challenges in isolating MP from complex matrices. This study developed and validated a novel extraction method using peroxide oxidation and an EDTA–Triton X-100 solution that achieved >96% recovery without polymer degradation. This method was applied to characterize MP in manure, digester effluent (digestate), and lagoon storage at a full-scale food waste–manure co-digestion facility. MP were consistently detected across all sources, with concentrations ranging from 120 MP kg−1 (manure) to >3,300 MP kg−1 (lagoon). Abundance was highly variable over time, shaped by feedstock composition and digester management practices. The MP observed likely stemmed from multiple pathways, including food waste inputs, packaging residues, on-farm sources, atmospheric deposition, and fragmentation of larger plastics during digestion. Polyethylene terephthalate (PET) fibers dominated across all samples. These findings provide the first quantitative evidence of microplastic (MP) occurrence throughout the AD process and highlight how management decisions influence contamination. By advancing extraction methods and generating new field-scale data, this study establishes a foundation for assessing the risks of MP release from AD systems to agricultural soils and downstream ecosystems.

This work provides a comparison of two commercial carbon fiber reinforced plastic (CFRP) materials: HexPly® M18 1/G939 and RTM6/G939. Differences due to the additional thermoplastic in one CFRP are investigated for the two otherwise nearly identical, aromatic epoxy-based composites with respect to thermal degradation. The scenario chosen for testing is based on real incidents of repeated overheating by hot gases between roughly 200 and 320 °C, leading to moderate thermal damage. A special test setup is designed to continuously and alternately load CFRP with hot air in a rapid change. Post-mortem analysis is performed by mass loss, ultrasonic, and mechanical testing. Polymer degradation is analyzed by infrared spectroscopy. Even if the temperature-resistant thermoplastic polyetherimide (PEI) in the M18-1 matrix is enriched between the plies and a compensation of thermal strain during rapid temperature changes is expected, only a weak improvement is observed for residual strength in the presence of PEI, for continuous as well as alternating thermal loading. Thermally induced delaminations are even more pronounced in M18-1/G939. Deep insight is gained into degradation after repeated overheating of CFRP within the chosen scenario. Multivariate data analyses based on infrared spectroscopy allow for the determination of thermal history and residual strength, valuable for failure analysis.

This JOCSynopsis underscores the pivotal role of 5-exo-trig and 6-exo-trig cyclization pathways in directing ring-closure reactions, with a focus on their application to the modification of biotic polymers, including amino acid labeling and N-terminal capping strategies in peptide stapling. This work extends these cyclizations to the degradation of both abiotic and biotic polymers. It also explores instances where degradation occurs through less favorable cyclization pathways, highlighting the complexity and context-dependence of these transformations. Additionally, it showcases the use of 5-exo-trig cyclization in reversible click chemistry, emphasizing its role in the design of dynamic materials. These insights are exemplified by systems such as a Meldrum's acid-derived conjugate acceptor, which can undergo reversible "click" and "declick" processes, paving the way for the development of polymers with tunable and responsive properties.

Using pineapple fiber, coir fiber, and banana fiber as a polymer reinforcement to develop sustainable composites reduces environmental pollution. This review emphasized the progress in development of composite materials based on pineapple fiber, coir fiber, and banana fiber and critically examined the influence of fiber loading and fiber size, fiber modification, micro and nanofillers, and hybridization on the properties of composite materials fabricated with several polymer matrices. This review has been specifically categorized according to the type of matrix materials used, which include conventional polymers, bio degradable polymers, and recycled polymers. The mechanical performance of hybrid composites based on pineapple fiber, coir fiber, and banana fiber fabricated with other natural and synthetic fiber composites was better than the individual fiber. Incorporation of filler materials such as alumina, SiC, nanoclay, eggshell powder, and nano-cellulose provided a significant enhancement in mechanical properties of composites. Alkaline and silane treatment of fiber is the most commonly used treatment method, and this treatment significantly enhances mechanical, thermal, and water resistance properties of composites. Life cycle assessment analysis and long-term durability analysis of composites, optimization of fiber treatment parameters for better performance of composites, and 3D printer filament development based on nano-cellulose extracted from banana, coir, and pineapple are future directions for developing sustainable materials.

Anti-stripping agents (ASAs) have become a mandatory inclusion in bituminous mixtures containing hydrophilic aggregates and in regions experiencing extreme rainfall. Even with superior binders such as polymer-modified bitumen (PMB), ASAs are added to enhance moisture resistance in high-stress locations such as airfields, where significant pavement stresses and a strict zero-failure policy are critical for safety. This study deeply probes the rheological change in the behavior of PMB because of the addition of liquid ASAs: amine and silane. The performance of ASAs is analyzed from the perspective of cohesion, rutting, fatigue, and aggregate-bonding properties. Artificial aging of binders was performed to imitate short-term and long-term aging conditions using a rolling thin film oven and then a pressure aging vessel, respectively. A series of tests were conducted, which included FTIR (Fourier transform infrared spectroscopy), high performance grade temperature, Bitumen-Typisierungs-Schnell-Verfahren, rotational viscosity, force ductility, MSCR (multiple stress creep recovery), the BYET (binder yield energy test), and binder bond strength. FTIR tests evinced chemical rearrangement and polymer degradation because of the addition of ASAs in the PMB. MSCR analysis at multiple stress levels indicated a drop in rutting resistance with the presence of ASAs at high stresses and temperature, stipulating a loss of recovery property. The novel BYET measured the fatigue resistance of long-term aged binders and demonstrated that ASAs cause early yielding of binders. The addition of ASAs improved the bond strength of PMB with limestone, basalt, and quartzite aggregates. Comprehensively, this study concludes that ASAs have an impact on the rheology of PMB; however, there is a compromising of certain binder properties to attain the benefits of moisture resistance.

An optimal valve replacement prosthesis demands durable leaflet technology, superior hemodynamic performance, and ease of use. Preclinical evaluation of polymer leaflets has historically demonstrated mechanical failure related to biodegradation. We present the preclinical evaluation of the novel TRIA™ polymer valve (Foldax, Salt Lake City, UT, USA) and a case report of TRIA mitral valve replacement. A uniquely formulated, biostable, and biocompatible polymer (LifePolymer™ [LP], Foldax) has been designed to meet the functional demands of cardiac hemodynamics. Preclinical in vitro evaluation included biocompatibility testing, thrombogenicity testing, and toxicologic assessment followed by evaluation in the arteriovenous shunt of nonhuman primates and in the aortic position in sheep. Clinical evaluation of early human aortic and mitral implantation included computed tomography imaging and echocardiographic examination. In vitro studies of LP demonstrated no evidence of toxicity or tissue injury, no cytological injury in cell culture, and no intracutaneous sensitization. LP proved to be nonhemolytic by direct and extract methods, and complement activation was insignificant. Genotoxicity analysis proved LP to be nonmutagenic. All standard toxicologic assessments were within the margin of safety. Biostability was confirmed without polymer degradation or excessive comparative thrombogenicity. Ovine 6-month aortic valve explantation showed no leaflet calcification and minimal fibrinous depositions. An early human case example shows no evidence of leaflet thrombus formation at 6 months and a mean mitral gradient of 3 mm Hg at 12 months. LP has met the requirements for a prosthetic polymer human heart valve. The surgical TRIA Mitral Valve has demonstrated promising early human clinical success, potentially facilitating a lifetime valve replacement strategy.