Degradation Of Polypropylene Research Articles

Environmental Degradation Study of Polypropylene Films Incorporating Pro-Oxidants: Comprehensive Analysis and Ecotoxicological Assessment

Our research described in this paper investigated the environmental degradation of polypropylene (PP) films incorporating pro-oxidants and assessed their impact on the ecosystem. Weathering aging effects were monitored through Fourier-Transform Infrared (FTIR) analysis, revealing significant changes in carbonyl, hydroxyl and amorphous regions post-aging. The presence of pro-oxidants intensified these changes, indicating higher oxidation levels. Contact angle measurements demonstrated decreased hydrophobicity upon aging, particularly pronounced in pro-oxidant-containing films (initial contact angle: 87.79° for PP/1% Co/1% Fe, sample (F6) decreased to 79.24° after aging). Differential Scanning Calorimetric (DSC) analysis revealed decreased melting temperatures (initial Tm: 159.5 °C for F6 decreased to 148 °C after aging) and the crystallinity post-aging (initial χ: 73.25% for F6 decreased to 60.17% after aging), suggesting increased susceptibility to degradation. Thermogravimetric Analysis (TGA) showed decreased thermal stability after aging, especially in PP/pro-oxidant films; the Tonset (T5); 432.00 °C for F6, decreased to 268.00 °C after aging; where Tonset is the temperature corresponding to 5% weight loss. Biodegradation tests indicated enhanced biodegradability in the pro-oxidant-containing films, with cobalt and ferrous stearate mixtures showing the highest degradation degrees (e.g., PP/1% Co/1% Fe: ≈ 77% biodegradation after 140 days). Ecotoxicological evaluations, including microbial toxicity and plant germination and growth tests, revealed no inhibitory effects of the degradation products on soil flora or plant growth, confirming their nontoxic nature. Overall, we believe this comprehensive study provides insights into the environmental fate of PP films with pro-oxidants, highlighting their potential for accelerated degradation without adverse ecological impacts.

An integrated approach for plastic polymer degradation by the gut bacterial resident of superworm, Zophobas morio (Coleoptera:Tenebrionidae).

The potential of superworm to remove certain plastic polymers has recently been noted. In this study, aerobic bacterial strains were isolated from the gut of Zophobas morio larvae which were fed with polyethylene (PE), polyethylene terephthalate (PET), polypropylene (PP), and polystyrene (PS) polymers. Strains P2 (Leminorella), P6 (Bacillus), P9 (Bacillus), and P5 (Citrobacter) were associated with the highest PS (2.7%), PP (1.3%), PET (1.1%), and PE (0.42%) weight loss after 28days, respectively. Pretreatments including thermal treatment (80°C for 10days), weathering (4months in the free environment), and nitric and sulfuric acids (1 N, 10days) improved the degradation of PE (1.3%), PET (1.9%), PP (5.2%), and PS (8.3%) by the same strains, respectively. Further analyses on the PS degradation by Leminorella sp. P2 revealed acid pretreatment promoted the formation of the C = C, C = O, and O-H functional groups. Surface irregularities, as well as a 3.6-fold increase in surface roughness, were observed in the PS film subjected to biodegradation. The contact angle dropped from 98.4° to 42.2° following the biodegradation. Bacterial depolymerization was confirmed by the 8.7% and 3.4% reduction of Mn and Mw and the change in polydispersity from 1.65 to 1.75. The results suggest that Zophobas morio microbiota in combination with abiotic pretreatment can be considered for plastic waste management.

Isolation and Identification of Four Strains of Bacteria with Potential to Biodegrade Polyethylene and Polypropylene from Mangrove.

With the rapid growth of global plastic production, the degradation of microplastics (MPs) has received widespread attention, and the search for efficient biodegradation pathways has become a hot topic. The aim of this study was to screen mangrove sediment and surface water for bacteria capable of degrading polyethylene (PE) and polypropylene (PP) MPs. In this study, two strains of PE-degrading bacteria and two strains of PP-degrading candidate bacteria were obtained from mangrove, named Pseudomonas sp. strain GIA7, Bacillus cereus strain GIA17, Acinetobacter sp. strain GIB8, and Bacillus cereus strain GIB10. The results showed that the degradation rate of the bacteria increased gradually with the increase in degradation time for 60 days. Most of the MP-degrading bacteria had higher degradation rates in the presence of weak acid. The appropriate addition of Mg2+ and K+ was favorable to improve the degradation rate of MPs. Interestingly, high salt concentration inhibited the biodegradation of MPs. Results of scanning electron microscopy (SEM), atomic force microscopy (AFM), and Fourier-transform infrared spectroscopy (FTIR) indicated the degradation and surface changes of PP and PE MPs caused by candidate bacteria, which may depend on the biodegradation-related enzymes laccase and lipase. Our results indicated that these four bacterial strains may contribute to the biodegradation of MPs in the mangrove environment.

Bi-functional hydrogen tungsten bronze/carbon composite catalysts towards biomass conversion and solar water purification

We presented a novel bi-functional catalyst composed of HxWO3 and carbon composites, which exhibits excellent catalytic activity in biomass conversion and has the ability to effectively purify water via a wide range of wavelengths in the light spectrum. The HxWO3/carbon composites were effectively produced from commercially available monoclinic tungsten trioxide (WO3) and polypropylene (PP) powders to a single-step mechanochemical reaction employing high-energy ball milling. We systemically investigated how different synthesis parameters, such as rotation speed, processing duration, and ball diameter, affect the mechanochemically-induced phase transformation to either tetragonal or cubic HxWO3 during planetary ball milling. The crystal phase of HxWO3 was controllable by altering the total impact energy in the ball milling. In addition, real-time monitoring of the pressure increment inside the pot and evaluation of the evolved gas revealed the degassing behavior through the oxidative degradation of PP assisted by WO3. The CV and Rietveld analysis proved that HxWO3 exhibited significant enhancement by two orders of magnitude in the rate of H+ diffusion compared to monoclinic WO3. This enhancement would be attributed to the expansion of a mechanically-formed tunnel along the a-axis, which facilitates the migration of H+ ions. The HxWO3/carbon composites performed approximately 12-fold higher efficiency in generating soluble solids (glucose and furfural derivatives) compared to untreated WO3 through the catalytic hydrolysis of cellulose, owing to the enhanced Brønsted acidity. Moreover, the composite particles showed broad light absorption in the UV–Vis–NIR range and demonstrated a considerable enhancement of over three orders of magnitude in the photocatalytic degradation of methyl orange pollutants when exposed to NIR and visible light.

Where are we in 2024 in the development of materials for surgical treatment of pelvic organ prolapse and stress urinary incontinence?

There is a long history of implantation of absorbable and nonabsorbable materials to treat stress urinary incontinence (SUI) and pelvic organ prolapse (POP). The focus of this review is to review the development of new materials for use in the surgical management of both pelvic conditions following an unacceptable level of severe complications in the use of polypropylene mesh (PPM). We discuss current concepts relating to the development of new materials with particular reference to our experience with polyurethane mesh. Our review highlights the strategies that manufacturers and researchers are employing to improve PPM using collagen gels and stem cells, or to find alternatives. We conclude that current preclinical safety testing is inadequate, and the field requires better in vivo testing. Specifically, we highlight novel techniques demonstrating the degradation of polypropylene potentially elucidating the link between PPM degradation and induction of inflammation leading to adverse side effects. This field badly needs innovation in developing new materials and in testing these to ensure materials will benefit patients. A collaboration between materials scientists and clinicians is needed to facilitate the translation of basic research and preclinical testing into patient benefit for the treatment of SUI and POP.

New insights on the degradation of polystyrene and polypropylene by larvae of the superworm Zophobas atratus and gut bacterial consortium enrichments obtained under different culture conditions

This study aims to deepen knowledge of the biodegradation of plastics, focusing on polypropylene (PP) fabric from surgical masks and polystyrene (PS) by larvae of Zophobas atratus as well as of specialized bacterial consortia from their gut, which were obtained in different enrichment conditions (aerobic, anaerobic, presence or absence of combined nitrogen). Plastics ingested by larvae obtained in Spain did not show any signs of oxidation but only limited depolymerization, preferably from the lowest molecular weight chains. Gut microbiota composition changed as an effect of plastic feeding. Such differences were more evident in bacterial enrichment cultures, where the polymer type influenced the composition more than by culture conditions, with an increase in the presence of nitrogen-fixers in anaerobic conditions. PS and PP degradation by different enrichment cultures was confirmed under aerobic and anaerobic conditions by respirometry tests, with anaerobic conditions favouring a more active plastic degradation. In addition, exposure to selected bacterial consortia in aerobiosis induced limited surface oxidation of PS. This possibly indicates that different biochemical routes are being utilized in the anaerobic gut and in aerobic conditions to degrade the polymer.

Degradation of Polypropylene Using Fungal Enzyme As A Sustainable Approach To Management Plastic Waste

Polypropylene (PP) is a major environmental problem in Malaysia because it has been ranked the 28th highest plastic polluter in the world (at 56kg per capita per year) in 2021. Landfilling is one of the most common ways of dealing with plastic because leachate may cause increased probability of cancer and neurological impairment in humans. The use of fungi in mycoremediation makes the process eco-friendly. In addition, fungi have a vast hyphal network and broader metabolic competence. The objective of this study was to investigate fungi remediation of PP via the detection of manganese peroxidase and laccase activity in Bushnell Haas Broth (BHB). PP degradation activity was measured via the activity of laccase and manganese peroxidase at a wavelength of 450nm and 610nm, respectively. Of the 17 species of fungi isolated from the Jeram landfill, 12 species of fungi showed growth in BHB with PP as the sole carbon source. Penicillium sp. 1, Aspergillus sp., Penicillium levitum, Talaromyces louisianensis, Aspergillus tamarii, Cunninghamella bertholletiae, Penicillium sp. 2 and Aspergillus niger demonstrated high and longer laccase activity, and these fungi could be considered as potential fungi. P. levitum, P. janthinellum, Penicillium sp, and T. louisianensis have high and longer MnP activity. In summary, P. levitum and T. louisianensis have a high and long duration of MnP and laccase activity in degrading PP, which can be developed and integrated into plastic waste management.

Tenebrio molitor Larvae Feeding Strategy to Degrade Polypropylene Components from Disposable Masks

<p><strong>Abstract.</strong>The surge in mask consumption during the COVID-19 pandemic led to the widespread use of disposable polypropylene masks for protection. However, the accumulation of used masks poses environmental challenges due to the slow degradation of polypropylene. Here, we investigate the potential of <em>Tenebrio molitor</em> larvae in degrading polypropylene masks, exploiting their synthetic polymer-breaking enzymes and associated microflora. In this study, we implemented various feeding strategies and established specific feed compositions to assess <em>T. molitor</em> larvae's consumption behavior towards polypropylene masks. Over a 21-day observation period, we noted a consumption rate of 0.4% of masks, with a 7.5% mortality rate among the larvae. The average daily consumption rate was 0.201 grams, resulting in a 2.3% increase in larval weight and the production of 0.4635 grams of feces. Our findings highlight the potential of <em>T. molitor</em> larvae as effective mask degraders. Optimizing cultivation conditions and feeding strategies may further enhance microbial diversity, potentially introducing more polypropylene degraders within <em>T. molitor</em>, thereby expediting mask degradation. This study emphasizes the promising role of <em>T. molitor</em> larvae in addressing the environmental challenges posed by the accumulation of polypropylene masks.</p><p><strong>Keywords: </strong></p><p>Mask, Degrade, <em>Tenebrio molitor</em>, Microflora, Polypropylene</p>

Modeling the degradation of polypropylene and polystyrene under shock compression and mechanical cleaving using the ReaxFF force field

Polypropylene (PP) and polystyrene (PS) underwent a comprehensive investigation into their mechanical and chemical degradation through reactive molecular dynamics simulations. The simulations utilized the ReaxFF force field for CHO (carbon-hydrogen-oxygen) systems in the combustion branch. The study included equilibrium simulations to determine densities and melting temperatures, non-equilibrium simulations for stress-strain and Young moduli determination, mechanical cleaving to identify surface species resulting from material fragmentation, and shock compression simulations to elucidate chemical reactions activated by some external energy sources. The results indicate that material properties such as densities, phase transition temperatures, and Young moduli are accurately reproduced by the ReaxFF-CHO force field. The reactive dynamics analysis yielded crucial insights into the surface composition of fragmented polymers. Both polymers exhibited backbone breakage, leaving -CH2· and –CH·- radicals as terminals. PP demonstrated substantial fragmentation, while PS showed a tendency to develop crosslinks. A detailed analysis of chemical reactions resulting from increasing activation due to increasing value of compression pressure is presented and discussed.

Distribution characteristics and microbial synergistic degradation potential of polyethylene and polypropylene in freshwater estuarine sediments

The microbial degradation of polyethylene (PE) and polypropylene (PP) resins in rivers and lakes has emerged as a crucial issue in the management of microplastics. This study revealed that as the flow rate decreased longitudinally, ammonia nitrogen (NH4+-N), heavy fraction of organic carbon (HFOC), and small-size microplastics (< 1 mm) gradually accumulated in the deep and downstream estuarine sediments. Based on their surface morphology and carbonyl index, these sediments were identified as the potential hot zone for PE/PP degradation. Within the identified hot zone, concentrations of PE/PP-degrading genes, enzymes, and bacteria were significantly elevated compared to other zones, exhibiting strong intercorrelations. Analysis of niche differences revealed that the accumulation of NH4+-N and HFOC in the hot zone facilitated the synergistic coexistence of key bacteria responsible for PE/PP degradation within biofilms. The findings of this study offer a novel insight and comprehensive understanding of the distribution characteristics and synergistic degradation potential of PE/PP in natural freshwater environments.

Synergistic Effects and Kinetic Analysis in Co-Pyrolysis of Peanut Shells and Polypropylene.

The impact of COVID-19 has boosted growth in the takeaway and medical industries but has also generated a large amount of plastic waste. Peanut shells (PS) are produced in large quantities and are challenging to recycle in China. Co-pyrolysis of peanut shells (PS) and polypropylene (PP) is an effective method for processing plastic waste and energy mitigation. Thermogravimetric analysis was conducted on PS, PP, and their blends (PS-PP) at different heating rates (10, 20, 30 °C·min-1). The results illustrated that the co-pyrolysis process of PS-PP was divided into two distinct decomposition stages. The first stage (170-400 °C) was predominantly linked to PS decomposition. The second stage (400-520 °C) resulted from the combinations of PS and PP's thermal degradations, with the most contribution from PP degradation. With the increase in heating rate, thermogravimetric hysteresis appeared. Kinetic analysis indicated that the co-pyrolysis process reduced the individual pyrolysis activation energy, especially in the second stage, with a correlation coefficient (R2) generally maintained above 0.95. The multi-level reaction mechanism function model can effectively reveal the co-pyrolysis process mechanism. PS proved to be high-quality biomass for co-pyrolysis with PP, and all mixtures exhibited synergistic effects at a mixing ratio of 1:1 (PS1-PP1). This study accomplished effective waste utilization and optimized energy consumption. It holds significance in determining the interaction mechanism of mixed samples in the co-pyrolysis process.

Molecular-Weight-Dependent Degradation of Plastics: Deciphering Host-Microbiome Synergy Biodegradation of High-Purity Polypropylene Microplastics by Mealworms.

The biodegradation of polypropylene (PP), a highly persistent nonhydrolyzable polymer, by Tenebrio molitor has been confirmed using commercial PP microplastics (MPs) (Mn 26.59 and Mw 187.12 kDa). This confirmation was based on the reduction of the PP mass, change in molecular weight (MW), and a positive Δδ13C in the residual PP. A MW-dependent biodegradation mechanism was investigated using five high-purity PP MPs, classified into low (0.83 and 6.20 kDa), medium (50.40 and 108.0 kDa), and high (575.0 kDa) MW categories to access the impact of MW on the depolymerization pattern and associated gene expression of gut bacteria and the larval host. The larvae can depolymerize/biodegrade PP polymers with high MW although the consumption rate and weight losses increased, and survival rates declined with increasing PP MW. This pattern is similar to observations with polystyrene (PS) and polyethylene (PE), i.e., both Mn and Mw decreased after being fed low MW PP, while Mn and/or Mw increased after high MW PP was fed. The gut microbiota exhibited specific bacteria associations, such as Kluyvera sp. and Pediococcus sp. for high MW PP degradation, Acinetobacter sp. for medium MW PP, and Bacillus sp. alongside three other bacteria for low MW PP metabolism. In the host transcriptome, digestive enzymes and plastic degradation-related bacterial enzymes were up-regulated after feeding on PP depending on different MWs. The T. molitor host exhibited both defensive function and degradation capability during the biodegradation of plastics, with high MW PP showing a relatively negative impact on the larvae.

A Deterministic Model to Predict Tacticity Changes During Controlled Degradation of Polypropylene

Controlled degradation of polypropylene (CPP) converts high-molecular-weight (Mw) polypropylene (PP) to lower Mw PP using peroxide-induced degradation. A deterministic model is developed to predict tacticity changes in isotactic PP. The model determines instantaneous rates of defective-pentad formation and tracks accumulation of these pentads using dynamic material balances. The model relies on the assumption that lifetimes of polymeric radicals are short compared to extruder residence times. Model predictions agree with previous Monte Carlo simulations that require long simulation times. Two versions of the model are proposed: one assumes that radical migration, also called chain walking, occurs via 1–6 isomerization and one assumes 1–8 isomerization. Chain-transfer-to-polymer and chain-walking parameters are estimated using 13C NMR data obtained using initiator levels between 0.006 and 0.52 wt%. Both 1–6 and 1–8 isomerization models result in better fit to the data.

Characterization of the abiotic degradation of oxo-biodegradable polypropylene obtained from transition metal-free pro-oxidant

The pro-oxidant additives used in the production of oxo-biodegradable polymers are generally organic salts of transition metals added during the processing of polyolefins. Transition metals accelerate the photooxidation and thermal oxidation of macromolecules, producing oxygenated fragments which are then used as nutrients by microorganisms in the biodegradation process. However, the use of these additives can lead to contamination of the environment by metals, which come free from the reactions. The aim of this study was to obtain an oxo-biodegradable polypropylene by processing flat films with distinct levels of benzoin, an organic substance free of transition metals, which is biodegradable. After extrusion (t = 0 h), samples were submitted to OIT analysis, which showed that benzoin favors the thermal oxidation process. Subsequently, the samples were subjected to accelerated ageing in a UV chamber and were characterized by dilute solution viscometry (DSV), FTIR, TGA, DSC and SEM. Results of the DSV analysis revealed a significant reduction in the viscosimetric average molar mass of the samples containing the additive, which was accompanied by a considerable increase in carbonyl groups, according to the carbonyl indexes calculated from the FTIR spectra. Thermogravimetric analysis of the aged samples containing benzoin indicated a greater loss of thermal stability and the DSC thermograms revealed a considerable reduction in the melting temperature of the oxo-biodegradable PP. The SEM images of the aged samples indicated that the presence of the additive favored the appearance of regions containing flaking and erosion. In general, the results clearly indicated that benzoin accelerated the photooxidation process during ageing by UV irradiation. Unlike organic salts of transition metals, benzoin seems to act in the initiation step of photo- and thermal oxidation, as demonstrated at the end of this study.

An Investigation on the Effect of N-Hydroxyphthalimde and Supercritical Carbon Dioxide on the Peroxide Degradation of Polypropylene

The peroxide degradation of polypropylene was studied in supercritical carbon dioxide (scCO2) in the presence of a N-hydroxyphthalimide (NHPI). Six levels of NHPI concentration and 6 levels of peroxide concentration were selected and each permutation was tested both with and without scCO2. It was observed that the NHPI would increase degradation at lower peroxide concentrations (&lt;0.1 wt. %), but would suppress degradation at higher peroxide concentrations (&gt;0.2 wt. %). Furthermore, it was discovered that at an NHPI concentration of 3.3 wt. %, the stereo regularity slightly decreased with increasing peroxide concentrations.

Effect of Copper Antifouling Paint on Marine Degradation of Polypropylene: Uneven Distribution of Microdebris between Nagasaki Port and Goto Island, Japan.

Microplastics (MP) encompass not only plastic products but also paint particles. Marine microdebris, including MP, was retrieved from five sampling stations spanning Nagasaki-Goto island and was classified into six types, primarily consisting of MP (A), Si-based (B), and Cu-based (C) paint particles. Type-A particles, i.e., MP, were exceedingly small, with 74% of them having a long diameter of 25 µm or less. The vertical distribution of type C, containing cuprous oxide, exhibited no depth dependence, with its dominant size being less than 7 μm. It was considered that the presence of type C was associated with a natural phenomenon of MP loss. To clarify this, polypropylene (PP) samples containing cuprous oxide were prepared, and their accelerated degradation behavior was studied using a novel enhanced degradation method employing a sulfate ion radical as an initiator. Infrared spectroscopy revealed the formation of a copper soap compound in seawater. Scanning electron microscopy/energy-dispersive X-ray spectroscopy analysis indicated that the chemical reactions between Cl- and cuprous oxide produced Cu+ ions. The acceleration of degradation induced by the copper soap formed was studied through the changes in the number of PP chain scissions, revealing that the presence of type-C accelerated MP degradation.

Evaluation of Fenton, Photo-Fenton and Fenton-like Processes in Degradation of PE, PP, and PVC Microplastics

The global problem of microplastics in the environment is “inspiring” scientists to find environmentally friendly and economically viable methods to remove these pollutants from the environment. Advanced oxidation processes are among the most promising methods. In this work, the potential of Fenton, photo-Fenton, and Fenton-like processes for the degradation of microplastics from low-density polyethylene (LDPE), polypropylene (PP), and poly(vinyl chloride) (PVC) in water suspensions was investigated. The influence of three parameters on the efficiency of the degradation process was tested: the pH of the medium (3–7), the mass of added iron (10–50 times less than the mass of microplastics), and the mass of added H2O2 (5–25 times more than the mass of added iron). The effectiveness of the treatment was monitored by FTIR-ATR spectroscopy. After 60-min treatments, the PP microparticles were found to be insensitive. In the Fenton treatment of PVC and the photo-Fenton treatment of LDPE and PVC, changes in the FTIR spectra related to the degradation of the microplastics were observed. In these three cases, the treatment parameters were optimized. It was found that a low pH (3) and a high iron mass (optimal values were 1/12 and 1/10 of the mass of the microplastics for LDPE and PVC, respectively) favored all three. The degradation of LDPE by the photo-Fenton treatment was favored by high H2O2 concentrations (25 times higher than the mass of iron), while these concentrations were significantly lower for PVC (11 and 15 times for the Fenton and photo-Fenton treatment, respectively), suggesting that scavenging activity occurs.

Biofilm-influenced weathering of polypropylene films submerged in field samples from freshwater and marine ecosystems

Polymers in aquatic ecosystems are susceptible to degradation by natural weathering where abiotic factors and biotic factors induce changes to the physiochemical properties of the materials. The extent of plastic weathering depends on both on the material and the location, though few studies have considered the joint effects of abiotic and biotic factors present in different environments on a single plastic material. This study used microscopy, Fourier-Transform Infrared Spectroscopy (FTIR), and goniometry to evaluate biofilm growth through morphological and chemical changes of polypropylene (PP) films incubated in filtered water as a control, lake water, and ocean water. With results from the qualitative and quantitative characterizations, biofilm growth was indicated on all samples by 16 weeks. The most notable changes occurred to films immersed in ocean water as opposed to freshwater or the control. After removal of biofilm, PP degradation was also confirmed. Finally, amplicon sequencing of the 16srRNA gene on samples immersed in ocean water revealed that proteobacteria can survive on polypropylene surfaces without supplement for at least 8 weeks while PP degrades oxidatively. This work suggests that biofilm-influenced degradation can induce, and therefore accelerate polyolefin aging in the environment, especially in the presence of ocean microbial consortia.

Study on the onset mechanism of bio-blister degradation of polyolefin by diatom attachment in seawater

It is essential to develop a mechanism for lowering the molecular weight of polyolefins to achieve biodegradation in seawater. In this study, a polypropylene/polylactic acid blend sample was first subjected to photodegradation pretreatment, and it was confirmed that in pure water, the acid generated promotes the polypropylene degradation (autoxidation), while in alkaline seawater, the promotion was inhibited by a neutralization reaction. In the autoxidation of polyolefins in alkaline seawater, aqueous Cl− was also the inhibitor. However, we found that autoxidation could be initiated even in seawater by lowering the pH and using dissociation of ClOH (called blister degradation). The blister degradation mechanism enabled autoxidation, even in seawater, by taking advantage of the ability of diatoms to secrete transparent exopolymer particles (TEP) to prevent direct contact between the surface layer of polyolefins and alkaline seawater. We named blister degradation in seawater with diatoms as bio-blister degradation and confirmed its manifestation using linear low-density polyethylene (LLDPE)/starch samples by SEM, IR, DSC and GPC analysis.

Dual functionalized copper nanoparticles for thermoplastics with improved processing and mechanical properties and superior antibacterial performance.

The utilization of metal nanoparticles for antibacterial thermoplastic composites has the potential to enhance the safety of human and animal life by mitigating the spread and transmission of foodborne pathogenic bacteria. The dispersion, antioxidant and antimicrobial activities of metal nanoparticles directly affect the application performance of the composites. This study focused on achieving amine-carboxyl co-modified copper nanoparticles (Cu-AC) with excellent antioxidant properties and monodispersity through in situ grafting of amine and carboxyl groups onto the surface of copper nanoparticles via ligand interaction. Polyacrylic acid's extended carbon chain structure was utilized to improve its dispersion and antioxidant properties, and its antibacterial properties were synergistically enhanced using secondary amines. It was found that Cu-AC possesses high antibacterial properties, with a minimum inhibition concentration of 0.156 mg mL-1. Antibacterial masterbatches and their composites (polypropylene/Cu) manufactured by melt blending of polypropylene and Cu-AC exhibited excellent antibacterial rates of up to 90% and 99% at 300 ppm and 700 ppm Cu-AC, respectively. Additionally, Cu-AC bolstered the thermal degradation, processing and mechanical properties of polypropylene. The successful implementation of this product substantiates the potential applications of polypropylene/Cu composite materials across diverse industries.