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High voltage power capacitors employ the oil-impregnated polypropylene film as the insulation. The swelling phenomenon might drive the antioxidants and small molecules within the film to migrate into the oil. It is necessary to comprehensively investigate the physical migration mechanism of antioxidants and their impact on the electrical performance of the oil-film combination insulation system and, consequently, formulate the proper selective prescription of antioxidants. Theoretical elucidation of the competitive interaction mechanism between the film and the oil in attracting antioxidant molecules was achieved through the calculation of inter-molecular binding energy, and the migration coefficient ηm was introduced to quantify the migration characteristics of antioxidants. Experimentally, the effects of antioxidants on the space charge distribution of the film, the dielectric properties of the oil, and the breakdown characteristics of both the film and oil were investigated. The experimental conclusions are consistent with theoretical analysis. The lamellar structure antioxidant molecules with ηm > 1 tend to migrate from the film to the oil, which results in increased dielectric loss and decreased breakdown strength of the insulating oil. In addition, the presence of phosphorus atoms in phosphite antioxidants contributes to a reduction in the breakdown strength of the film. For capacitor grade polypropylene film, in addition to the synergistic effect between different types of antioxidants on the thermo-oxidative stability, the structure of the antioxidant molecules and its influence on the electrical performance of the oil–film systems should also be taken into account. [ABSTRACT FROM AUTHOR]

Polypropylene (PP) has recently been actively investigated as a potential power cable insulation substitute for crosslinked polyethylene (XLPE). This is mainly due to PP's higher thermal withstand capability over XLPE. Notably, PP has much higher stiffness than XLPE and therefore needs to be modified with tougher materials to reduce its overall stiffness while maintaining its desirable dielectric properties. To date, many investigations have been conducted on the mechanical and dielectric effects of PP blended with various copolymers. Nevertheless, systematic investigations on the dielectric effects of PP blended with ethylene-based copolymers having different ethylene contents are less explored. The current work therefore reports on the impact of different ethylene contents of ethylene-based copolymers on the breakdown performances of PP. The findings reveal that PP blended with a copolymer having a low ethylene content (68.7 wt%) results in at least 11% higher breakdown performance than PP containing a copolymer having a high ethylene content (77.0 wt%). Specifically, PP containing 10 wt% of copolymers having 68.7 wt% of ethylene content results in comparable breakdown performance to XLPE (325 kV mm J). These results suggest that ethylenc-based copolymers with an appropriately low ethylene content can be blended with PP to achieve desirable breakdown properties. Highlights * PP is blended with copolymers of varying amounts and ethylene contents. * PP blended with low amounts of copolymers has good breakdown strength. * PP blended with low ethylene level copolymers has favorable breakdown strength. * PP blended with copolymers of low ethylene contents is desirable. * The breakdown mechanisms are related with the structure and permittivity. KEYWORDS breakdown, copolymer, dielectric, polymer blend, polypropylene, 1 | INTRODUCTION To date, crosslinked polyethylene (XLPE) is widely favored for insulating high voltage alternating current (HVAC) and high voltage direct current (HVDC) cables because of its outstanding dielectric [...]

This experiment was conducted to determine the growth performance, blood profile and carcass characteristics of broilers fed yellow maize stored in Polypropylene (PP) and ZeroFly[R] Hermetic (ZFH) storage bags for six months. Two hundred unsexed day-old Cobb-500 broiler chicks were randomly allocated to 2 treatments (2 storage bags) with 100 chicks per treatment in a Completely Randomized Design experiment. Each treatment had four replications with 25 birds per replicate. The experimental diets were formulated using the same quantities of maize stored in the PP and ZFH bags. The study was in three phases, that is, starter, grower and finisher phases and each had 22%, 20% and 18% crude protein (CP), respectively. The experiment lasted for six weeks. Feed and water were offered ad libitum. Statistical analyses were performed with SAS Version 9.4. Effects of storage bags were assessed using a one-way analysis of variance (ANOVA). Tukey's Honestly Significant Difference test was used as an option in the Mixed Procedure to determine differences between means (p < 0.05). Broilers on the ZFH bag dietary treatment recorded significantly (p = 0.035) higher weight gain in grams (2395.l1 [+ or -] 32.15), than their counterparts on the PP treatment (1980.30 [+ or -] 82.19). The feed conversion ratio, measured as feed: gain ratio, was better (p = 0.041) for the ZFH birds (1.74 [+ or -] 0.03) than the PP birds (2.24 [+ or -] 0.19). Birds fed the ZFH diet had higher (p < 0.05) dressing percentage (74.05 [+ or -] 0.24), percentage whole thigh (14.45 [+ or -] 0.10) and percentage drumstick (9.22 [+ or -] 0.16) than their PP counterparts. All the blood profile parameters measured were similar except total cholesterol and aspartate aminotransferase in which birds on the ZFH maize recorded higher values (p < 0.05). It was concluded that maize stored in ZeroFly[R] hermetic storage bags could be fed to broilers for better feed efficiency and carcass yield. Key words: Deltamethrin, grain storage technique, mycotoxin contamination, post-harvest loss, INTRODUCTION Undoubtedly, the two most indispensable nutrients in the diets of poultry are carbohydrates and proteins because they represent virtually 90% of the total cost of the ingredients in a [...]

Polypropylene (PP) is believed to be a rather promising cable insulating material for high‐capacity electric power system with low carbon emission due to its decent thermo‐resistance and recyclable nature. In this paper, a new dually chemical grafting modification strategy by methyl acrylate (MA) and acrylic acid (AA) is put forward to tailor the charge transportation behavior in PP, thus further enhancing the electrical properties. Experimental results indicate that the dually grafted PP with 2.3 weight percent (wt%) MA and 1.9 wt% AA shows enhanced volume resistivity and electrical breakdown strength than pure PP, and the space charge injection is significantly suppressed. This work further adopts thermally stimulated depolarization current (TSDC) test and computational analysis based on density functional theory (DFT) to reveal the mechanism of enhancement. The analysis shows that grafted chemical groups can introduce quantities of deep traps and electrostatic potential wells which are strongly correlated with the carbonyl group and would hinder the charge transportation thus improving the electrical insulating performances of PP. This work would provide a new route of PP‐based dually grafting modification for the development of high‐voltage cable insulation. [ABSTRACT FROM AUTHOR]

This study evaluated the influence of adding borosilicate residue (BS) as a flame retardant in polypropylene (PP) and natural fiber composites. The natural fibers used in this study come from the residue of the carpet industry, which is composed of PP and jute fibers (JT), while the PP used as the polymer matrix is postindustrial recycled material. The composites were produced by corotational twin‐screw extrusion and injection molding to obtain the test specimens. A coating process was carried out to add the water‐soluble fraction of BS to the surface of the compositions that did not receive it through incorporation during processing. To characterize the composites, flammability tests, thermogravimetric analysis (TGA), tensile strength test, and morphological analysis by scanning electron microscope (SEM) were performed. The addition of only 2 wt% BS content induces an increase in thermal stability of 32 and 109°C for composites with and without natural fibers, respectively. The addiction of 20 wt% BS elevates the elastic modulus up to 27% of the composites with and without natural fibers. The BS characterization indicates that it could be applied as a flame retardant when applied as coating methods using the water‐soluble fraction of BS, reducing the burning rate up to 92%. Flammability results are similar for formulations with and without natural fibers, indicating that the natural fibers did not influence the proposed flame retardant. The findings suggest that BS coating is a potential solution to improve the properties of natural fiber‐reinforced polymer composites while also promoting waste recycling. This approach produces composites with improved flammability, thermal stability, and mechanical properties, making them suitable for various end applications. [ABSTRACT FROM AUTHOR]

The dimensional accuracy of injection molded parts plays an increasingly significant role in the plastics processing industry, as is the utilization of recycled raw materials. To obtain the desired dimensions and properties of injection moldings, various material modification methods are used simultaneously. The conducted research aimed to assess the impact of hybrid modification of non-nucleated heterogeneously isotactic polypropylene using recovered phosphogypsum and a chemical blowing agent on the shrinkage value and mechanical properties of injection molded parts. Additionally, changes in dimensions and properties of composites with solid and porous structures that occur within 1000 hours of their removal from the injection mold were determined. The research showed that the filler used acts as a nucleating agent causing an increase in the shrinkage of the parts, up to 10 wt%. Similar changes were observed in the case of tensile strength. The increase in the value of this parameter at the lowest phosphogypsum contents used was most likely the result of changes in the crystalline structure of polypropylene. Changes in the mechanical properties of the molded parts that occurred during conditioning are correlated with shrinkage changes that occur from the moment the molded parts are removed from the injection mold. Young's modulus and tensile strength increased linearly for both solid and porous moldings. However, the rate of stiffness increases as a function of shrinkage changes with the filler content. Nevertheless, the opposite tendency was observed in the case of changes in impact strength, the values of which decreased as a function of shrinkage to the greatest extent in the case of unfilled polypropylene. [ABSTRACT FROM AUTHOR]

In this work, poly(4‐methyl‐1‐pentene)/polypropylene/poly(4‐methyl‐1‐pentene) tri‐layer films were prepared. The microstructure of the film was adjusted by annealing in the temperature range of 150–237.5°C. Afterward, the influence of annealing and stretching temperature on the cavitation behavior of the film was investigated by small‐angle x‐ray scattering (SAXS). Results showed that for the "butterfly" scattering in the early stage, the radius of gyration (Rg) and maximum dimension (Dmax) of voids were ca. 75 and 200 nm, which were hardly influenced by annealing. Whereas, the volume fraction of voids was enlarged obviously, suggesting that more voids were formed; for the "streak" scattering in the late stage, the length of voids (Lv) grew gradually with stretching, and the ultimate value of Lv was 432.5 nm for un‐annealed film and 176 nm for film annealed at 230°C. Simultaneously, the misorientation of voids was reduced from 0.33 to 0.18. As the stretching temperature was elevated from 30 to 45 and 60°C, Rg and Dmax maintained at 75 and 200 nm, and Lv was enlarged to 434 and 432 nm. At the same time, the number of voids was reduced obviously. As the stretching temperature was 90°C, the voids were suppressed. [ABSTRACT FROM AUTHOR]

Polypropylene double‐grafted maleic anhydride and bisphenol A epoxy resin (PP‐g‐M‐E) was successfully prepared by a single‐step method and characterized by Fourier‐transform infrared spectroscopy. Subsequently, it was employed as a compatibilizer to fabricate polypropylene (PP)/polyethylene terephthalate (PET) blends via melt extrusion. The content of the PET dispersed phase in the composite varied from 0 to 30 phr. The microstructure and morphology of the composites were characterized using scanning electron microscopy and Raman spectroscopy. The addition of PP‐g‐M‐E increased the interfacial interaction between the two phases and improved the compatibility and thermal stability of the system. In the presence of the compatibilizer, the crystallinity of the matrix phase (PP) increased, while that of the dispersed phase (PET) decreased owing to the heterogeneous nucleation effect of uniformly distributed PET. Double grafting of the PP‐g‐M‐E compatibilizer considerably enhanced the mechanical performance of the PP/PET blend system. The elongation at break of the modified sample exceeded that of the PP/PET blends by 117.55%, and the flexural and impact properties also showed considerable improvement. [ABSTRACT FROM AUTHOR]

Polypropylene (PP) has been widely researched in power cable insulation due to its excellent resistance against high temperatures and high voltages. Since PP is too stiff for power cable extrusion, elastomers have been blended with PP to improve its stiffness. Although effects of elastomers on electro‐mechanical properties of PP have been widely studied, fundamental issues governing changes in dielectric properties of PP/elastomer blends have yet to be fully understood. This paper therefore reports on the properties of PP blended with ethylene‐based elastomer (EBE) and propylene‐based elastomer (PBE) by correlating their structural, mechanical, and dielectric investigations with respect to elastomer types and contents. The results show that blending increasing amounts of EBE and PBE improves mechanical flexibility of PP, with Young's modulus reduces by 53% at 40 wt% of elastomer content. Morphology‐wise, PBE demonstrates better compatibility with PP and less disrupted crystallinity compared to EBE. Furthermore, PP/PBE has better breakdown performance over PP/EBE, albeit that their breakdown strengths reduce with increasing elastomer contents. Specifically, direct current breakdown strength of PP/PBE reduces by only 21% at 40 wt% of PBE loading compared to 31% at equivalent EBE loading. Potential mechanisms governing breakdown changes are discussed with structural, mechanical, and dielectric interpretations. [ABSTRACT FROM AUTHOR]

In composite materials consisting of silver particles and a polypropylene matrix, the silver must migrate to the surface of the materials in order to exert on antibacterial effect. Substrates with various crystal structures may have different interactions with the silver particles, which can significantly impact the antibacterial performance. The research described in this paper investigates the influence of silver particles on the crystallization behavior of materials with varying crystallinity capabilities by selecting various polypropylene-based plastics and elastomers (Homopolymer polypropylene (PPH-T03), random poly(propylene/ethylene) copolymers (PPR-YPR503 and PPR-P340R), polyolefin elastomers (VERSIFY3000 (POE-1) and VERSIFY3401 (POE-2)), and ethylene propylene diene monomer for polymers (EPDM4725 and EPDM4770)). The research results indicated that the silver only entered the amorphous regions of the PP rather than entering the crystal regions, where they can more easily migrate to the material surface, resulting in a higher antibacterial effect. Therefore, the antibacterial degree of PP-Ag was as high as 99.9%. Silver can enter the micro-crystals of both the random copolymer polypropylene, (PPR-YPR503, PPR-1) and the random copolymer polypropylene, (PPR-P340R, PPR-2,) with a stronger effect on PPR-2. More silver entered the micro-crystals of PPR-2, and it was difficult for the silver ions to migrate out of the crystalline regions to exhibit antibacterial properties. The antibacterial degree of PPR-1-Ag was higher than that of PPR-2-Ag (77.8% vs. 66.7%). Similarly, silver had a greater impact on the lamellar structure of the polyolefin elastomer (VERSIFY3401, POE-2) compared to the polyolefin elastomer (VERSIFY3000, POE-1). In comparison with POE-2-Ag, POE-1-Ag exhibited a higher antibacterial degree (79.6% vs. 57.4%). Research on the two types of ethylene propylene diene monomer (EPDM) composite materials indicated that EPDM-1 exhibited a lower Mooney viscosity and poorer flowability. The EPDM-1 tended to encapsulate the silver within its molecular chains, thereby impeding the migration of silver to the surface. The optical performance analysis indicated that silver antibacterial agents had little impact on the optical properties of PP-Ag, PPR-1, PPR-2, POE-1, POE-2 and the EPDMs. We suggest that this research provides theoretical guidance for selecting highly antibacterial polypropylene materials. [ABSTRACT FROM AUTHOR]

Thermal resistance of cold-weather clothing is achieved by layering and filling. In this study, kapok/polypropylene blended (70/30, 60/40, and 50/50) needle-punched nonwovens were manufactured with 100 and 200 g/m2 areal density. Chicken feather fibers were used as fillers for developing quilted composite structures (QCS). To produce a QCS, 100 and 200 g/m2 nonwovens were individually used as the top and bottom layers, and the middle layer was filled with chicken feather fibers in 100, 200, 350, 550, 600, and 850 g by weights. The structures were characterized for thermal properties, and it was noted that 70/30 kapok/polypropylene nonwovens in 100 g/m2 set had the highest thermal resistance between 0.5901–0.6461 °C m2/W. Thermal resistance is greatly influenced by kapok, chicken feather fiber quantity in the assembly along with the areal density (1000 g/m2) of the QCS. Results show that the developed QCS has higher thermal insulation and can be used for cold-weather apparel and sleeping bag. [ABSTRACT FROM AUTHOR]

Emerging legal requirements will likely considerably heighten demand for high-quality recycled raw materials for e.g., packaging and automotive applications; key EU legislation mandates recycling as the future end-of-life option for municipal solid plastic waste. Yet recycled plastic use remains low due to safety concerns, undesirable aesthetic, olfactory, and mechanical properties, mainly attributable to contaminants present in recyclates. Advanced treatment options for recovered polypropylene (PP) packaging and the impact of such treatments on the polymer are currently poorly documented. We investigated the effectiveness of hot/cold washing and hot air devolatilization treatments in removing volatile substances from residential post-consumer PP plastic waste to improve its scope of application and value and to assess possible side effects on mechanical and processing parameters. Cold- and hot-washed recyclates exhibited similar contaminant levels and most substances were removed within 7 h. The recycling procedure had no adverse effects on mechanical or processing parameters although reprocessing caused polymer degradation, indicated by decreasing viscosity, elongation at break, and tensile strength. Washing and hot air devolatilization treatment of plastic wastes improve their scope of application and value by enhancing mechanical properties and considerably reducing the amounts of odorous substances, but is often not suited to high-quality applications, such as packaging. The dominance of packaging waste and strict legislation on food-grade recyclate applications will make widespread recyclate use challenging since it represents the primary use of plastic. Recyclate must consequently be extensively utilized in non-food contact applications until advances in waste sorting, washing, and devolatilization yield less contaminated recyclates with improved properties. [ABSTRACT FROM AUTHOR]

The current study aims to model and optimize the catalytic pyrolysis of plastics, incorporating an agricultural biomass waste-derived catalyst. Polystyrene (PSW) and polypropylene (PPW) are experimented with thermal and catalytic pyrolysis. Agricultural biomass waste (wheat husk) was selected and acid treated with sulfuric acid (HZSM-5SA) and hydrochloric acid (HZSM-5CA), and then used as catalyst. Thermal and catalytic pyrolysis were conducted in a semi batch reactor, with reaction temperature (500 ℃) and different ratios (10:1, 10:2 & 10:3). At a ratio 10:2, PSW with HZSM-5SA produced 91.19 wt.% of oil yield and PPW with HZSM-5SA produced 85.73 wt.% of oil yield. The catalyst HZSM-5SA was effective in the reduction of reaction temperature and time, it decreased from 450 ℃ to 437 ℃ and 22 min to 14 min for PSW. Catalyst activity was also observed for PPW, the reaction temperature decreased from 471 ℃ to 456 ℃ and 34 min to 19 min. Oil properties were determined and it was found that the kinematic viscosity of oil obtained from PSW with HZSM-5SA was 2.53 cSt, which coincide with the diesel Bharat Stage (BS VI 2020). Total conversion of pyrolysis products was predicted using six Machine Learning (ML) models such as Random Forest, Support Vector, K-Nearest Neighbor, Decision Tree, AdaBoost, and Gradient Boost. Among all the models, the Gradient Boost regressor model had a good evaluation metrics of R2 value of 0.984 and RMSE of 0.019, respectively. This study illustrates the use of ML models to predict the total conversion and their correlation matrix with target and feature variables. This study also highlights that cost-effective catalyst can be prepared from biomass (wheat husk) and the use of ML models to train the datasets and evaluate the actual and predicted values. Highlights: In situ catalytic pyrolysis of PSW and PPW was experimented. HZSM-5 prepared from agricultural biomass waste (wheat husk). Enhanced liquid yield of 91.19 wt.% obtained for PSW + HZSM-5SA. 70.19 wt.% of diesel-like fractions obtained in oil yield. Machine Learning model—Gradient Boost algorithm predicted the total conversion of products with R2 0.984. [ABSTRACT FROM AUTHOR]

The automotive industry is under significant pressure to curb greenhouse gas emissions from their products as the negative impacts on the environment are increasingly apparent. As such, there is significant interest within the industry to develop low-carbon footprint materials. Natural fiber composites are therefore appealing due to both their decreased carbon footprint, as well as their relatively low cost, low density, and beneficial acoustic properties. This research specifically focuses on the use of paper fibers as composite reinforcements. Paper offers additional benefits over other natural fiber types in that it is globally available, does not compete with food resources, and has well-established quality control techniques. The goal of this work was to study the manufacturing of polypropylene (PP)-paper fiber composites using a hybrid wet-lay/compression molding processing. The processing parameters studied included molding temperature, molding duration, and molding pressure. Paper composites were characterized for properties including flexural strength, impact strength, and water uptake rate. An optimal set of processing parameters was identified in which cycle time and energy inputs (e.g. temperature and pressure) were minimized while retaining desired material properties. [ABSTRACT FROM AUTHOR]

In this work, a new compatibilizer, ternary monomer grafted polypropylene (hereafter shorted as: G‐PP), was successfully synthesized by solid phase grafting of maleic anhydride, methyl methacrylate, and butyl‐acrylate onto polypropylene. For all developed polypropylene matrix composites, the prepared G‐PP evidently showed enhancing mechanical properties on PP/wood flour (WF) composites, which is obviously superior to those from maleic anhydride grafted polypropylene (W‐PP) and virgin polypropylene (C‐PP). In particular, the wettability of G‐PP was greatly improved, while the melting temperature and β crystal phase amounts of the WF composites with G‐PP are much higher when compared to that of W‐PP and C‐PP. This can be reasonably explained by the formation of continuous micropores and filaments in WF composites containing G‐PP, as verified by hot stage polarizing optical microscope (POM). Meanwhile, the G‐PP effectively reduced movement of molecular chains of WPC and formed a better interface layer with WF, which contributed to penetrate more deeply and form micro‐crosslinking in the WF layer. We believe that the results reported in this work will increase the added value of polypropylene based wood plastics composites (WPC) and allow WPC to participate in lightweight and environmentally friendly products. [ABSTRACT FROM AUTHOR]

The present work provides a unique insight to reveal the long chain branching (LCB) influence to the nano‐fillers, that is via analyzing the conductivity evolution during the thermal annealing, fast shear flow and melt to solid cooling process. Meanwhile the crystallization behavior is also discussed. A linear polypropylene (PPC) and a long chain branched polypropylene (PPH) are chosen as the two polymer matrices with carbon nanotubes (CNTs) as the nanofillers. During the thermal annealing process, a more obvious growth of electrical conductivity of linear PPC nanocomposites are observed compared with LCB PPH nanocomposites. The harder movement of CNTs inside LCB PPH matrix may be the main reason. This also can be reflected by the conductivity evolution during slow cooling process where a decrease‐then‐increase (DTI) phenomenon is found for PPC/CNTs systems due to the rebuilding of CNTs conductivity network after crystallization. By contrast, this does not happen for PPH/CNTs systems. [ABSTRACT FROM AUTHOR]

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Polyolefins such as polyethylenes and polypropylenes are the most‐produced plastic waste globally, yet are difficult to convert into useful products due to their unreactivity. Pyrolysis is a practical method for large‐scale treatment of mixed, contaminated plastic, allowing for their conversion into industrially‐relevant petrochemicals. Metal–organic frameworks (MOFs), despite their tremendous utility in heterogeneous catalysis, have been overlooked for polyolefin depolymerization due to their perceived thermal instabilities and inability of polyethylenes and polypropylenes to penetrate their pores. Herein, we demonstrate the viability of UiO‐66 MOFs containing coordinatively‐unsaturated zirconium nodes, as effective catalysts for pyrolysis that significantly enhances the yields of valuable liquid and gas hydrocarbons, whilst halving the amounts of residual solids produced. Reactions occur on the Lewis‐acidic UiO‐66 nodes, without the need for noble metals, and yield aliphatic product distributions distinctly different from the aromatic‐rich hydrocarbons that can be obtained from zeolite catalysis. We also demonstrate the first unambiguous characterization of polyolefin penetration into UiO‐66 pores at pyrolytic temperatures, allowing access to the abundant Zr‐oxo nodes within the MOF interior for efficient C−C cleavage. Our work highlights the potential of MOFs as highly‐designable heterogeneous catalysts for depolymerisation of plastics, which can complement conventional catalysts in reactivity. [ABSTRACT FROM AUTHOR]

It is known that X‐ray CT of organic polymer materials usually provides low‐contrast images because of the low X‐ray absorption of these materials. In this paper, we describe a new method to enhance the contrast of X‐ray CT images of organic polymer materials. We demonstrate that gamma‐ray irradiation of poly (ethylene terephthalate) (PET) fibers in dichloromethane containing 2‐bromoethyl methacrylate, 2‐chloroethyl methacrylate, or 4‐bromostyrene results in the grafting of halogen‐containing oligomeric chains onto the PET fibers. Focused ion beam scanning electron microscopy (FIB‐SEM) and time‐of‐flight secondary ion mass spectrometry (TOF‐SIMS) analyses revealed a homogeneous distribution of bromine atoms within the 2‐bromoethyl methacrylate‐modified PET fibers, not only on the surface. This uniform incorporation translated to a significant improvement in X‐ray CT image contrast compared with pristine fibers. Similar treatment of polypropylene pellets also enhanced the contrast of their X‐ray CT images. This is a new simple and effective method to enhance the X‐ray CT image contrast and potentially applicable to various polymer materials including polymer composites and porous polymer materials, readily allowing the observation of their 3D microstructures finely. [ABSTRACT FROM AUTHOR]

AbstractOur 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. [ABSTRACT FROM AUTHOR]

Background: To introduce a new flange technique (called the Z.S. fixation technique) for 8 − 0 polypropylene suture in scleral fixation of a one-piece intraocular lens (IOL) and evaluate its effectiveness and safety. Methods: All surgeries were performed using two strategies. First, the Z.S. fixation technique was used to fix 8 − 0 polypropylene sutures to the sclera and the two haptics of a one-piece IOL, respectively. The one-piece IOL previously implanted in the anterior chamber was then relocated to the posterior chamber. Finally, the suture ends outside the sclera were cauterized into flanges and buried in the sclera. All effectiveness and safety data related to the Z.S. technique were recorded and compared. Results: The Z.S. fixation technique was employed in 16 eyes of 13 patients, with a follow-up duration of at least 6 months. Postoperative uncorrected distance visual acuity (UDVA) was greatly improved in most of the operated eyes (11/16). The mean log MAR UDVA after surgery was significantly improved compared with that before surgery (0.93 ± 0.72 vs. 1.53 ± 0.73, P = 0.002). IOLs in the vast majority of operated eyes (15/16) remained stable during half-year follow-up. No severe intra-/post-operative complications were observed in any of the operated eyes. Conclusion: The Z.S. fixation technique for 8 − 0 polypropylene suture in scleral fixation of one-piece IOL reduced surgical injuries and had ideal surgical effectiveness and safety. Significance: What was known: To date, most 10 − 0 polypropylene suture scleral fixation techniques required knot fixation outside the sclera, which inevitably leads to long-term complications related to 10 − 0 sutures, such as suture erosion, knot exposure, and late suture breakage. Therefore, some scholars began to use 8 − 0 polypropylene suture to perform scleral fixation for one-piece intraocular lens with specific structures, but the scope of application was very narrow. What this paper adds: We introduced a compound technique of electrocoagulation fixation and scleral flapless knotless interlaminar anchoring for 8 − 0 polypropylene suture, which can be applied to most one-piece intraocular lenses. [ABSTRACT FROM AUTHOR]

This study focuses on the development of environmentally sustainable polypropylene (PP)-based composites with the potential for biodegradability by incorporating cellulose and the oligomeric siloxane ES-40. Targeting industrial applications such as fused deposition modeling (FDM) 3D printing, ES-40 was employed as a precursor for the in situ formation of silica particles via hydrolytic polycondensation (HPC). Two HPC approaches were investigated: a preliminary reaction in a mixture of cellulose, ethanol, and water, and a direct reaction within the molten PP matrix. The composites were thoroughly characterized using rotational rheometry, optical microscopy, differential scanning calorimetry, and dynamic mechanical analysis. Both methods resulted in composites with markedly reduced crystallinity and shrinkage compared to neat PP, with the lowest shrinkage observed in blends prepared directly in the extruder. The inclusion of cellulose not only enhances the environmental profile of these composites but also paves the way for the development of PP materials with improved biodegradability, highlighting the potential of this technique for fabricating more amorphous composites from crystalline or semi-crystalline polymers for enhancing the quality and dimensional stability of FDM-printed materials. [ABSTRACT FROM AUTHOR]

The polypropylene (PP) synthesis process is crucial in the plastics industry, requiring precise control as it directly impacts the catalytic activity and the final product's performance. This study investigates the effects of trace amounts of four different mercaptans on the polymerization of propylene using a fourth-generation Ziegler–Natta (ZN) catalyst. Various concentrations of these mercaptans were tested, and results showed that their presence significantly reduced the melt flow index (MFI) of the final PP. The most notable MFI decrease occurred at 37.17 ppm of propyl mercaptan and 52.60 ppm of butyl mercaptan. Methyl and ethyl mercaptan also reduced the MFI at lower concentrations, indicating that mercaptans act as inhibitors by slowing down the polymerization process and reducing the fluidity of molten PP. The highest MFI increase was observed at lower concentrations of each mercaptan, suggesting that smaller molecular inhibitors require less concentration. This trend was also seen in the catalyst's productivity, where lower concentrations of methyl mercaptan reduced PP production more effectively than higher concentrations of butyl mercaptan. Fourier transform infrared spectroscopy (FTIR) identified interactions between the mercaptans and the ZN catalyst. Computational analysis further supported these findings, providing insights into the molecular interactions and suggesting possible inhibition mechanisms that could impact the final properties of polypropylene. [ABSTRACT FROM AUTHOR]

Smart materials react to external triggers by changing size, color, mechanical properties, or permeability. The next generation of smart materials will be able to not only recognize and react to external triggers but also to their dynamics. The only existing example of such a material is heating rate‐sensitive polymorphous cross‐linked syndiotactic polypropylene. This study presents a new principle of a heating rate‐sensitive material on the example of cross‐linked and fully amorphous quenchable semi‐crystalline polyethylene terephthalate (x‐PET). The x‐PET is stretched to high elongation above its melting temperature and constrained quenched to a fully amorphous state. Then the polymer is heated to 120–170 °C with different heating rates. Due to its heating‐rate sensitivity, x‐PET shrinks to different stabilized lengths dependent on the heating rate. The new length can be used to read out the heating rate and to specifically answer to this by mechanically switching a process. Detailed analytics of this process reveal that amorphous stretched x‐PET is starting the retraction above Tg and simultaneously stopping it by crystallization. The different rates of these processes result in the heating rate sensitivity of x‐PET. [ABSTRACT FROM AUTHOR]

Highlights The demand for polymers with antibacterial properties is increasing in food packaging industry and medical supplies. Antibacterial additives without toxic metal ion release are crucial for health and safety but still have challenges. Herein, polypropylene (PP) nanocomposite was prepared with polyaniline/graphene nanocomposite (PANI/GNP) as a green antibacterial additive due to its electrostatic, free radical, and nanoknife effect synergistic antibacterial mechanisms. To improve the dispersibility of PANI/GNP, nanosilica coating on PANI/GNP was constructed successfully with in situ condensation polymerization of epoxy functionalized ethyl orthosilicate to obtain EP‐nSiO2‐PANI/GNP. EP‐nSiO2‐PANI/GNP with a thin nanosilica coating has a significantly improved thermal stability as compared with that of PANI/GNP characterized by TGA. The EP‐nSiO2‐PANI/GNP presents a nanoscale disperse state in PP nanocomposite and thus enhances the melt viscosity and storage modulus accordingly characterized by TEM and Rheology. The EP‐nSiO2‐PANI/GNP/PP filled with 0.5 wt% of EP‐nSiO2‐PANI/GNP demonstrates antibacterial activity of 100% against both Escherichia coli and Staphylococcus aureus. In situ condensation polymerization to prepare EP‐nSiO2‐PANI/GNP. EP‐nSiO2‐PANI/GNP has enhanced dispersion stability. EP‐nSiO2‐PANI/GNP with a thin nanosilica coating has a good thermal stability. PP nanocomposite with 0.5 wt% filler has excellent antibacterial activity. The electrostatic, free radical, and nanoknife effect antibacterial mechanism. [ABSTRACT FROM AUTHOR]

In specific applications like ice-repellent coatings or membrane separation technology, wettability is a key parameter affecting the applicability of commodity polymers. This study presents a technique to fine-control the wetting properties of a hierarchically structured polypropylene surface, enabling the transition between superhydrophobic and superhydrophilic states. To demonstrate the tunability of the wetting properties of polypropylene (PP) substrate, we prepared in a consecutive way superhydrophobic (advancing contact angle (CAadv) of 152°) and superhydrophilic (CAadv of 0°) material by solvent-treatment and mild air plasma treatment. The optimal plasma treatment parameters to achieve superhydrophilic wetting behaviour, which is stable for at least one week of storage in air was also explored. Water contact angle measurement and X-ray photoelectron spectroscopy were used to monitor the time dependency of hydrophobic recovery on a hierarchically structured PP surface. With a simple model considering structural and wetting parameters, we characterized the droplet spreading behaviour of plasma-treated roughened surfaces, which exhibited superhydrophilic wetting behaviour with equilibrium CAadv of nearly 0°. The proposed model, which aligns well with experimental data, can be used to compare the droplet spreading behaviour of plasma-treated roughened surfaces. [ABSTRACT FROM AUTHOR]

Material extrusion and injection molding are prevalent in polymer processing, but wood fiber‐reinforced polymer composites offer eco‐friendly alternatives for industries like automotive, and aviation. Our study explores biocomposites using bleached chemi‐thermomechanical pulp (BCTMP) and polypropylene (PP). BCTMP is rich in cellulose and hemicellulose and quite hydrophilic, while PP's hydrophobic structure creates a disconnect to creating a composite of the two. Traditional methods add costly coupling agents like maleic anhydride polypropylene (MAPP) in an attempt to enhance the adhesion properties of wood‐plastic composites. However, it is worth noting that even in the presence of MAPP, PP maintains its high hydrophobicity and low surface energy, despite exhibiting considerable heterogeneity. Further complexity arises from the thermal degradation characteristics of BCTMP during the melting processing of PP. Our proposed method involves premixing via cryo and planetary ball milling. This boosts PP and BCTMP adhesion, enhancing dispersion quality and mechanical properties without needing coupling agents. Moreover, the premixing of BCTMP and PP forms a thermal buffer layer around BCTMP, minimizing its thermal degradation during processing. This process also ensures even distribution of BCTMP into PP, resulting in a 200% rise in Young's modulus with 30 wt% BCTMP without compromising ultimate tensile strength. Highlights: Exploration of biocomposites using bleached chemi‐thermomechanical pulp (BCTMP) and polypropylene (PP) thorough injection moldingImplementation of premixing to enhance PP/BCTMP adhesion without coupling agentsPremixing reduces thermal degradation of BCTMP, enhances dispersion, and improves mechanical propertiesAchieving a 200% increase in Young's modulus with 30% BCTMP incorporation, while maintaining ultimate tensile strength [ABSTRACT FROM AUTHOR]

Despite extensive research, the stabilization mechanism of mesomorphic isotactic polypropylene (iPP) at room temperature has not been elucidated completely. To address this issue, nanoscale structural information is indispensable. In this study, mesomorphic‐α phase transition is studied with synchrotron wide‐angle diffraction and small‐angle X‐ray scattering. It is found that during phase transition, the mobile amorphous content remained unchanged, while rigid amorphous fraction (RAF) decreased constantly, accompanied by an increase in long period. Assuming that the increase in long period is induced by the extension of the rigid amorphous coil (RAC), the thickness of RAF (RRAF) is estimated, which is found to be 2.2 nm. This value is greater than the length of b axis in α crystal cell, which can be the reason that folded‐chain iPP clusters in mesomorphic iPP cannot approach closer to form α crystal at room temperature. Besides, with RRAF, the thickness of smectic layer is estimated, which is found to be 0.9 nm. At this thickness, bulk‐free energy cannot compensate for the folded‐surface free energy, which can be the other reason that mesomorphic iPP chains cannot transit into α crystal at room temperature. The information obtained in this study is favorable for understanding the stabilization mechanism of mesomorphic iPP. [ABSTRACT FROM AUTHOR]

Membrane osmotic distillation (OD) is applied in this work for the partial dealcoholization of beer (5.2 v/v% alcohol content) to diminish its ethanol content by around 50% giving rise to a low alcohol beer. A compromise is sought between the low alcoholic degree achieved and beer sensory properties. Moreover, the feasibility of the membrane OD process intensification is studied thanks to its combination with membrane pervaporation (PV). Two successive PV stages, one hydrophobic and the other hydrophilic, allow the production of recycled water (with less than 0.5 wt% ethanol) for the membrane OD operation and bioethanol (99% ethanol) as valuable byproduct. [ABSTRACT FROM AUTHOR]

Short-fiber reinforcement is a potent approach to improving the material properties of injection-molded parts. The main consideration in such reinforced materials is to preserve the fiber length, as this is the major influence on the properties of a given composite. The aim of this work was to investigate the different influencing parameters in injection molding processing on the properties of short carbon and glass fiber-reinforced polypropylene. We investigated parameters like melt temperature and back pressure, but also machine size and pre-heating regarding their influence on the tensile properties. We found that adjustments of melt temperature and back pressure only yield small improvements in the fiber length and the tensile properties, also depending on machine size, but a pre-heating step of the granules can significantly improve the properties. [ABSTRACT FROM AUTHOR]

Polypropylene and ammonium phosphate (AP) composites were synthesized at a 25 wt% concentration. The changes in the morphological, thermal, and physical behavior of the composites were analyzed with the addition of lignosulfonate (LG) and zirconium phosphate (ZrP). Additionally, metallic zirconium was deposited onto lignosulfonate using the magnetron sputtering technique to develop polypropylene and zirconium-modified lignosulfonate (LGMod) composites. Thus, composites of PP/25AP, PP/25AP/8LG/5ZrP, and PP/25AP/8LGMod were synthesized. The synthesis involved mixing the materials in a Hake mixer, followed by compression molding. The composites were characterized by field emission scanning electron microscopy (SEM–EDS), a thermogravimetric analysis (TGA) with combustion parameters, a vertical burn test (UL-94), a thermal camera, and mechanical properties. All composites achieved a V2 rating according to UL-94 standards. The PP/25AP extinguishes flames more quickly compared to other materials, approximately 99.2% faster than PP and showed the lowest temperature variation and mass loss after burning. The PP/25AP/8LG/5ZrP composite exhibited a 7% higher rigidity and 84.5% better flame retardancy compared to pure PP. Additionally, substituting ZrP with LGMod led to a lower environmental impact and improved thermal properties, despite some mechanical disadvantages. [ABSTRACT FROM AUTHOR]

Increasing of rubber content in isotactic polypropylene/ethylene–propylene rubber (iPP/EPR) alloys can extend the applications of this kind of polyolefin. The EPR content and phase structure of isotactic polypropylene multicomponents have great effect on the viscoelasticity and mechanical properties. iPP/EPR in-reactor alloys with a high EPR content were obtained through the in situ crosslinking of EPR chains with α,ω-diene. The morphological observation results indicate that the crosslinked iPP/EPR in-reactor alloys have a good spherical shape with clean and rough external surfaces. The high EPR content is finely dispersed in the crosslinked iPP/EPR alloys in areas ranging in size from tens of nanometers to several micrometers, which implies that a sufficient crosslinking degree of EPR chains can effectively prevent their aggregation and restrict macro-phase separation. The rheological results show a clear plateau in the terminal region, which reveals an entangled polymer chain network in the crosslinked iPP/EPR alloys. The well-dispersed EPR and the bi-continuous phase structure have a great effect on the mechanical properties of the isotactic polypropylene multicomponent which were assessed. [ABSTRACT FROM AUTHOR]

The electron donors (ED) in Ziegler–Natta (Z-N) catalysis are classified as internal electron donors (IED) and external electron donors (EED), and both IED and EED are indispensable components for enhancing the catalytic reactivity and regulating the stereoregularity of polyolefinic materials in a typical industrial Z-N catalytic process. With the intensive research on ED, the Z-N catalyst performances have experienced successive progress in the last few decades. Polypropylenes (PP) as a commodity polyolefin material, especially the isotactic PP (iPP), are produced in multi-billion pounds per annum by utilization of the various IED- and EED-assisted Z-N catalysts systems. In the course of developing Z-N catalysts, the ED constitutes a key component of the content and represents a significant area of future research. In this review, we introduced a concise overview of the functions of IEDs in the generations of Z-N catalyst systems and the widely used IED types (A total of 11 different types of IEDs are encompassed within this study) that have been developed so far. In addition, we focused on the coordination modes of different IEDs in the MgCl2-supported Z-N catalyst system and analyzed the effects of different types of IEDs on the PP isotacticity, regioselectivity, hydrogen sensitivity, and briefly introduced the application of environmentally friendly rosinate and salicylate IEDs. [ABSTRACT FROM AUTHOR]

The widespread use of synthetic composite materials has raised environmental concerns due to their non-biodegradability and energy-intensive production. This paper explores the potential of natural composites, specifically flax–polypropylene, as a sustainable alternative to traditional composites for semi-structural applications. In fact, the mechanical properties of flax–polypropylene composites are similar to synthetic ones (such as those made with E-glass fibers). However, processing challenges related to fiber–matrix interaction and material degradation necessitate suited process parameters for this sustainable type of material. For this reason, this review highlights the importance of optimizing existing manufacturing processes, such as hot press molding, to better accommodate the specific characteristics of polypropylene–flax composites. By refining the parameters and techniques involved in hot press molding, researchers should overcome current limitations and fully capitalize on its potential to produce composite materials of optimal quality. Therefore, a comprehensive literature assessment was conducted to analyze the properties and processing challenges of flax–polypropylene composites. Key process parameters affecting the material's performance are identified and discussed. By optimizing process parameters for flax–polypropylene composites, it is possible to develop a sustainable and high-performance material with a reduced environmental footprint. Further research is needed to scale up production and explore different applications for this sustainable composite material. [ABSTRACT FROM AUTHOR]

Introduction: Laparoscopic repair of large para-esophageal hiatal hernias (LPHH) remains controversial. Several meta-analyses suggest hiatus reinforcement with mesh has better outcomes over cruroplasty in terms of less recurrence. The aim of this study was to evaluate the medium-term results of treating LPHH with a biosynthetic monofilament polypropylene mesh coated with titanium dioxide to enhance biocompatibility (TiO2Mesh™). Methods: A retrospective observational study, using data extracted from a prospectively collected database was performed at XXX from December 2014 to June 2023. Included participants were all patients who underwent laparoscopic repair of large (> 5 cm) type III hiatal hernia in which a TiO2Mesh™ was used. The results of the study, including clinical and radiological recurrences as well as mesh-related morbidity, were analyzed. Results: Sixty-seven patients were finally analyzed. Laparoscopic approach was attempted in all but conversion was needed in one patient because of bleeding in the lesser curvature. With a median follow-up of 41 months (and 10 losses to follow-up), 22% of radiological recurrences and 19.3% of clinical recurrences were described. Regarding complications, one patient presented morbidity associated with the mesh (mesh erosion requiring endoscopic extraction). Recurrent hernia repair was an independent factor of clinical recurrence (OR 4.57 95% CI (1.28–16.31)). Conclusion: LPHH with TiO2Mesh™ is safe and feasible with a satisfactory medium-term recurrence and a low complication rate. Prospective randomized studies are needed to establish the standard repair of LPHH. [ABSTRACT FROM AUTHOR]

A wide range of active agents, synthetic and natural agents such as essential oils, chitosan and polyphneols consisting of curcumin, gallic acid, anthocyanins, and catechins have been used in order to develop antimicrobial packaging systems, and among them, natural polyphenolic compounds, specially curcumin (Cur) has great potential due to effective biological activities in developing food packaging material. Quercetin (Quer) is also the mostly studied flavonol as a color‐changing indicator in the food industry and has been already developed as a realistic alternative for smart and active food packaging. The reason for choosing these two polyphenolic compounds is that they simultaneously possess many beneficial properties such as antioxidant, antibacterial, antiviral, antitumoral, and anti‐inflammatory effects. Additionally, the main objective of the study is to combine polypropylene (PP), which is the most preferred and cost‐effective polymer in the packaging industry, with these active ingredients, rather than using more expensive polymer types. In this context, PP‐Quer or PP‐Cur membranes, which are new experiences based on these literatures were chemically characterized by Fourier transform infrared spectroscopy, and the surface morphology of these composite membranes was characterized by scanning electron microscopy. The antibacterial response against gram‐positive (Staphylococcus aureus) and gram‐negative (Escherichia coli) bacteria species was investigated. Furthermore, the reactive oxygen species generation and anticancer activity of these composite membranes using human colorectal adenocarcinoma (HT‐29) were observed. We proposed that PP‐Quer or PP‐Cur composite membranes can be a potential candidate as active packaging material in the food industry. [ABSTRACT FROM AUTHOR]

Charge states, thermophysical and mechanical properties of polypropylene doped with zirconium oxide nanoparticles, and their changes during heat treatment at temperatures 60 °C, 100 °C, and 140 °C are studied. The methods used are thermal stimulated depolarization (TSD), scanning differential calorimetry (SDC), and mechanical life assessment. It is shown that with an increase in the concentration of the filler, the intensity of the TSD peaks increases up to 3 vol.%. A further increase in concentration leads to a decrease in the intensity of the peaks. The activation energy of charge release from traps, temperature of maximum of the peaks, and the magnitude of the accumulated charge in the traps have also maximal value at nanoparticle concentration of 3 vol.%. The study of charge characteristics of the nanocomposite with concentration of 3 vol.% after heat treatment shows that the intensity of TSD peaks, the temperature of peak maxima, and the activation energy of charge release increase with increasing pretreatment temperature. The magnitude of the charge accumulated in traps has a maximal value at treatment temperature of 140 °C owing to the increase in the number of traps. The melting point of the composite is 149.38 °C and shifts to 146.88 °C after heat treatment at 140 °C. It indicates that the high temperature of heat treatment leads to partial destruction of polymer chains, leading to a decrease in the critical melting temperature. The mechanical durability of PP + 3%ZrO2 nanocomposite decreases with increase in pretreatment temperature. [ABSTRACT FROM AUTHOR]

To create woven bag packaging for Nitrogen-Phosphorus-Potassium (NPK) fertilizer granules, this work conducted an experimental study on the utilization of recycled polypropylene (RPP) in stretched polypropylene (PP) tapes. By altering the amount of RPP using an industrial-scale stretching tapes extrusion technique, the as-obtained RPP granules were utilized to develop three stretched tape composite series filled with 0.9, 2.8, and 3.6 wt% of RPP, respectively. The series of produced composites were described in terms of their structural, rheological, mechanical, and thermal characteristics. It was found that the inclusion of RPP into PP stretched tape composites improved the composites' rigidity but reduced their toughness, due to the cumulative legacy effect of calcite particles and the RPP oxidative effect from the reprocessing history. However, RPP has shown good results in terms of storage modulus and strain at break, hence can be utilized in textile and engineering applications. [ABSTRACT FROM AUTHOR]

Abdominal hernia surgeries are commonly performed with many different approaches, and mesh utilization has become a cornerstone in hernia repair, ensuring durable outcomes with minimal recurrence risk. However, managing contaminated hernia repairs presents unique challenges due to the heightened risks of mesh infection. Recent advancements in lightweight macroporous polypropylene meshes offer promising solutions. Studies have highlighted the superiority of macroporous polypropylene meshes compared to primary suture repair and other mesh types in terms of reduced surgical site infection rates and lower hernia recurrence rates. Moreover, utilizing macroporous polypropylene mesh in the retrorectus plane is associated with a favorable salvage rate, underscoring its efficacy in contaminated hernia repairs. At the same time, contrary evidence suggests higher postoperative complications with mesh use in settings of cleancontaminated or contaminated fields. Most significant complications are increased infection rates and similar recurrence rates compared to mesh-free repairs. New synthetic mesh that is being marketed as having better outcomes than other types of mesh and potentially primary repair need to be carefully assessed as biologic mesh once used to also be touted as the mesh to use in such fields, but more research is showing higher complication rates. The risk of infection and consequent morbidity might outweigh the benefit of less recurrence risk with mesh use. Further research, including prospective studies with long-term follow-up, is warranted to elucidate optimal hernia repair strategies in contaminated fields and inform evidence-based practice guidelines. [ABSTRACT FROM AUTHOR]

A new line of research is introduced in this study, where polypropylene face masks have been used as an additive in concrete mixtures after their treatment with a silane coupling agent (SCA). Face masks were added to concrete in 3 wt.% and 5 wt.% ratios of the weight of cement. The influence of face mask fibers on fresh, mechanical, and durability properties of concrete, along with their morphological and synergistic effect, was investigated by running the slump, compressive strength, water absorption tests, and scanning electron microscopy (SEM) and attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) analyses. The results revealed that the incorporation of untreated face masks in concrete reduced the presence of calcium silicate hydrates (C–S–H) gel in the mixture, with the development of noticeable microcracks and poor bonding between polypropylene fibers and the cementitious matrix. A maximum reduction of 64% in compressive strength and a maximum increase of 65% in water absorption was observed when 5 wt.% untreated face masks were added to concrete. However, treating face masks with SCA mitigated the adverse effect of polypropylene fibers on concrete by increasing the bond between them and the cementitious matrix. Moreover, the negative effect of face masks on concrete's strength and water absorption has diminished by 66% and 14%, respectively, when treating them with SCA. [ABSTRACT FROM AUTHOR]

With the introduction of Ce(OH) 3 , the composite electrolyte layer coating on the PP separator provides a variety of Li-ion transport channels. Coupling with LiFePO 4 (LFP) cathode and Li metal, the cells exhibit long-term cycling stability and highly capacity retention of 91.6 % after 400 cycles. [Display omitted] • The Ce(OH) 3 composite with LLZTO provides multiple effective transport channels for the uniform distribution of Li ions. • Three dimensional of Li+ transport network in the composite electrolyte layer on the PP separator. • LLZTCO@PP exhibits elevated ionic conductivity (>10– 3 S cm– 1) at room temperature, a broad electrochemical window (>4.8 V) and high lithium ion transference number of 0.73. • The cells using LLZTCO@PP exhibit a dendrite-free morphology during repeated discharge–charge, remarkable cycling stability and capacity retention. Lithium (Li) metal anodes (LMAs) are regarded as leading technology for advanced-generation batteries due to their high theoretical capacity and favorable redox potential. However, the practical integration of LMAs into high-energy rechargeable batteries is hindered by the challenge of Li dendrite growth. In this work, nanoparticles of Li 6.4 La 3 Zr 1.4 Ta 0.6 O 12 (LLZTO) loaded with Ce(OH) 3 (LLZTCO) were designed and synthesized by a hydrothermal method. A functional composite separator was crafted by coating one side of a polypropylene (PP) separator with a composite electrolyte comprised of polyvinylidene fluoride (PVDF) and LLZTCO. The synergistic interactions between PVDF and LLZTCO provide numerous rapid lithium-ion (Li+) channels, facilitating the efficient redistribution of disparate Li+ flux originating from the insulated PP separator. The composite separator demonstrated an ionic conductivity (σ) of 3.68 × 10–3 S cm−1, substantial Li+ transference number (t+) of 0.73, and a high electrochemical window of 4.8 V at 25℃. Furthermore, the Li/LLZTCO@PP/Li symmetric cells demonstrated stable cycling for over 2000 h without significant dendrite formation. The Li/LiFePO 4 (LFP) cells assembled with LLZTCO@PP separators exhibited a capacity retention of 91.6 % after 400 cycles at 1C. This study offers a practical approach to fabricating composite separators with enhanced safety and superior electrochemical performance. [ABSTRACT FROM AUTHOR]

Reintroducing recycled plastics into production processes can lead to irreversible degradation and changes in their properties, thereby limiting their recycling potential to a finite number of loops. This study investigates the impact of process-induced degradation resulting from multiple reprocessing cycles on specific material properties and aims to establish structure–property relationships. Four different polyolefins, including two polypropylenes, high-density polyethylene, and low-density polyethylene, were selected for the study. The materials underwent extrusion, pelletizing, injection molding, and milling before being reintroduced into the reprocessing cycle. This sequence of processing steps was repeated six times on each material. Various characterization techniques, including high-temperature gel permeation chromatography, melt mass flow rate, parallel-plate rheology, differential scanning calorimetry, gas chromatography–mass spectrometry, and optical defect control system, were performed to evaluate the molecular structure, rheological behavior, thermal stability, and the resulting contaminants and defects after each reprocessing step. The reprocessing of polypropylene resulted in a gradual decrease in the average molecular weights accompanied by a shift to lower viscosities and higher melt mass flow rates, whereas the polyethylene grades showed the opposite trend with a less pronounced effect in high-density polyethylene. The volatile organic compounds rose in polypropylene and sank in polyethylene after reprocessing. Additionally, all four materials exhibited an increase in degradation-related defects based on optical defect analysis. [ABSTRACT FROM AUTHOR]

The increasing awareness of the potential health risks associated with microplastics' (MPs) and nanoplastics' (NPs) presence in the environment has led to a significant rise in research focused on these particles over the past few years. This review focuses on the research on MPs'/NPs' presence and spread, pathways of exposure, toxicological effects on human health and legal framework related to MP/NP challenges. Several research projects have aimed to assess their potential harm to human health, focusing on different systems and organs. After exposure (independent of the pathway), these hazards reach the blood stream and concentrate in different organs. Further, they are responsible for harmful changes, having an immediate effect (pain, inflammation, or hormone imbalance) or lead to a long-term disease (e.g., infertility, chronic obstructive pulmonary disease, or cancer). Toxicological effects have been noticed at high concentrations of MPs, specifically polystyrene, the most widespread typical MP, but only short-term effects have been mostly studied. Significant quantities of consumed MPs have been discovered to have diverse detrimental effects, posing a threat to human welfare. The exact concentrations of microplastics that are inhaled and swallowed and then build up in the human body are still not known. Further investigation is necessary to evaluate the impact of MP/NP contamination at minimal concentrations and for prolonged durations. [ABSTRACT FROM AUTHOR]

Nowadays, synthetic polymer (plastic) particles are ubiquitous in the environment. It is known that for several decades microplastics (MPs) have been accumulating in the World Ocean, becoming available to a large variety of marine organisms. Particularly alarming is the accumulation of aging plastic particles, as the degradation processes of such particles increase their toxicity. The diverse display of negative properties of aging MPs and its effect on biota are still poorly understood. In this study, in vitro experiments modeling the interaction of pristine and UV-irradiated aging polypropylene (PP) fragments with hemocytes and mitochondria of bivalve mollusks Mytilus sp. were performed. The appearance of free radicals in the environment was recorded by spectral characteristics of indicator dyes—methylene blue (MB) and nitroblue tetrazolium (NBT). It was found that due to photooxidation, aging PP fragments sorbed more than threefold MB on their modified surface compared to pristine samples of this polymer. Using NBT, the formation of reactive oxygen species in seawater in the presence of pristine and photoactivated PP was recorded. It was also found that photodegraded PP fragments largely stimulated the development of lipid peroxidation processes in mitochondrial membranes and reduced the stability of hemocyte lysosome membranes compared to pristine PP fragments. In general, the results obtained concretize and supplement with experimental data the previously stated hypothesis of toxicity of aging MPs. [ABSTRACT FROM AUTHOR]

The heat transfer surfaces of heat exchangers are usually made of metals which may suffer from severe corrosion. When corrosive fluids are present, highly corrosion-resistant metals, graphite or ceramics are used, resulting in high costs. This study presents measured data on the thermophysical and mechanical properties of recently developed corrosion-resistant polymer composite tubes for use in heat exchangers. Extruded polymer composite tubes based on polypropylene or polyphenylene sulfide filled with graphite flakes were investigated. The anisotropic thermal conductivities of the polymer composite tubes were measured at various temperatures. The through-wall thermal conductivity of the tubes made of polypropylene filled with 50 vol.% graphite is increased by a factor of 30 compared to pure polypropylene, resulting in a thermal conductivity of 6.5 W/(m K) at 25 °C. The tubes composed of polyphenylene sulfide filled with 50 vol.% graphite have a through-wall thermal conductivity of 4.5 W/(m K) at 25 °C. The mechanical properties of the polymer composites were measured using tensile and flexural tests at different temperatures. The composite materials are more rigid and keep their mechanical properties up to a higher temperature level compared to the unfilled polymers. Surface roughness measurements show the very smooth and sealed surface of the composite tubes. The results contribute to establishing the viability of using polymer composites for heat exchanger applications with corrosive fluids. [ABSTRACT FROM AUTHOR]

The integration of natural fibre thermoplastic composites, particularly those combining flax fibres with polypropylene, offers a promising alternative to traditional synthetic composites, emphasising sustainability in composite materials. This study investigates the mechanical properties of flax/polypropylene composites manufactured using flashlamp automated tape placement and press consolidation, individually and in combination. Tensile, compression, three-point bending, and double cantilever beam tests are utilised for comparing these manufacturing processes and the mechanical performance of the resulting composites. The microstructure of the tapes is investigated using cross-sectional microscopy, and the thermophysical behaviour is analysed utilising thermogravimetric analysis and differential scanning calorimetry. The temperature during placement is monitored using an infrared camera, and the pressure is mapped with pressure-sensitive films. The natural fibre tapes show a good aptitude for being manufactured with automated tape placement. The tensile performance of tapes manufactured with automated tape placement is close to that of press consolidated samples. Compression, flexural properties, and the mode I fracture toughness critical energy release rate all benefit from a second consolidation step. [ABSTRACT FROM AUTHOR]

Microplastics (MPs) are a potential threat to the marine environment and its associated ecosystem functions. Earlier investigations revealed that the microbiome plays a crucial role in deciding the fate of MPs in the environment. Further studies also highlighted the influences of environment and polymer types on the plastisphere microbiome. Nevertheless, the major factor that determines the plastisphere microbiome remains elusive. Thus, we examined the publicly available marine plastisphere data generated from polyethylene (PE), polypropylene (PP), and polystyrene (PS), collected from three different locations to identify the importance of environment and/or polymer types in shaping the microbiome. The beta diversity analyses showed a clear distinction between samples collected from different locations. The PERMANOVA results illustrated a significant influence of environment and sample type (control/PE/PP/PS) on the microbial communities. However, the influence of sample type on microbial diversity was not significant (P-value > 0.05) when the control samples were removed from the dataset but the environment remained a significant factor (P-value < 0.05). Further, the differential abundance analyses explicitly showed the abundance of many bacterial taxa to be significantly influenced (adjusted P-value < 0.05) by the locations rather than the polymer types. The validation analysis also supports the findings. Thus, this study suggests that both the surrounding environment and polymer types determine the microbial communities on marine MPs, but the role of the environment in shaping the microbial composition is greater than that of polymer types. [ABSTRACT FROM AUTHOR]

In order to improve the strength and brittleness of ceramsite concrete, polypropylene fiber was added to ceramsite concrete in this study. A total of 180 polypropylene fiber-reinforced ceramsite concrete specimens were prepared, and cube compressive test, splitting tensile test, axial compressive test and elastic modulus test were carried out. The results show that polypropylene fiber can effectively improve the splitting tensile strength and tension-compression ratio of ceramsite concrete, and has little effect on compressive strength and elastic modulus. Based on the experimental results, the conversion relationship model between splitting tensile strength and cube compressive strength, axial compressive strength and cube compressive strength, and the numerical model of elastic modulus of polypropylene fiber-reinforced ceramsite concrete were proposed. [ABSTRACT FROM AUTHOR]

The rapid accumulation of polymer waste presents a significant environmental challenge, necessitating innovative waste management and resource recovery strategies. This study investigates the potential of chemical recycling via pyrolysis of plastic waste, specifically polystyrene (PS) and polypropylene (PP), to produce high-quality pyrolytic oils (WPPOs) for use as alternative fuels. The physicochemical properties of these oils were analyzed, and their performance in a gas turbine engine was evaluated. The results show that WPPOs increase NOx emissions by 61% for PSO and 26% for PPO, while CO emissions rise by 25% for PSO. Exhaust gas temperatures increase by 12.2% for PSO and 8.7% for PPO. Thrust-specific fuel consumption (TSFC) decreases by 13.8% for PPO, with negligible changes for PSO. The environmental-economic analysis indicates that using WPPO results in a 68.2% increase in environmental impact for PS100 and 64% for PP100, with energy emission indexes rising by 101% for PS100 and 57.8% for PP100, compared to JET A. Although WPPO reduces fuel costs by 15%, it significantly elevates emissions of CO2, CO, and NOx. This research advances the understanding of integrating waste plastic pyrolysis into energy systems, promoting a circular economy while balancing environmental challenges. [ABSTRACT FROM AUTHOR]

In this paper, the surface morphology of the parts was improved by the in‐mold decoration and microcellular foaming injection molding (MIM‐IMD), and the mechanical properties of the parts were improved by inorganic particles modification. The effects of different inorganic particles (CaCO3, MMT, Talc) on the rheological behavior, crystallization properties, cell structure, surface quality, and mechanical properties of the MIM‐IMD composites were analyzed through experimental research and comprehensive macro and micro characterization. It was found that the foamed composite added with MMT had the highest surface quality, the best cell structure, the minimum average cell diameter of 78.4 μm and the maximum cell density of 3.09 × 106 cells/cm3. Talc improved the crystallinity of polypropylene (PP) matrix, and the resulting mechanical properties were the most significant improvement. Tensile, flexural, and impact strength were increased by 20.3%, 11.6%, and 45.2%, respectively. Highlights: The MIM‐IMD process was used to improve the surface quality of the samples.The enhancement of different inorganic particles on the properties were compared.The properties were evaluated by macro‐ and micro‐characterization.Inorganic particles can significantly improve the cell structure.Inorganic particles can greatly improve mechanical properties. [ABSTRACT FROM AUTHOR]