This study presents an in vitro analysis of the bactericidal and cytotoxic properties of hybrid films containing nickel oxide (NiO) and nickel ferrite (NiFesub.2Osub.4) nanoparticles embedded in ...polypropylene (PP). The solvent casting method was used to synthesize films of PP, PP@NiO, and PP@NiFesub.2Osub.4, which were characterized by different spectroscopic and microscopic techniques. The X-ray diffraction (XRD) patterns confirmed that the small crystallite sizes of NiO and NiFesub.2Osub.4 NPs were maintained even after they were incorporated into the PP matrix. From the Raman scattering spectroscopy data, it was evident that there was a significant interaction between the NPs and the PP matrix. Additionally, the Scanning Electron Microscopy (SEM) analysis revealed a homogeneous dispersion of NiO and NiFesub.2Osub.4 NPs throughout the PP matrix. The incorporation of the NPs was observed to alter the surface roughness of the films; this behavior was studied by atomic force microscopy (AFM). The antibacterial properties of all films were evaluated against Pseudomonas aeruginosa (ATCCsup.®: 43636™) and Staphylococcus aureus (ATCCsup.®: 23235™), two opportunistic and nosocomial pathogens. The PP@NiO and PP@ NiFesub.2Osub.4 films showed over 90% bacterial growth inhibition for both strains. Additionally, the effects of the films on human skin cells, such as epidermal keratinocytes and dermal fibroblasts, were evaluated for cytotoxicity. The PP, PP@NiO, and PP@NiFesub.2Osub.4 films were nontoxic to human keratinocytes. Furthermore, compared to the PP film, improved biocompatibility of the PP@NiFesub.2Osub.4 film with human fibroblasts was observed. The methodology utilized in this study allows for the production of hybrid films that can inhibit the growth of Gram-positive bacteria, such as S. aureus, and Gram-negative bacteria, such as P. aeruginosa. These films have potential as coating materials to prevent bacterial proliferation on surfaces.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
In order to evaluate the effects of human umbilical cord-derived stem cells (HUMSCs) on the biocompatibility of and tissue response to a polypropylene (PP) mesh (GynemeshTM PS) implanted in rat ...vaginas, HUMSCs were isolated and characterized in vitro and then combined with GynemeshTM PS to create a tissue-engineered mesh. This tissue-engineered mesh and pure PP mesh were implanted in the submucosae of the posterior vaginal walls of rats. Mesh/tissue complexes were harvested at 1, 4 and 12 weeks after implantation. Histological evaluations including an assessment of the inflammatory reaction, neovascularization and fibrosis around the mesh fibers were performed and real-time quantitative polymerase chain reaction (RT-PCR) was used to analyze the mRNA expression of genes involved in wound healing at the tissue-mesh interface. After being seeded onto the PP mesh scaffold, HUMSCs grew and proliferated well in vitro culture. One week after implantation, the HUMSC-seeded mesh elicited a greater inflammatory response than the pure PP mesh (3.33 ± 0.21 vs. 2.63 ± 0.18, p = 0.026), while 4 and 12 weeks after implantation, the inflammatory response in the HUMSC-seeded mesh was lower than that in the unseeded mesh (p < 0.05). At 12 weeks, the HUMSC-seeded mesh induced a lower expression of matrix metalloproteinase (MMP)-1 and a higher expression of anti-inflammatory cytokine interleukin (IL)-4. HUMSCs may decrease the inflammatory response and improve the biocompatibility of a conventional synthetic mesh and may have the potential to reduce postoperative complications such as mesh exposure or erosion.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
It is difficult to enhance the char yields of polypropylene (PP) due to the preferential complete combustion. Successful formation of abundant char layer structure of PP upon flammability was ...obtained due to the synergistic effect of NiO, Alsub.2Osub.3 and activated carbon (AC). From characterization of scanning electron microscopy (SEM) and transmission electron microscopy (TEM), it was revealed that the microstructure of residual char contained large amount of carbon nanotubes. Compared to the modification of AC, NiO and Alsub.2Osub.3 alone, the combination of AC, NiO and Alsub.2Osub.3 dramatically promotes the charring ability of PP. In the case of AC and NiO, NiO plays a role of dehydrogenation, resulting in the degradation product, while AC mainly acts as carbonization promoter. The addition of Alsub.2Osub.3 results in higher dispersion and smaller particle size of NiO, leading to greater exposure of active sites of NiO and higher dehydrogenation and carbonization activity. Compared to the neat PP, the decomposition temperature of the PP modified by combined AC, NiO and Alsub.2Osub.3 was increased by 90 ℃. The yield of residual char of AC-5Ni-Al-PP reached as high as 44.6%. From the cone calorimeter test, the heat release rate per unit area (HRR) and total heat release per unit area (THR) of PP composite follows the order AC-5Ni-Al-PP < AC-10Ni-Al-PP < AC-Ni-PP < AC-15Ni-Al-PP < AC-1Ni-Al-PP. Compared to the neat PP, the peak of HRR declined by 73.8%, 72.7%, 71.3%, 67.6% and 62.5%, respectively.
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Supercritical COsub.2 (scCOsub.2) extrusion foamed high-melt-strength (HMS) polypropylene (PP) often suffers from low cell density, large cell sizes, and poor cell structure uniformity due to the ...poor nucleation rates of COsub.2 in the PP. To remedy this, various inorganic fillers have been used as heterogeneous nucleation agents. Although their efficient nucleation effects have been demonstrated, the preparation of these fillers causes some adverse effects on the environment/human health or involves relatively expensive processes or non-eco-friendly chemicals. In this work, biomass-based lignin is studied as a sustainable, lightweight, and cost-effective nucleating agent. It is found that scCOsub.2 could assist in situ dispersion of lignin in the PP in the foaming process, leading to significantly increased cell density, smaller cells, and improved cell uniformity. The Expansion Ratio is also simultaneously improved due to reduced diffusive gas loss. The PP/lignin foams with low lignin loadings exhibit higher compression moduli and plateau strengths than the PP foams with the same densities owing to the improved cell uniformity and probably also the reinforcing effect of the small lignin particles in cell walls. Moreover, the energy absorption capability of the PP/lignin foam with 1 wt% lignin could match the PP foam with similar compression plateau strengths; even the density of the former is 28% lower than the latter. Therefore, this work provides a promising approach to a cleaner and more sustainable production of HMS PP foams.
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The crystallization behavior, melting characteristics, and semicrystalline morphologies of wollastonite-filled recycled polypropylene (R-PP) composites without and with beta-nucleating agent were ...investigated in this study. The crystallization temperature (T.sub.c) of 20 mass% wollastonite-filled R-PP composite is 0.4 °C higher than that of R-PP, suggesting that the adding of wollastonite has little nucleation effect on crystallization of R-PP. However, 0.3 mass% TMB-5 significantly increases the T.sub.c of R-PP and induces a large number of beta-crystals in wollastonite-filled R-PP composites. For calcium pimelate-supported wollastonite (beta-W) filled R-PP composites, the T.sub.c and the relative beta-phase content of R-PP increase with increasing addition amount of beta-W (from 1 to 20 mass%). As a result, wollastonite-filled R-PP composites with beta-phase content higher than 85% can be obtained by adding 0.3 mass% TMB-5 or 20 mass% beta-W, which provides an effective method for realizing high value-added and low-cost recycling of R-PP.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The mechanical characteristics of hybrid polypropylene composites may be enhanced by adjusting the fibre loading and ratio, according to this study. The hot press technique was utilised to generate a ...variety of composites with four different amounts of fibre loading. In addition, the fibre ratio in composites with a 20-weight-percent fibre loading was changed. The composites were characterised using Fourier transform infrared analysis as well as tensile, flexural, and hardness tests. In the composites that have been created, Fourier transform infrared examination showed that hemicelluloses, lignins, and moisture were present, all of which have the potential to reduce tensile strength. Fibre loading resulted in a decrease in tensile strength but an increase in Young’s modulus. With increasing fibre loading, flexural modulus and hardness rose, whereas flexural strength declined. The best mechanical qualities were found in a composite made primarily of arecanut and glass fibres, with a weight ratio of 1 : 3.
This experiment was conducted to determine the growth performance, blood profile and carcass characteristics of broilers fed yellow maize stored in Polypropylene (PP) and ZeroFlyR 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 ZeroFlyR hermetic storage bags could be fed to broilers for better feed efficiency and carcass yield.
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Sargassum is a type of marine algae that has caused environmental problems in Mexico because it arrives in high quantities along the Mexican coast, especially in the Mexican Caribbean. This situation ...has become an environmental and economic problem, impacting tourism and other activities. As a result, it is reasonable to try to find an application for these algae. Recently, some applications in civil construction, cosmetics, and the food industry, among others, have been reported. The present work evaluates the thermal and structural properties of new polypropylene (PP)–Sargassum-based composites. Also, the effect of adding calcium stearate (CS) to increase the interaction between PP and Sargassum particles was investigated. PP–Sargassum particle composites were prepared by a melt mixing process, and the properties of these composites were evaluated using thermal techniques such as dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD), and infrared spectroscopy (FTIR). The DMA results showed that composites with low concentrations of Sargassum particles perform better than those with higher concentrations. When CS was added to composites, there was a significant improvement in storage modulus compared with composites without CS. This was attributed to the good adhesion of the particles to the matrix because the mobility of macromolecules increased in the presence of CS. The thermal stability of PP–Sargassum particle composites decreases when the amount of particles increases, and the addition of CS does not positively affect the thermal behavior of composites. The findings open the possibility of using Sargassum particles in new applications of these algae as a polymer additive to generate sustainable materials.
The thermal stability of nucleation effect of three highly effective beta-nucleating agents, namely an aryl diamide-based nucleating agent (TMB-5), a rare earth complex (WBG-II), and calcium pimelate ...(Ca-Pi) in isotactic polypropylene (iPP) was investigated by DSC multi-scanning cycles. All three nucleating agents induced iPP to form high contents of beta-crystals. After several thermal cycles, the relative content of beta-phase crystals (K.sub.DSC) in the nucleated iPP was decreased and the crystallization peak temperature ( Formula omitted) was also decreased. The K.sub.DSC and Formula omitted of iPP nucleated with TMB-5, WBG-II, and Ca-Pi were decreased by 0.0477, 0.1257, 0.0603, and 0.97, 2.71, 1.18 °C, respectively. It indicated that the nucleation effect became worse. The nucleation effect of TMB-5 decreased less while that of WBG-II and Ca-Pi was significantly reduced. Thus, the orders of thermal stability for nucleation effect of these three nucleating agents were TMB-5 > Ca-Pi > WBG-II.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The presented research concerns the production of foamed thermoplastic composites reinforced with natural fiber in the direction of obtaining lightweight construction materials. The purpose of the ...work was to obtain solid and porous polypropylene (PP) systems reinforced with cut basalt fiber (WB). As a foaming agent, Expancel MB930 microspheres from AkzoNobel were used, while to improve the adhesion between the fiber and the PP matrix, an additive in the form of polypropylene grafted with maleic anhydride PP-g-MA (Polybond 3200) was used. The production of composites involved mixing the ingredients by extrusion and then molding PP/WB composite in the injection process. In addition, at the injection stage, selected systems were expanded with 1.5% by weight of microspheres. The work evaluated the impact of fiber content (5, 10, 15% by weight) and its preparation as well as the impact of a compatibilizer on the properties of solid PP composites and a comparison of these properties with analogous systems with a porous structure. PP/WB materials were characterized in terms of physical and mechanical properties (density determination, static tensile and bending test); DSC and TGA thermogravimetric analysis. Foamed PP systems with fibers have better mechanical properties compared to pure PP; the addition of a compatibilizer to PP/WB composites increases the strength parameters compared to systems without its participation. Keywords: polypropylene, basalt fiber, blowing agent, composite, compatibilizer. Wytwarzano spienione kompozyty termoplastyczne wzmocnione wloknem pochodzenia naturalnego. Uzyskano lite i porowate uklady na osnowie polipropylenowej (PP) wzmocnionej cietym wloknem bazaltowym (WB). Jako srodka spieniajacego uzyto mikrosfery (Expancel MB930). W celu polepszenia adhezji miedzy wloknem a osnowa PP do ukladu dodano polipropylen szczepiony bezwodnikiem maleinowym PP-g-MA (Polybond 3200). Wytwarzanie kompozytow obejmowalo wymieszanie skladnikow w procesie wytlaczania, a nastepnie uformowanie ksztaltek kompozytow PP/WB w procesie wtryskiwania. Dodatkowo, na etapie wtryskiwania, wybrane uklady spieniano z zastosowaniem 1,5% mas. mikrosfer. Oceniono wplyw udzialu wlokna (5, 10, 15% mas.) i jego preparacji, a takze wplyw kompatybilizatora na wlasciwosci litych kompozytow PP; porownano ich wlasciwosci z cechami analogicznych ukladow o strukturze porowatej. Scharakteryzowano wlasciwosci fizyko-mechaniczne (gestosc, wytrzymalosc na statyczne rozciaganie i zginanie) materialow PP/WB, poddano je takze analizie termicznej DSC i termograwimetrycznej TGA. Stwierdzono, ze spienione uklady PP z udzialem wlokien wykazuja lepsze wlasciwosci mechaniczne niz czysty PP, a dodatek kompatybilizatora do mieszaniny poprawia charakterystyke wytrzymalosciowa otrzymanych kompozytow PP/WB. Slowa kluczowe: polipropylen, wlokno bazaltowe, porofor, kompozyt, kompatybilizator.
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