scholarly journals Polyolefin/ZnO Composites Prepared by Melt Processing

Molecules ◽  
2019 ◽  
Vol 24 (13) ◽  
pp. 2432
Author(s):  
Alojz Anžlovar ◽  
Mateja Primožič ◽  
Iztok Švab ◽  
Maja Leitgeb ◽  
Željko Knez ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Antibacterial Activity ◽  
Color Change ◽  
Antibacterial Properties ◽  
Melt Processing ◽  
Degree Of Crystallinity ◽  
Mechanical And Thermal Properties ◽  
Nano Zno ◽  
Color Changes ◽  
Zno Powders

Composites of polyolefin matrices (HDPE and PP) were prepared by melt processing using two commercially available nano ZnO powders (Zinkoxyd aktiv and Zano 20). The mechanical and thermal properties, UV-Vis stability, and antibacterial activity of composites were studied. Tensile testing revealed that both nano ZnO types have no particular effect on the mechanical properties of HDPE composites, while some positive trends are observed for the PP-based composites, but only when Zano 20 was used as a nanofiller. Minimal changes in mechanical properties of composites are supported by an almost unaffected degree of crystallinity of polymer matrix. All polyolefin/ZnO composites exposed to artificial sunlight for 8–10 weeks show more pronounced color change than pure matrices. This effect is more evident for the HDPE than for the PP based composites. Color change also depends on the ZnO concentration and type; composites with Zano 20 show more intense color changes than those prepared with Zinkoxyd aktiv. Results of the antibacterial properties study show very high activity of polyolefin/ZnO composites against Staphylococcus aureus regardless of the ZnO surface modification, while antibacterial activity against Escherichia coli shows only the composites prepared with unmodified ZnO. This phenomenon is explained by different membrane structure of gram-positive (S. aureus) and gram-negative (E. coli) bacteria.

Ca-Doped mesoporous SiO2/dental resin composites with enhanced mechanical properties, bioactivity and antibacterial properties

2018 ◽  
Vol 6 (3) ◽  
pp. 477-486 ◽  
Author(s):  
Yu Zhang ◽  
Cui Huang ◽  
Jiang Chang
Keyword(s):  
Mechanical Properties ◽  
Antibacterial Activity ◽  
Antibacterial Properties ◽  
Resin Composites ◽  
Dental Resin ◽  
Dental Resin Composites ◽  
Mesoporous Sio2

MCS containing resin composites possess enhanced mechanical properties and antibacterial activity, and can smartly induce the deposition of apatite minerals.

Preparation and study on the optical, mechanical, and antibacterial properties of polylactic acid/ZnO/TiO2 shared nanocomposites

2020 ◽  
Vol 36 (3) ◽  
pp. 285-311
Author(s):  
Ali Tajdari ◽  
Amir Babaei ◽  
Alireza Goudarzi ◽  
Razie Partovi
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Antibacterial Activity ◽  
Optical Properties ◽  
Polylactic Acid ◽  
Field Emission ◽  
Antibacterial Properties ◽  
Hydrolytic Degradation ◽  
Scanning Electron

In this research, first, ZnO nanorods were synthesized by hydrothermal method and characterized in terms of morphological and structural properties by means of field emission scanning electron microscopy, Fourier transform infrared, and X-ray diffraction techniques. Subsequently, polylactic acid/ZnO, polylactic acid/TiO2, and polylactic acid/ZnO/TiO2 nanocomposites with different percentages of nanoparticles and two different types of ZnO morphologies were prepared and their microstructural, optical, mechanical, hydrolytic degradation, and antibacterial properties were investigated. Field emission scanning electron microscopy results of polylactic acid/ZnO and polylactic acid/TiO2 samples showed a proper dispersion and nanoparticle distribution for low percentages (up to 5 wt%) and increased aggregation for the higher percentages. Besides, a large increase in the aggregation tendency was observed for combined nanoparticles (polylactic acid/ZnO/TiO2 nanocomposites). Results of the tensile test, the UV–Vis absorption tests, and the hydrolytic degradation tests of the samples showed an enhanced mechanical (approximately 55% increase in the presence of 3–5 wt% of nanoparticles) and light absorption and degradation (approximately 85% increase in the presence of 3–10 wt% of nanoparticles) for the polylactic acid by incorporating nanoparticles. It was also observed that, in addition to the quality of dispersion and distribution of nanoparticles in the polymeric matrix, the type of morphology of nanoparticles can contribute to the improvement of these properties. The cylindrical morphology of ZnO played a greater role on improving the polylactic acid mechanical properties compared to the spherical ZnO morphology (approximately 20%). On the contrary, the increased polylactic acid optical properties and degradation with ZnO spherical morphology were more pronounced (approximately 60%). Interestingly, when both ZnO and TiO2 were added, a synergistic effect in the case of UV-shielding and degradation rate and alternatively, a detrimental effect on the mechanical properties were detected. (The polylactic acid optical properties increased by about 17% and its degradation more than doubled.) Furthermore, the antibacterial activity of polylactic acid was investigated against the two Gram-positive Listeria monocytogenes and Gram-negative bacteria Escherichia coli by incorporating nanoparticles. The results indicated that as the nanoparticle percentage increases, the antibacterial activity steadily increases.

Effect of banana fibers and plasticizer on melt processing of poly(vinyl alcohol)

2017 ◽  
Vol 37 (4) ◽  
pp. 335-343 ◽  
Author(s):  
Yottha Srithep ◽  
Dutchanee Pholharn ◽  
Onpreeya Veang-in ◽  
Suphan Yangyuen
Keyword(s):  
Mechanical Properties ◽  
Crystallization Temperature ◽  
Vinyl Alcohol ◽  
Tensile Modulus ◽  
Melt Processing ◽  
Water Soluble ◽  
Poly Vinyl Alcohol ◽  
Mechanical And Thermal Properties ◽  
Melt Blending ◽  
Banana Fibers

Abstract Poly(vinyl alcohol) (PVOH) resin is one of the most widely used water-soluble biodegradable polymer. Because of thermal degradation, PVOH exhibits limited melt processing and lacks moldability. The effects of adding glycerol as plasticizer and banana fibers (BF) to PVOH on its moldability and mechanical property were investigated. Melt blending of PVOH with glycerol and/or BF was performed in an internal mixer. The blended materials were then compression molded to produce tensile specimens. Various characterization techniques were employed to study the mechanical properties, compatibility, and crystallization behavior of the PVOH blends. By melt blending with glycerol, PVOH could be processed but decreased the tensile modulus, tensile strength, and crystallization temperature. Furthermore, the addition of BF enhanced the mechanical and thermal properties and crystallization temperature of plasticized PVOH due to compatibility between the two components. Apart from enhancing the mechanical properties and thermal stability, the incorporation of BF can reduce the production cost.

Mechanical and Thermal Properties of PLA Melt Blended with High Molecular Weight PEG Modified with Peroxide and Organo-Clay

2017 ◽  
Vol 751 ◽  
pp. 337-343 ◽  
Author(s):  
Chanchai Thongpina ◽  
Chaiwat Tippuwanan ◽  
Kwanchai Buaksuntear ◽  
Teerani Chuawittayawuta
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Molecular Weight ◽  
High Molecular Weight ◽  
Mechanical Performance ◽  
Organic Peroxide ◽  
Degree Of Crystallinity ◽  
Poly Lactic Acid ◽  
Mechanical And Thermal Properties ◽  
Cloisite 30B

The thermal and mechanical properties of poly (lactic acid) blended with high molecular weight PEG, i.e. PEG1000 and PEG6000 were compared. The contents of PEG added were 10, 12.5 and 15 % by weight, with respect to PLA. The PLA/PEG blends were modified by addition of organic peroxide in order to induced crosslinking. Addition of organic modified montmorrillonite (Cloisite 30B, C30B) was also performed in order to modify mechanical performance of PLA/PEG blends. C30B was prepared via master batch in PLA. Morphology, crystallization, thermal stability and mechanical properties of the blends were investigated using SEM, DSC, TGA and universal testing macine, respectively. Morphology of cryogenic fracture surface showed smooth brittle surface. PEG1000 well plasticized PLA where as PEG6000 shows better thermal stability and mechanical properties. The presence of PEG induced PLA to perform cold crystallization. Tm in PLA was slightly changed whereas degree of crystallinity of PLA was improved by PEG but slightly decreased by peroxide. The thermal stability of PLA was enhanced with the addtion of PEG6000. The toughening of PLA was confirmed by the increment of elongation at break. The exfoliation of C30B was interfered by the crosslink PLA. Then tensile strength of PLA/PEG/C30B/Luperox101 was then suppressed. The optimum properties, in term of toughening and thermal stability, were found at PEG content of 10 % rather than 15% by weight, for both PEG1000 and PEG6000.

scholarly journals Utilization Of Sugarcane Bagasse Cellulose-Clay Nanocomposite As A Biodegradable And Antibacterial Packaging Material To Extend The Food's Shelf Life

Khazanah ◽  
2020 ◽  
Vol 12 (2) ◽  
Author(s):  
Nadya Fitriani Pitaloka ◽  
◽  
Ardilla Sriwijayanti ◽  
Santi Anisa ◽  
Irne Dyah Ayu Wijayanti ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Antibacterial Activity ◽  
Water Vapor ◽  
Shelf Life ◽  
Sugarcane Bagasse ◽  
Toxicity Test ◽  
Nanocomposite Film ◽  
Food Packaging ◽  
Antibacterial Properties ◽  
Vapor Permeability

Food packaging materials derived from fossil fuels are single-use products that harm the health of living things when disposed of by releasing toxic byproducts. Many communities are starting to be more environmentally friendly by using biopolymers. However, some biopolymers do not have antibacterial properties, thus shortening the food’s shelf life and not applicable in food packaging. Therefore, the purpose of this work is to develop a biodegradable and antimicrobial food packaging from sugarcane bagasse and clay that degrades over time without compromising the food’s shelf life. Cellulose acetate butyrate (cab) was prepared in an amimcl ionic liquid system from sugarcane bagasse. Then the cab was plasticized using peg, resulting a film. Besides, montmorillonite (mmt) clay was modified with aryl ammonium cations using a cation exchange technique to form bmmt. The nanocomposite film was prepared by mixing the plasticized cab and bmmt, then heated at 50c to evaporate the solution. The nanocomposite film was obtained as a prototype of food packaging. Several tests were conducted including mechanical properties, water vapor permeability (wvp), antimicrobial and toxicity test. Based on research by saha et.al, 2008, the nanocomposite film with the cag, peg and bmmt 100:20:3 composition gave the best mechanical properties because of the agglomeration of bmmt. Also, the nanocomposite film had promising wvp properties as a plastic because the clay layers reduced the water vapor diffusion across the polymer matrix. The toxicity test showed that this nanocomposite film was compatible in human blood. Lastly, this nanocomposite film has antibacterial activity against b. Subtilis and p. Cepacia because of the bmmt presence. In conclusion, the nanocomposite film from sugarcane bagasse and clay containing cag, peg and bmmt 100:20:3 is a promising material for a biodegradable and antimicrobial food packaging, because it has sufficient mechanical properties, antibacterial activity, low wvp and is non-toxic.

scholarly journals Polyethylene Films Containing Plant Extracts in the Polymer Matrix as Antibacterial and Antiviral Materials

2021 ◽  
Vol 22 (24) ◽  
pp. 13438
Author(s):  
Magdalena Ordon ◽  
Magdalena Zdanowicz ◽  
Paweł Nawrotek ◽  
Xymena Stachurska ◽  
Małgorzata Mizielińska
Keyword(s):  
Mechanical Properties ◽  
Pseudomonas Syringae ◽  
Polymer Matrix ◽  
Food Packaging ◽  
Antibacterial Properties ◽  
Barrier Properties ◽  
Antiviral Effect ◽  
Extrusion Process ◽  
Mechanical And Thermal Properties ◽  
Bacterial Strains

Low density polyethylene (LDPE) films covered with active coatings containing mixtures of rosemary, raspberry, and pomegranate CO2 extracts were found to be active against selected bacterial strains that may extend the shelf life of food products. The coatings also offer antiviral activity, due to their influence on the activity of Φ6 bacteriophage, selected as a surrogate for SARS-CoV-2 particles. The mixture of these extracts could be incorporated into a polymer matrix to obtain a foil with antibacterial and antiviral properties. The initial goal of this work was to obtain active LDPE films containing a mixture of CO2 extracts of the aforementioned plants, incorporated into an LDPE matrix via an extrusion process. The second aim of this study was to demonstrate the antibacterial properties of the active films against Gram-positive and Gram-negative bacteria, and to determine the antiviral effect of the modified material on Φ6 bacteriophage. In addition, an analysis was made on the influence of the active mixture on the polymer physicochemical features, e.g., mechanical and thermal properties, as well as its color and transparency. The results of this research indicated that the LDPE film containing a mixture of raspberry, rosemary, and pomegranate CO2 extracts incorporated into an LDPE matrix inhibited the growth of Staphylococcus aureus. This film was also found to be active against Bacillus subtilis. This modified film did not inhibit the growth of Escherichia coli and Pseudomonas syringae cells; however, their number decreased significantly. The LDPE active film was also found to be active against Φ6 particles, meaning that the film had antiviral properties. The incorporation of the mixture of CO2 extracts into the polymer matrix affected its mechanical properties. It was observed that parameters describing mechanical properties decreased, although did not affect the transition of LDPE significantly. Additionally, the modified film exhibited barrier properties towards UV radiation. Modified PE/CO2 extracts films could be applied as a functional food packaging material with antibacterial and antiviral properties.

scholarly journals Influence of Different Pretreatments on the Antibacterial Properties of Chitosan Functionalized Viscose Fabric: TEMPO Oxidation and Coating with TEMPO Oxidized Cellulose Nanofibrils

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3144 ◽  
Author(s):  
Matea Korica ◽  
Zdenka Peršin ◽  
Snežana Trifunović ◽  
Katarina Mihajlovski ◽  
Tanja Nikolić ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Antibacterial Activity ◽  
Cellulose Nanofibrils ◽  
Antibacterial Properties ◽  
Value Added ◽  
Oxidized Cellulose ◽  
Tempo Oxidation ◽  
Medical Textiles ◽  
Washing Durability ◽  
Aldehyde Groups

The main objective of this study was to obtain chitosan functionalized viscose fabric with improved antibacterial properties and washing durability. In this regard carboxyl and aldehyde groups, as binding points for irreversible chitosan attachment into/onto viscose fabric, were introduced by two different pretreatments: 2,2,6,6-tetramethylpiperidine-1-oxy radical (TEMPO) oxidation and coating with TEMPO oxidized cellulose nanofibrils (TOCN). The Fourier transform infrared spectroscopy, elemental analysis, zeta potential measurements, scanning electron microscopy, breaking strength and antibacterial testing were used to evaluate the influence of these pretreatments on chitosan binding, but also on chemical, electrokinetic, morphological, mechanical and antibacterial properties of pretreated and chitosan functionalized viscose fabrics. Washing durability of chitosan functionalized viscose was monitored through changes in the chitosan content, electrokinetic and antibacterial properties after multiple washing. TOCN coating improves mechanical properties of fabric, while TEMPO oxidation deteriorates them. The results show that both pretreatments improve chitosan adsorption and thus antibacterial properties, which are highly durable to washing. After five washings, the chitosan functionalized pretreated viscose fabrics preserve their antibacterial activity against Staphylococcus aureus, while antibacterial activity against Escherichia coli was lost. TOCN coated and chitosan functionalized viscose fabric is a high value-added product with simultaneously improved antibacterial and mechanical properties, which may find application as medical textiles.

scholarly journals Effect of Silver Nanoparticles on Physicochemical and Antibacterial Properties of Calcium Silicate Cements

2016 ◽  
Vol 27 (5) ◽  
pp. 508-514 ◽  
Author(s):  
Fernando Vazquez-Garcia ◽  
◽  
Mário Tanomaru-Filho ◽  
Gisselle Moraima Chávez-Andrade ◽  
Roberta Bosso-Martelo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Silver Nanoparticles ◽  
Compressive Strength ◽  
Antibacterial Activity ◽  
Calcium Silicate ◽  
Setting Time ◽  
Antibacterial Properties ◽  
Mineral Trioxide Aggregate ◽  
Biological Properties ◽  
Calcium Silicate Cements

Abstract Mineral trioxide aggregate (MTA) and Portland cement (PC) are calcium silicate cements. They have similar physicochemical, mechanical and biological properties. The addition of zirconium oxide (ZrO2) to PC provides radiopacity. Silver nanoparticles (AgNPs) may improve some properties of cements. The aim of this study was to evaluate the effect of AgNPs on physicochemical/mechanical properties and antibacterial activity of white MTA (WMTA) and PC associated with ZrO2. The following materials were evaluated: WMTA; PC 70% + ZrO2 30%; WMTA+ AgNPs; and PC 70% + ZrO2 30% + AgNPs. The study evaluated radiopacity, setting time, pH, compressive strength and solubility. For radiopacity analysis, radiographs were made alongside an aluminum (Al) step wedge. To evaluate the antibacterial activity, direct contact test was performed on planktonic cells and Enterococcus faecalis biofilm induced on bovine root dentin for 14 days. The experimental periods were 5 and 15 h. Data were obtained as CFU mL-1. The obtained data were submitted to ANOVA and Tukey tests (p<0.05). The addition of AgNPs to WMTA increased the pH, lowered the solubility and the initial and final setting times. The addition of AgNPs to PC/ZrO2 maintained the pH, lowered the solubility, and increased the setting time and compressive strength. The radiopacity of all materials was higher than 4 mmAl. The addition of AgNPs promoted an increase in antibacterial activity for calcium silicate cements and favored the physicochemical and mechanical properties of the materials.

scholarly journals Studies of properties of polypropylene/halloysite composites

2011 ◽  
Vol 13 (3) ◽  
pp. 61-65 ◽  
Author(s):  
Agnieszka Szczygielska ◽  
Jacek Kijeński
Keyword(s):  
Mechanical Properties ◽  
Thermal Properties ◽  
Polymer Composites ◽  
Degree Of Crystallinity ◽  
Mechanical And Thermal Properties ◽  
Thermal And Mechanical Properties ◽  
Polypropylene Composites ◽  
Modification Method ◽  
The Degree Of Crystallinity

Studies of properties of polypropylene/halloysite compositesThe results of the studies on the synthesis, mechanical and thermal properties of polypropylene composites with various amount of halloysite filler are presented. Halloysite (HNT) belongs to the silica type characterized by a two-layer 1:1 structure. This work was aimed to develop a method for the modification of halloysite in its prime use as a filler for polypropylene by extrusion. The composites contain 1, 3, 5 and 7 wt.% of HNT. The degree of crystallinity of the composites decrease with increasing halloysite content. The results confirm the expectations that composites of interesting physicochemical, mechanical and thermal properties can be obtained. The mechanical properties studied show that the filler modification method used leads to the synthesis of polymer composites of improved thermal and mechanical properties.

Changes of color and antibacterial characteristics of knitted fabrics dyed with reactive dyes after treatment with a nanocomposition of silver and carboxymethyl starch

2021 ◽  
pp. 004051752110505
Author(s):  
Ainur Bektursunova ◽  
Nurzhan Botabayev ◽  
Gani Yerkebay ◽  
Donyor Nabiev
Keyword(s):  
Antibacterial Activity ◽  
Colorimetric Method ◽  
Antibacterial Properties ◽  
Color Difference ◽  
Ag Nps ◽  
Knitted Fabrics ◽  
Textile Materials ◽  
Carboxymethyl Starch ◽  
Color Changes ◽  
Silver Nps

Changes in the color characteristics of knitted fabrics after bactericidal finishes were studied by the colorimetric method. Antibacterial activity was tested with regard to gram-negative bacterium E. coli and gram-positive bacterium S. aureus. The strongest color changes due to the presence of Ag NPs were observed on samples dyed with lighter shades, where the color difference was mainly caused by the change in lightness and brightness. After treatment with silver NPs, the colors in samples dyed with Navy K-EN and Black NN are deepened, that is, the color intensity increases many times and the reflection coefficient decreases. Due to this effect, darker color tones can be achieved using less dye. The dyed knitted fabrics modified with Ag-carboxymethyl starch (AgCMS) NPs exhibited excellent antibacterial properties regardless of the dye color used. The dyeing did not affect the antibacterial activity of fabrics modified with AgCMS nanocomposites. The research on the resistance of the dyed knitted fabrics treated with nanocomposite AgCMS solution to washing showed the preservation of a sufficiently high antimicrobial activity, slightly decreasing only after the 10th wash in a washing solution. This is proved by exceptional resistance to washing of knitted fabrics modified with AgCMS. The results of the research allow one to solve the problem of expanding the range of antibacterial products and special clothes by treating textile materials with silver and carboxymethyl starch NPs.

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