The effects of ZnO nanoparticle reinforcement on thermostability, mechanical, and optical properties of the biodegradable PBAT film

Abstract Among various nanomaterials used for food packaging, zinc oxide (ZnO) nanoparticles are one of the best choices due to their high antimicrobial property. However, for biodegradable materials like poly(butylene adipate-co-terephthalate) (PBAT), biodegradability can be limited by the antibacterial function. Thus, in the present study, reinforced PBAT films with different weight percentages (1, 3, and 5 wt%) of ZnO nanoparticles were prepared by the casting process to investigate the effects of ZnO on the thermostability, mechanical, and antimicrobial properties of the PBAT film. The results showed that the small amount of ZnO (1 wt%) reduced the decomposition temperature of the PBAT film by nearly 50 °C, and the thermal stability was significantly decreased with the increasing ZnO content. Melt flow index comparison showed that the ZnO nanoparticles accelerated the room temperature degradation rate of PBAT films. In addition, due to the degradation effect of ZnO nanoparticles, the mechanical properties such as the total percentage of elongation (at break), the tensile strength, and yield strength decreased with the addition of ZnO nanoparticles. The antibacterial test showed that PBAT + 1 wt% ZnO films could achieve high antibacterial activity (R = 6.8) against Escherichia coli. This study is important for controlling the degradation period of biodegradable materials.

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Interference of Biodegradable Plastics in the Polypropylene Recycling Process

Materials ◽

10.3390/ma11101886 ◽

2018 ◽

Vol 11 (10) ◽

pp. 1886 ◽

Cited By ~ 14

Author(s):

María Samper ◽

David Bertomeu ◽

Marina Arrieta ◽

José Ferri ◽

Juan López-Martínez

Keyword(s):

Biodegradable Polymers ◽

Food Packaging ◽

Structural Changes ◽

Mechanical Performance ◽

Crop Protection ◽

Melt Flow Index ◽

Thermoplastic Starch ◽

Flow Index ◽

Moulding Process ◽

Injection Moulding Process

Recycling polymers is common due to the need to reduce the environmental impact of these materials. Polypropylene (PP) is one of the polymers called ‘commodities polymers’ and it is commonly used in a wide variety of short-term applications such as food packaging and agricultural products. That is why a large amount of PP residues that can be recycled are generated every year. However, the current increasing introduction of biodegradable polymers in the food packaging industry can negatively affect the properties of recycled PP if those kinds of plastics are disposed with traditional plastics. For this reason, the influence that generates small amounts of biodegradable polymers such as polylactic acid (PLA), polyhydroxybutyrate (PHB) and thermoplastic starch (TPS) in the recycled PP were analyzed in this work. Thus, recycled PP was blended with biodegradables polymers by melt extrusion followed by injection moulding process to simulate the industrial conditions. Then, the obtained materials were evaluated by studding the changes on the thermal and mechanical performance. The results revealed that the vicat softening temperature is negatively affected by the presence of biodegradable polymers in recycled PP. Meanwhile, the melt flow index was negatively affected for PLA and PHB added blends. The mechanical properties were affected when more than 5 wt.% of biodegradable polymers were present. Moreover, structural changes were detected when biodegradable polymers were added to the recycled PP by means of FTIR, because of the characteristic bands of the carbonyl group (between the band 1700–1800 cm−1) appeared due to the presence of PLA, PHB or TPS. Thus, low amounts (lower than 5 wt.%) of biodegradable polymers can be introduced in the recycled PP process without affecting the overall performance of the final material intended for several applications, such as food packaging, agricultural films for farming and crop protection.

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Thin Film Gas Sensors Based on Planetary Ball-Milled Zinc Oxide Nanoinks: Effect of Milling Parameters on Sensing Performance

Applied Sciences ◽

10.3390/app11209676 ◽

2021 ◽

Vol 11 (20) ◽

pp. 9676

Author(s):

Raju Sapkota ◽

Pengjun Duan ◽

Tanay Kumar ◽

Anusha Venkataraman ◽

Chris Papadopoulos

Keyword(s):

Thin Film ◽

Zinc Oxide ◽

Gas Sensors ◽

Zno Nanoparticles ◽

Food Packaging ◽

Room Temperature ◽

Industrial Applications ◽

Sensor Response ◽

Particle Sizes ◽

Zno Nanoparticle

Planetary ball-milled zinc oxide (ZnO) nanoparticle suspensions (nanoinks) were used to produce thin film chemiresistive gas sensors that operate at room temperature. By varying milling or grinding parameters (speed, time, and solvent) different thin film gas sensors with tunable particle sizes and porosity were fabricated and tested with dry air/oxygen against hydrogen, argon, and methane target species, in addition to relative humidity, under ambient light conditions. Grinding speeds of up to 1000 rpm produced particle sizes and RMS thin film roughness below 100 nm, as measured by atomic force and scanning electron microscopy. Raman spectroscopy, photoluminescence, and X-ray analysis confirmed the purity and structure of the resulting ZnO nanoparticles. Gas sensor response at room temperature was found to peak for nanoinks milled at 400 rpm and for 30 min in ethylene glycol and deionized water, which could be correlated to an increased film porosity and enhanced variation in electron concentration resulting from adsorption/desorption of oxygen ions on the surfaces of ZnO nanoparticles. Sensor response and dynamic behavior was found to improve as the temperature was increased, peaking between 100 and 150 °C. This work demonstrates the use of low-cost PBM nanoinks as the active materials for solution-processed thin film gas/humidity sensors for use in environmental, medical, food packaging, laboratory, and industrial applications.

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Determination of the Tensile Properties and Biodegradability of Cornstarch-Based Biopolymers Plasticized with Sorbitol and Glycerol

Polymers ◽

10.3390/polym13213709 ◽

2021 ◽

Vol 13 (21) ◽

pp. 3709

Author(s):

M. M. Harussani ◽

S. M. Sapuan ◽

A. H. M. Firdaus ◽

Yaser A. El-Badry ◽

Enas E. Hussein ◽

...

Keyword(s):

Thin Film ◽

Mechanical Properties ◽

Tensile Strength ◽

Young’S Modulus ◽

Food Packaging ◽

Young's Modulus ◽

Casting Process ◽

Biodegradable Materials ◽

And Performance

In this study, the effects of various quantities of sorbitol and glycerol plasticizers (0%, 30%, 45%, and 60%) on cornstarch-based film were examined to develop a novel polymer for usage with biodegradable materials. The film was prepared using the casting process. According to the test findings, the application of the plasticizer concentrations affected the thickness, moisture content, and water absorption of the film. When plasticizer concentrations were increased to 60%, the tensile stress and Young’s modulus of plasticized films dropped regardless of plasticizer type. However, the thin film with addition of 30% sorbitol plasticizer demonstrated a steady value of Young’s modulus (60.17 MPa) with an increase in tensile strength (13.61 MPa) of 46%, while the lowest combination of tensile strength and Young’s modulus is the film that was plasticized with 60% glycerol, with 2.33 MPa and 16.23 MPa, respectively. In summary, the properties and performance of cornstarch-based film were greatly influenced by plasticizer types and concentrations. The finest set of features in this research appeared in the film plasticized with 30% sorbitol, which achieved the best mechanical properties for food packaging applications.

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Role of Zno Nanoparticles in Enhancing the Antimicrobial Property of Nitrocellulose Lacquer Wood Finish

Current Materials Science ◽

10.2174/1874464812666190408143026 ◽

2019 ◽

Vol 12 (1) ◽

pp. 91-98

Author(s):

Shikhar Shukla ◽

Shailendra Kumar ◽

Ismita Nautiyal ◽

Kishan Kumar V.S

Keyword(s):

Antimicrobial Activity ◽

Zno Nanoparticles ◽

Antimicrobial Property ◽

Economic Loss ◽

Analysis Data ◽

Wood Products ◽

Mould Growth ◽

Neem Oil ◽

Nano Zno ◽

Aesthetic Appearance

Background: Mould growth on coated wood products during shipment is the foremost apprehension for most of the wood industries in India. Well finished wood products tend to get deposited by staining moulds superficially in high humidity conditions during shipment. Though wood disfiguring fungi (stain moulds) normally have no significant effect on the mechanical properties of timber, they only affect the aesthetic appearance of the material without destructing the wood cell wall. This causes a huge economic loss to the manufacturer due to disfigurement of the appearance of wood products. Methods: The aim of this work is to test and enhance antimicrobial property of Nitrocellulose lacquer wood finish to prevent mould deposition on coated wood products. The work was carried out to screen and evaluate the antimicrobial activity of commercial Nitrocellulose lacquer. Several patents regarding antimicrobial activity of nano metal oxides have been visited. In order to enhance the mould resistance of this coating, its combinations with neem oil and ZnO nanoparticles were prepared and tested against the growth of staining moulds: Aspergillus niger and Penicillium sp. on the wood substrate of Melia dubia. The study was carried out for 500 hours under favorable conditions (Temperature and Relative Humidity (RH)) for the mould growth. The growth was analysed on the basis of surface area affected by stain moulds on coated wood samples. Results: The growth analysis data inferred that the ZnO nanoparticles had significant effect against the growth of stain moulds. The presence of ZnO nanoparticles increased the mould growth resistance of Nitrocellulose lacquer coating to a great extent compared to the ability of neem oil for the same. This finding demonstrates the potential use of nano ZnO for increasing the effectiveness of NC lacquer against mould growth without hampering its other properties. Conclusion: 1 % nano ZnO concentration in Nitrocellulose lacquer wood coating increased its efficacy against staining mould growth by 95 %.

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Sputter-Deposited Ag Nanoparticles on Electrospun PCL Scaffolds: Morphology, Wettability and Antibacterial Activity

Coatings ◽

10.3390/coatings11030345 ◽

2021 ◽

Vol 11 (3) ◽

pp. 345

Author(s):

Daniele Valerini ◽

Loredana Tammaro ◽

Roberta Vitali ◽

Gloria Guillot ◽

Antonio Rinaldi

Keyword(s):

Ag Nanoparticles ◽

Food Packaging ◽

Antimicrobial Agents ◽

Antimicrobial Properties ◽

Deposition Process ◽

Polymer Fibers ◽

Antibacterial Action ◽

Porous Scaffolds ◽

Electrospinning Technique ◽

Sputtering Deposition

Porous scaffolds made of biocompatible and environmental-friendly polymer fibers with diameters in the nano/micro range can find applications in a wide variety of sectors, spanning from the biomedical field to textiles and so on. Their development has received a boost in the last decades thanks to advances in the production methods, such as the electrospinning technique. Conferring antimicrobial properties to these fibrous structures is a primary requirement for many of their applications, but the addition of antimicrobial agents by wet methods can present a series of drawbacks. In this work, strong antibacterial action is successfully provided to electrospun polycaprolactone (PCL) scaffolds by silver (Ag) addition through a simple and flexible way, namely the sputtering deposition of silver onto the PCL fibers. SEM-EDS analyses demonstrate that the polymer fibers get coated by Ag nanoparticles without undergoing any alteration of their morphological integrity upon the deposition process. The influence on wettability is evaluated with polar (water) and non-polar (diiodomethane) liquids, evidencing that this coating method allows preserving the hydrophobic character of the PCL polymer. Excellent antibacterial action (reduction > 99.995% in 4 h) is demonstrated against Escherichia coli. The easy fabrication of these PCL-Ag mats can be applicable to the production of biomedical devices, bioremediation and antifouling systems in filtration, personal protective equipment (PPE), food packaging materials, etc.

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Laboratory Study of the Ultraviolet Radiation Effect on an HDPE Geomembrane

Membranes ◽

10.3390/membranes11060390 ◽

2021 ◽

Vol 11 (6) ◽

pp. 390

Author(s):

Fernando Luiz Lavoie ◽

Marcelo Kobelnik ◽

Clever Aparecido Valentin ◽

Érica Fernanda da Silva Tirelli ◽

Maria de Lurdes Lopes ◽

...

Keyword(s):

Ultraviolet Radiation ◽

Morphological Changes ◽

Field Performance ◽

Melt Flow Index ◽

Flow Index ◽

Test Results ◽

Upward Trend ◽

Scanning Calorimetry ◽

Ultraviolet Exposure ◽

Brittle Behavior

High-density polyethylene (HDPE) geomembranes are polymeric geosynthetic materials usually applied as a liner in environmental facilities due to their good mechanical properties, good welding conditions, and excellent chemical resistance. A geomembrane’s field performance is affected by different conditions and exposures, including ultraviolet radiation, thermal and oxidative exposure, and chemical contact. This article presents an experimental study with a 1.0 mm-thick HDPE virgin geomembrane exposed by the Xenon arc weatherometer for 2160 h and the ultraviolet fluorescent weatherometer for 8760 h to understand the geomembrane’s behavior under ultraviolet exposure. The evaluation was performed using the melt flow index (MFI) test, oxidative-induction time (OIT) tests, tensile test, differential scanning calorimetry (DSC) analysis, and Fourier transform infrared spectroscopy (FTIR) analysis. The sample exposed in the Xenon arc equipment showed a tendency to increase the MFI values during the exposure time. This upward trend may indicate morphological changes in the polymer. The tensile behavior analysis showed a tendency of the sample to lose ductility, without showing brittle behavior. The samples’ OIT test results under both device exposures showed faster antioxidant depletion for the standard OIT test than the high-pressure OIT test. The DSC and FTIR analyses did not demonstrate the polymer’s changes.

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Enhancement of mechanical, thermal and water uptake performance of TPU/jute fiber green composites via chemical treatments on fiber surface

e-Polymers ◽

10.1515/epoly-2020-0015 ◽

2020 ◽

Vol 20 (1) ◽

pp. 133-143 ◽

Cited By ~ 6

Author(s):

Tuffaha Fathe Salem ◽

Seha Tirkes ◽

Alinda Oyku Akar ◽

Umit Tayfun

Keyword(s):

Water Absorption ◽

Water Uptake ◽

Mechanical Test ◽

Fiber Surface ◽

Melt Flow Index ◽

Jute Fiber ◽

Morphological Properties ◽

Flow Index ◽

Melt Flow ◽

Treatment Type

AbstractChopped jute fiber (JF) surfaces were modified using alkaline, silane and eco-grade epoxy resin. Surface characteristics of jute fibers were confirmed by FTIR and EDX analyses. JF filled polyurethane elastomer (TPU) composites were prepared via extrusion process. The effect of surface modifications of JF on mechanical, thermo-mechanical, melt-flow, water uptake and morphological properties of TPU-based eco-composites were investigated by tensile and hardness tests, dynamic mechanical analysis (DMA), melt flow index (MFI) test, water absorption measurements and scanning electron microscopy (SEM) techniques, respectively. Mechanical test results showed that silane and epoxy treated JF additions led to increase in tensile strength, modulus and hardness of TPU. Glass transition temperature (Tg) of TPU rose up to higher values after JF inclusions regardless of treatment type. Si-JF filled TPU exhibited the lowest water absorption among composites. Surface treated JFs displayed homogeneous dispersion into TPU and their surface were covered by TPU according to SEM micro-photographs.

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Polydopamine-Inspired Surface Modification of Polypropylene Hernia Mesh Devices via Cold Oxygen Plasma: Antibacterial and Drug Release Properties

Coatings ◽

10.3390/coatings9030164 ◽

2019 ◽

Vol 9 (3) ◽

pp. 164 ◽

Cited By ~ 3

Author(s):

Xiakeer Saitaer ◽

Noor Sanbhal ◽

Yansha Qiao ◽

Yan Li ◽

Jing Gao ◽

...

Keyword(s):

Drug Release ◽

Plasma Treatment ◽

Oxygen Plasma ◽

Antimicrobial Property ◽

Antimicrobial Properties ◽

Major Complication ◽

Inhibition Zone ◽

Repair Process ◽

Hernia Surgery ◽

Maximum Inhibition

Mesh infection is a major complication of hernia surgery after polypropylene (PP) mesh implantation. Modifying the PP mesh with antibacterial drugs is an effective way to reduce the chance of infection, but the hydrophobic characteristic of PP fibers has obstructed the drug adhesion. Therefore, to prepare antimicrobial PP mesh with a stable drug coating layer and to slow the drug release property during the hernia repair process has a great practical meaning. In this work, PP meshes were coated by bio-inspired polydopamine (PDA), which can load and release levofloxacin. PP meshes were activated with cold oxygen plasma and then plasma activated PP fibers were coated with PDA. The PDA coated meshes were further soaked in levofloxacin. The levofloxacin loaded PP meshes demonstrate excellent antimicrobial properties for 6 days and the drug release has lasted for at least 24 h. Moreover, a control PP mesh sample without plasma treatment was also prepared, after coating with PDA and loading levofloxacin. The antimicrobial property was sustained only for two days. The maximum inhibition zone of PDA coated meshes with and without plasma treatment was 12.5 and 9 mm, respectively. On all accounts, the modification strategy can facilely lead to long-term property of infection prevention.

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Green TPUs from Prepolymer Mixtures Designed by Controlling the Chemical Structure of Flexible Segments

International Journal of Molecular Sciences ◽

10.3390/ijms22147438 ◽

2021 ◽

Vol 22 (14) ◽

pp. 7438

Author(s):

Paulina Kasprzyk ◽

Ewa Głowińska ◽

Paulina Parcheta-Szwindowska ◽

Kamila Rohde ◽

Janusz Datta

Keyword(s):

Chemical Structure ◽

Melt Flow Index ◽

Molar Ratio ◽

Flow Index ◽

Step Method ◽

Elongation At Break ◽

Molecular Weights ◽

Trimethylene Glycol ◽

Hard Segments ◽

A Chain

This study concerns green thermoplastic polyurethanes (TPU) obtained by controlling the chemical structure of flexible segments. Two types of bio-based polyether polyols—poly(trimethylene glycol)s—with average molecular weights ca. 1000 and 2700 Da were used (PO3G1000 and PO3G2700, respectively). TPUs were prepared via a two-step method. Hard segments consisted of 4,4′-diphenylmethane diisocyanates and the bio-based 1,4-butanodiol (used as a chain extender and used to control the [NCO]/[OH] molar ratio). The impacts of the structure of flexible segments, the amount of each type of prepolymer, and the [NCO]/[OH] molar ratio on the chemical structure and selected properties of the TPUs were verified. By regulating the number of flexible segments of a given type, different selected properties of TPU materials were obtained. Thermal analysis confirmed the high thermal stability of the prepared materials and revealed that TPUs based on a higher amount of prepolymer synthesized from PO3G2700 have a tendency for cold crystallization. An increase in the amount of PO3G1000 at the flexible segments caused an increase in the tensile strength and decrease in the elongation at break. Melt flow index results demonstrated that the increase in the amount of prepolymer based on PO3G1000 resulted in TPUs favorable in terms of machining.

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Halloysite Nanotubes and Silane-Treated Alumina Trihydrate Hybrid Flame Retardant System for High-Performance Cable Insulation

Polymers ◽

10.3390/polym13132134 ◽

2021 ◽

Vol 13 (13) ◽

pp. 2134

Author(s):

Sandra Paszkiewicz ◽

Izabela Irska ◽

Iman Taraghi ◽

Elżbieta Piesowicz ◽

Jakub Sieminski ◽

...

Keyword(s):

Mechanical Properties ◽

Polymer Blend ◽

Hybrid System ◽

Reference Sample ◽

Melt Flow Index ◽

Halloysite Nanotubes ◽

Flow Index ◽

Scanning Calorimetry ◽

Limiting Oxygen Index ◽

Alumina Trihydrate

The effect of the presence of halloysite nanotubes (HNTs) and silane-treated alumina trihydrate (ATH-sil) nanofillers on the mechanical, thermal, and flame retardancy properties of ethylene-vinyl acetate (EVA) copolymer/low-density polyethylene (LDPE) blends was investigated. Different weight percentages of HNT and ATH-sil nanoparticles, as well as the hybrid system of those nanofillers, were melt mixed with the polymer blend (reference sample) using a twin-screw extruder. The morphology of the nanoparticles and polymer compositions was studied using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The mechanical properties, hardness, water absorption, and melt flow index (MFI) of the compositions were assessed. The tensile strength increases as a function of the amount of HNT nanofiller; however, the elongation at break decreases. In the case of the hybrid system of nanofillers, the compositions showed superior mechanical properties. The thermal properties of the reference sample and those of the corresponding sample with nanofiller blends were studied using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Two peaks were observed in the melting and crystallization temperatures. This shows that the EVA/LDPE is an immiscible polymer blend. The thermal stability of the blends was improved by the presence of HNTs and ATH-sil nanoparticles. Thermal degradation temperatures were shifted to higher values by the presence of hybrid nanofillers. Finally, the flammability of the compositions was assessed. Flammability as reflected by the limiting oxygen index (OI) was increased by the presence of HNT and ATH-sil nanofiller and a hybrid system of the nanoparticles.

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