MyMedR

Displaying publications 1 - 20 of 300 in total

Abstract:

Sort:

Fulltext Synthesis of a new biocomposite for fertiliser coating: assessment of biodegradability and thermal stability

Ketabchi MR, Masoudi Soltani S, Chan A

Environ Sci Pollut Res Int, 2023 Sep;30(41):93722-93730.
PMID: 37515618 DOI: 10.1007/s11356-023-28892-0

The bio- and thermal degradation as well as the water absorption properties of a novel biocomposite comprising cellulose nanoparticles, natural rubber and polylactic acid have been investigated. The biodegradation process was studied through an assembled condition based on the soil collected from the central Malaysian palm oil forests located in the University of Nottingham Malaysia. The effects of the presence of the cellulose nanoparticles and natural rubber on the biodegradation of polylactic acid were investigated. The biodegradation process was studied via thermal gravimetric analysis and scanning electron microscopy. It was understood that the reinforcement of polylactic acid with cellulose nanoparticles and natural rubber increases the thermal stability by ~ 20 °C. Limited amorphous regions on the surface of the cellulose nanoparticles accelerated the biodegradation and water absorption processes. Based on the obtained results, it is predicted that complete biodegradation of the synthesised biocomposites can take place in 3062 h, highlighting promising agricultural applications for this biocomposite.

Matched MeSH terms: Tensile Strength
A novel approach to evaluate the mechanical responses of elastin-like bioresorbable poly(glycolide-co-caprolactone) (PGCL) suture

Low YJ, Kittur MI, Andriyana A, Ang BC, Zainal Abidin NI

J Mech Behav Biomed Mater, 2023 Apr;140:105723.
PMID: 36821908 DOI: 10.1016/j.jmbbm.2023.105723

Poly(glycolide-co-caprolactone) (PGCL) has become a novice to the bioresorbable suture owing to the synergistic properties taken from the homo-polyglycolide (PGA) and polycaprolactone (PCL) such as excellent bioresorption and flexibility. In addition to under conventional monotonic loading, the understanding of mechanical responses of PGCL copolymers under complex loading conditions such as cyclic and stress relaxation is crucial for its application as a surgical suture. Consequently, the present work focuses on evaluating the mechanical responses of PGCL sutures under monotonic, cyclic, and stress relaxation loading conditions. Under monotonic loading, the stress-strain behavior of the PGCL suture was found to be non-linear with noticeable strain-rate dependence. Under cyclic loading, inelastic responses including stress-softening, hysteresis and permanent set were observed. During cyclic loading, both stress-softening and hysteresis were found to increase with the maximum strain. In multi-step stress relaxation, the PGCL sutures were observed to exhibit a strong viscoelastic response. In an attempt to describe the relationship between the stress-relaxation and strain-induced crystallization (SIC) occurring during the loading and relaxation processes, a schematic illustration of the conformational change of polymer chains in PGCL sutures was proposed in this work. Results showed that SIC was dependent on the strain level as well as the loading and relaxation durations. The inelastic phenomena observed in PGCL sutures can be thus correlated to the combined effect of stress relaxation and SIC.

Matched MeSH terms: Tensile Strength
Development of a bioactive dentin adhesive resin modified with magnesium-doped synthetic hydroxyapatite crystals

Daood U, Fawzy A

J Mech Behav Biomed Mater, 2023 Apr;140:105737.
PMID: 36827934 DOI: 10.1016/j.jmbbm.2023.105737

The aim is to evaluate the development of an experimental multi-mode/Universal resin-based dentin adhesive modified with synthetic Mg2+ doped hydroxyapatite crystals (HAp) having self-remineralization and antibiofilm properties. HAp doped with Mg2+ was prepared by the precipitation method. Experimental adhesives were subjected to degree of conversion and X-ray diffraction test for size and crystal structure. Bond strength was tested, and electron microscopy (SEM/TEM) imaging of resin-dentin interface was done along with nanoleakage, nanoindentation, confocal and Raman analyses. S. mutans was analysed using CLSM images against modified adhesive specimens. Nucleating abilities within the resin-dentin specimens are determined by measuring Ca2+. Alkaline phosphatase, Runx2, and Ocn transcripts are amplified using quantitative polymerase chain reaction (q-PCR). A calcium assay is performed to quantify level of mineralisation. When compared to control adhesives, the 0.5% Hap/Mg2+ containing experimental dentin adhesive demonstrated improved interaction with dentin. The preservation of uniform intact hybrid layer with the absence of nanoleakage indicated dentin bond integrity with 0.5% HAP/Mg2+ modified adhesive. Self-remineralization and antibiofilm potentials are supported.

Matched MeSH terms: Tensile Strength
The Effect of Topical Agents on the Tensile Strength of Absorbable and Non-absorbable Suture Materials-An in Vitro Study

Alnaqi A, Burhamah W, Al-Sultan AT, Taqi E

World J Surg, 2023 Feb;47(2):448-454.
PMID: 36316513 DOI: 10.1007/s00268-022-06788-3

INTRODUCTION: Topical agents are sometimes applied to surgical wounds after closure; these may include antiseptics or antibiotics. Minimal research has been undertaken to investigate the effect of topical regimens on the tensile strength of suture materials.
AIM: To investigate the effect of four commonly used wound care regimens on the tensile strength of suture materials.
METHODS: The failure load of 9 different suture materials was tested using the Instron Electroplus E3000 tensile testing machine (Instron Corporation, Norwood, Massachusetts). Tensile strength was represented as the failure load, measured in Newtons (N), and defined as the maximal load that could be applied across the suture prior to failure. Each suture was tested dry and after immersion in one of 4 products for 7 days and tested on day 7. The immersion agents tested were: sodium chloride 0.9%, MicroSafe® (Sonoma Pharmaceuticals, Petaluma, CA), Aqueous Povidone-iodine 10% solution (Betadine-Mundipharma), and Fucidin ointment.
RESULTS: Sodium chloride 0.9%, MicroSafe®, Aqueous Povidone-iodine 10%, and Fucidin seem to increase the failure load of most absorbable and non-absorbable sutures. However, the failure load of Polyglactin 910 suture (Surgilactin, coated, violet-Ethicon) is reduced by long-term exposure to either sodium chloride 0.9% or MicroSafe®, while the failure load of the Polydioxanone suture (PDS Plus-Ethicon) is reduced by long-term exposure to MicroSafe® only.
CONCLUSION: In our experiment, the commonly used wound care products have been shown to alter the tensile strength of suture materials. Further human studies are required to ascertain the clinical validity and applicability of our findings.

Matched MeSH terms: Tensile Strength
Preparation and characterization of bioplastics from silylated cassava starch and epoxidized soybean oils

Yang J, Xu S, Wang W, Ran X, Ching YC, Sui X, et al.

Carbohydr Polym, 2023 Jan 15;300:120253.
PMID: 36372510 DOI: 10.1016/j.carbpol.2022.120253

In this work, a systematic coupling study of silane coupling agent between starch and epoxidized soybean oils (ESO) was carried out. Starch was modified by 3-aminopropyl trimethoxy silane (APMS) with various contents of NaOH. The APMS-modified starch was incorporated with ESO to synthesize the bioplastics by solution casting. As demonstrated by the FTIR spectra, the hydrogen bond interactions among starch molecules were inhibited by the modification. This outcome provided higher interaction and compatibility of starch with ESO, as confirmed by FESEM. TGA showed that the thermal stability of starch decreased considerably after the silylation. In contrast, the produced bioplastics with silylated starch exhibited higher thermal stability than the control sample. Regarding the bioplastics, an obvious increase of tensile strength from 5.78 MPa to 9.29 MPa was obtained. This work suggested a simple and effective modification technique by APMS to improve compatibility of starch/ESO-based bioplastics with superior mechanical and thermal properties.

Matched MeSH terms: Tensile Strength
Effect of hybridization composition and glycerin content on novel corn starch/nata de coco plastic film: Thermal, mechanical, and degradation study

Mustapha SNH, Wan JS

Food Chem, 2022 Mar 30;373(Pt B):131440.
PMID: 34731804 DOI: 10.1016/j.foodchem.2021.131440

The objective of this work was to develop a plastic film from food sources with excellent thermal, mechanical, and degradability performance. Corn starch (CS)/nata de coco (NDC) were hybridized with addition of glycerin as plasticizer at different weight ratio and weight percent, respectively. Sample analysis found that the hybridization of CS with NDC improved the film forming properties, mechanical and thermal, degradation properties, as well as hydrophobicity and solubility of the film up to 0.5:0.5 wt hybrid ratio. The properties of the films were highly affected by the homogeneity of the sample during hybridization, with high NDC amount (0.3:0.7 wt CS:NDC) showing poor hydrophobicity, and mechanical and thermal properties. The glycerin content, however, did not significantly affect the hydrophobicity, water solubility, and degradability properties of CS/NDC film. Hybridization of 0.5:0.5 wt CS/NDC with 2 phr glycerin provided the optimum Young's modulus (15.67 MPa) and tensile strength (1.67 MPa) properties.

Matched MeSH terms: Tensile Strength
Biomechanical comparison of new Achilles tendon rupture repair technique the "Giftbox" versus the Krackow technique in New Zealand white rabbits: An experimental animal study

Hashim MH, Teo SH, Al-Fayyadh MZM, Mappiare S, Ng WM, Ali MRM

Injury, 2022 Feb;53(2):393-398.
PMID: 34740441 DOI: 10.1016/j.injury.2021.10.016

INTRODUCTION: To compare the strength between the Achilles tendons repaired with the "Giftbox" and the Krackow techniques in New Zealand white rabbits post six weeks of tendon healing.
MATERIALS AND METHODS: Eight rabbits were randomized into Giftbox and Krackow groups. Tenotomy was performed on the Achilles tendon of one side of the lower limb and repaired with the respective techniques. The contralateral limb served as control. Subjects were euthanized six weeks post-operative, and both repaired and control Achilles tendons were harvested for biomechanical tensile test.
RESULTS: The means of maximum load to rupture and tenacity in the Giftbox group (156.89 ± 38.49 N and 159.98 ± 39.25 gf/tex) were significantly different than Krackow's (103.55 ± 27.48 N and 104.91 ± 26.96 gf/tex, both p = 0.043).
CONCLUSION: The tendons repaired with Giftbox technique were biomechanically stronger than those repaired with Krackow technique after six weeks of tendon healing.

Matched MeSH terms: Tensile Strength
Thermoplastic starch/beeswax blend: Characterization on thermal mechanical and moisture absorption properties

Diyana ZN, Jumaidin R, Selamat MZ, Suan MSM

Int J Biol Macromol, 2021 Nov 01;190:224-232.
PMID: 34481857 DOI: 10.1016/j.ijbiomac.2021.08.201

Cassava starch has acquired many attentions owing to its ability to be developed as thermoplastic cassava starch (TPCS) where it can be obtained in low cost, making it to be one of alternatives to substitute petroleum-based plastic. An attempt was made to investigate the thermal, mechanical and moisture absorption properties of thermoplastic cassava starch blending with beeswax (TPCS-BW) fabricated using hot moulding compression method in the range of beeswax loading from 0, 2.5, 5 to 10 wt%. Addition of beeswax has significantly reduced tensile strength, elongation and flexural strength while improving tensile modulus and flexural modulus until 5 wt% beeswax. Incorporation of 10 wt% beeswax has successfully produced the lowest value of moisture absorption and water solubility among the bio-composite which might be attributed to the beeswax's hydrophobic properties in improving water barrier of the TPCS-BW bio-composite. Furthermore, the addition of beeswax resulted in the appearance of irregular and rough fractured surface. Meanwhile, fourier transform infrared (FT-IR) spectroscopy presented that incorporation of beeswax in the mixture has considerably improve hydrogen bonding of blends indicating good interaction between starch and beeswax. Hence, beeswax with an appropriate loading value able to improve the functional properties of TPCS-BW bio-composite.

Matched MeSH terms: Tensile Strength
Effect of plasticizers on physical, thermal, and tensile properties of thermoplastic films based on Dioscorea hispida starch

Hazrati KZ, Sapuan SM, Zuhri MYM, Jumaidin R

Int J Biol Macromol, 2021 Aug 31;185:219-228.
PMID: 34153358 DOI: 10.1016/j.ijbiomac.2021.06.099

This study examines the effects of varying the concentrations of sorbitol (S) and glycerol (G) on the physical, morphological, thermal, and mechanical properties of Dioscorea hispida, starch-based films. In this context, the films of Dioscorea hispida starch were developed using solution casting technique with glycerol (G), sorbitol (S), and a mixture of sorbitol-glycerol (SG) as plasticizers at the ratios of 0, 30, 45, and 60 wt%. The films' moisture contents were increased when increasing the plasticizer contents. The tensile strengths were decreased, but elongations at break were increased; 7.38%-11.54% for G-plasticized films, 10.17%-15.76% for S-plasticized films, and 14.41%- 16.10% for SG-plasticized films with increasing plasticizer concentrations of the film samples. Varying plasticizer concentrations exhibited a minor effect on the S-plasticized film's thermal properties. Significant decrement in the glass transition temperatures of Dioscorea hispida starch films was observed when the plasticizer contents were raised from 30% to 60%. Significantly, the present work has shown that plasticized Dioscorea hispida starch can be considered a promising biopolymer for the applications of biodegradable films.

Matched MeSH terms: Tensile Strength
Fulltext Propionic Anhydride Modification of Cellulosic Kenaf Fibre Enhancement with Bionanocarbon in Nanobiocomposites

Rizal S, Mistar EM, Oyekanmi AA, H P S AK, Alfatah T, Olaiya NG, et al.

Molecules, 2021 Jul 13;26(14).
PMID: 34299524 DOI: 10.3390/molecules26144248

The use of chemical modification of cellulosic fibre is applied in order to increase the hydrophobicity, hence improving the compatibility between the fibre and matrix bonding. In this study, the effect of propionic anhydride modification of kenaf fibre was investigated to determine the role of bionanocarbon from oil palm shell agricultural wastes in the improvement of the functional properties of bionanocomposites. The vinyl esters reinforced with unmodified and propionic anhydride modified kenaf fibres bio nanocomposites were prepared using 0, 1, 3, 5 wt% of bio-nanocarbon. Characterisation of the fabricated bionanocomposite was carried out using FESEM, TEM, FT-IR and TGA to investigate the morphological analysis, surface properties, functional and thermal analyses, respectively. Mechanical performance of bionanocomposites was evaluated according to standard methods. The chemical modification of cellulosic fibre with the incorporation of bionanocarbon in the matrix exhibited high enhancement of the tensile, flexural, and impact strengths, for approximately 63.91%, 49.61% and 54.82%, respectively. The morphological, structural and functional analyses revealed that better compatibility of the modified fibre-matrix interaction was achieved at 3% bionanocarbon loading, which indicated improved properties of the bionanocomposite. The nanocomposites exhibited high degradation temperature which signified good thermal stability properties. The improved properties of the bionanocomposite were attributed to the effect of the surface modification and bionanocarbon enhancement of the fibre-matrix networks.

Matched MeSH terms: Tensile Strength
Optimization of soy protein isolate, microbial transglutaminase and glucono-δ-lactone in gluten-free rice noodles

Ojukwu M, Ofoedu C, Seow EK, Easa AM

J Sci Food Agric, 2021 Jul;101(9):3732-3741.
PMID: 33301191 DOI: 10.1002/jsfa.11004

BACKGROUND: Rice flour does not contain gluten and lacks cohesion and extensibility, which is responsible for the poor texture of rice noodles. Different technologies have been used to mitigate this challenge, including hydrothermal treatments of rice flour, direct addition of protein in noodles, use of additives such as hydrocolloids and alginates, and microbial transglutaminase (MTG). Recently, the inclusion of soy protein isolate (SPI), MTG, and glucono-δ-lactone (GDL) in the rice noodles system yielded rice noodles with improved texture and more compact microstructure, hence the need to optimize the addition of SPI, MTG, and GDL to make quality rice noodles.
RESULTS: Numerical optimization showed that rice noodles prepared with SPI, 68.32 (g kg-1 of rice flour), MTG, 5.06 (g kg-1 of rice flour) and GDL, 5.0 (g kg-1 of rice flour) gave the best response variables; hardness (53.19 N), springiness (0.76), chewiness (20.28 J), tensile strength (60.35 kPa), and cooking time (5.15 min). The pH, sensory, and microstructure results showed that the optimized rice noodles had a more compact microstructure with fewer hollows, optimum pH for MTG action, and overall sensory panelists also showed the highest preference for the optimized formulation, compared to other samples selected from the numerical optimization and desirability tests.
CONCLUSION: Optimization of the levels of SPI, MTG, and GDL yielded quality noodles with improved textural, mechanical, sensory, and microstructural properties. This was partly due to the favourable pH value of the optimized noodles that provided the most suitable conditions for MTG crosslinking and balanced electrostatic interaction of proteins. © 2020 Society of Chemical Industry.

Matched MeSH terms: Tensile Strength
Fulltext Functional Properties of Antimicrobial Neem Leaves Extract Based Macroalgae Biofilms for Potential Use as Active Dry Packaging Applications

Oyekanmi AA, Kumar USU, H P S AK, Olaiya NG, Amirul AA, Rahman AA, et al.

Polymers (Basel), 2021 May 20;13(10).
PMID: 34065404 DOI: 10.3390/polym13101664

Antimicrobial irradiated seaweed-neem biocomposite films were synthesized in this study. The storage functional properties of the films were investigated. Characterization of the prepared films was conducted using SEM, FT-IR, contact angle, and antimicrobial test. The macroscopic and microscopic including the analysis of the functional group and the gas chromatography-mass spectrometry test revealed the main active constituents present in the neem extract, which was used an essential component of the fabricated films. Neem leaves' extracts with 5% w/w concentration were incorporated into the matrix of seaweed biopolymer and the seaweed-neem bio-composite film were irradiated with different dosages of gamma radiation (0.5, 1, 1.5, and 2 kGy). The tensile, thermal, and the antimicrobial properties of the films were studied. The results revealed that the irradiated films exhibited improved functional properties compared to the control film at 1.5 kGy radiation dosage. The tensile strength, tensile modulus, and toughness exhibited by the films increased, while the elongation of the irradiated bio-composite film decreased compared to the control film. The morphology of the irradiated films demonstrated a smoother surface compared to the control and provided surface intermolecular interaction of the neem-seaweed matrix. The film indicated an optimum storage stability under ambient conditions and demonstrated no significant changes in the visual appearance. However, an increase in the moisture content was exhibited by the film, and the hydrophobic properties was retained until nine months of the storage period. The study of the films antimicrobial activities against Staphylococcus aureus (SA), and Bacillus subtilis (BS) indicated improved resistance to bacterial activities after the incorporation of neem leaves extract and gamma irradiation. The fabricated irradiated seaweed-neem bio-composite film could be used as an excellent sustainable packaging material due to its effective storage stability.

Matched MeSH terms: Tensile Strength
Fulltext Kenaf Fiber/Pet Yarn Reinforced Epoxy Hybrid Polymer Composites: Morphological, Tensile, and Flammability Properties

Suriani MJ, Zainudin HA, Ilyas RA, Petrů M, Sapuan SM, Ruzaidi CM, et al.

Polymers (Basel), 2021 May 10;13(9).
PMID: 34068794 DOI: 10.3390/polym13091532

The application of natural fibers is rapidly growing in many sectors, such as construction, automobile, and furniture. Kenaf fiber (KF) is a natural fiber that is in demand owing to its eco-friendly and renewable nature. Nowadays, there are various new applications for kenaf, such as in absorbents and building materials. It also has commercial applications, such as in the automotive industry. Magnesium hydroxide (Mg(OH)2) is used as a fire retardant as it is low in cost and has good flame retardancy, while polyester yarn (PET) has high tensile strength. The aim of this study was to determine the horizontal burning rate, tensile strength, and surface morphology of kenaf fiber/PET yarn reinforced epoxy fire retardant composites. The composites were prepared by hybridized epoxy and Mg(OH)2 PET with different amounts of KF content (0%, 20%, 35%, and 50%) using the cold press method. The specimen with 35% KF (epoxy/PET/KF-35) displayed better flammability properties and had the lowest average burning rate of 14.55 mm/min, while epoxy/PET/KF-50 with 50% KF had the highest tensile strength of all the samples. This was due to fewer defects being detected on the surface morphology of epoxy/PET/KF-35 compared to the other samples, which influenced the mechanical properties of the composites.

Matched MeSH terms: Tensile Strength
Fulltext An Exploratory Study on Resistance Spot Welding of Titanium Alloy Ti-6Al-4V

Fatmahardi I, Mustapha M, Ahmad A, Derman MN, Lenggo Ginta T, Taufiqurrahman I

Materials (Basel), 2021 Apr 30;14(9).
PMID: 33946335 DOI: 10.3390/ma14092336

Resistance spot welding (RSW) is one of the most effective welding methods for titanium alloys, in particular Ti-6Al-4V. Ti-6Al-4V is one of the most used materials with its good ductility, high strength, weldability, corrosion resistance, and heat resistance. RSW and Ti-6Al-4V materials are often widely used in industrial manufacturing, particularly in automotive and aerospace industries. To understand the phenomenon of resistance spot weld quality, the physical and mechanical properties of Ti-6Al-4V spot weld are essential to be analyzed. In this study, an experiment was conducted using the Taguchi L9 method to find out the optimum level of the weld joint strength. The given optimum level sample was analyzed to study the most significant affecting RSW parameter, the failure mode, the weld nugget microstructure, and hardness values. The high heat input significantly affect the weld nugget temperature to reach and beyond the β-transus temperature. It led to an increase in the weld nugget diameter and the indentation depth. The expulsion appeared in the high heat input and decreased the weld nugget strength. It was caused by the molten material ejection in the fusion zone. The combination of high heat input and rapid air cooling at room temperature generated a martensite microstructure in the fusion zone. It increased the hardness, strength, and brittleness but decreased the ductility.

Matched MeSH terms: Tensile Strength
Fulltext Effect of Cellulose Nanofibrils on the Properties of Jatropha Oil-Based Waterborne Polyurethane Nanocomposite Film

Amri MR, Guan CT, Osman Al-Edrus SS, Md Yasin F, Mohamad SF

Polymers (Basel), 2021 Apr 30;13(9).
PMID: 33946517 DOI: 10.3390/polym13091460

The objective of this work was to study the influence of cellulose nanofibrils (CNF) on the physical, mechanical, and thermal properties of Jatropha oil-based waterborne polyurethane (WBPU) nanocomposite films. The polyol to produce polyurethane was synthesized from crude Jatropha oil through epoxidation and ring-opening method. The chain extender, 1,6-hexanediol, was used to improve film elasticity by 0.1, 0.25, and 0.5 wt.% of CNF loading was incorporated to enhance film performance. Mechanical performance was studied using a universal test machine as specified in ASTM D638-03 Type V and was achieved by 0.18 MPa at 0.5 wt.% of CNF. Thermal gravimetric analysis (TGA) was performed to measure the temperature of degradation and the chemical crosslinking and film morphology were studied using Fourier-transform infrared spectroscopy (FTIR) and field emission scanning electron microscopy (FESEM). The results showed that when the CNF was incorporated, it was found to enhance the nanocomposite film, in particular its mechanical and thermal properties supported by morphology. Nanocomposite film with 0.5 wt.% of CNF showed the highest improvement in terms of tensile strength, Young's modulus, and thermal degradation. Although the contact angle decreases as the CNF content increases, the effect on the water absorption of the film was found to be relatively small (<3.5%). The difference between the neat WPBU and the highest CNF loading film was not more than 1%, even after 5 days of being immersed in water.

Matched MeSH terms: Tensile Strength
Fulltext Improved Hydrophobicity of Macroalgae Biopolymer Film Incorporated with Kenaf Derived CNF Using Silane Coupling Agent

Oyekanmi AA, Saharudin NI, Hazwan CM, H P S AK, Olaiya NG, Abdullah CK, et al.

Molecules, 2021 Apr 13;26(8).
PMID: 33924692 DOI: 10.3390/molecules26082254

Hydrophilic behaviour of carrageenan macroalgae biopolymer, due to hydroxyl groups, has limited its applications, especially for packaging. In this study, macroalgae were reinforced with cellulose nanofibrils (CNFs) isolated from kenaf bast fibres. The macroalgae CNF film was after that treated with silane for hydrophobicity enhancement. The wettability and functional properties of unmodified macroalgae CNF films were compared with silane-modified macroalgae CNF films. Characterisation of the unmodified and modified biopolymers films was investigated. The atomic force microscope (AFM), SEM morphology, tensile properties, water contact angle, and thermal behaviour of the biofilms showed that the incorporation of Kenaf bast CNF remarkably increased the strength, moisture resistance, and thermal stability of the macroalgae biopolymer films. Moreover, the films' modification using a silane coupling agent further enhanced the strength and thermal stability of the films apart from improved water-resistance of the biopolymer films compared to unmodified films. The morphology and AFM showed good interfacial interaction of the components of the biopolymer films. The modified biopolymer films exhibited significantly improved hydrophobic properties compared to the unmodified films due to the enhanced dispersion resulting from the silane treatment. The improved biopolymer films can potentially be utilised as packaging materials.

Matched MeSH terms: Tensile Strength
Thermo-mechanical properties and sustainability analysis of newly developed eco-friendly structural foamed concrete by reusing palm oil fuel ash and eggshell powder as supplementary cementitious materials

Jhatial AA, Goh WI, Mastoi AK, Rahman AF, Kamaruddin S

Environ Sci Pollut Res Int, 2021 Mar 20.
PMID: 33745050 DOI: 10.1007/s11356-021-13435-2

The production of cement contributes to 10% of global carbon dioxide (CO2) pollution and 74 to 81% towards the total CO2 pollution by concrete. In addition to that, its low strength-to-weight ratio, high density and thermal conductivity are among the few limitations of heavy weight concrete. Therefore, this study was carried out to provide a solution to these limitations by developing innovative eco-friendly lightweight foamed concrete (LFC) of 1800 kg/m3 density incorporating 20-25% palm oil fuel ash (POFA) and 5-15% eggshell powder (ESP) by weight of total binder as supplementary cementitious material (SCM). The influence of combined utilization of POFA and ESP on the fresh state properties of eco-friendly LFC was determined using the J-ring test. To determine the mechanical properties, a total of 48 cubes and 24 cylinders were prepared for compressive strength, splitting tensile strength and modulus of elasticity each. A total of 24 panels were prepared to determine the thermal properties in terms of surface temperature and thermal conductivity. Furthermore, to assess the environmental impact and eco-friendliness of the developed LFC, the embodied carbon and eco-strength efficiency was calculated. It was determined that the utilization of POFA and ESP reduced the workability slightly but enhanced the mechanical properties of LFC (17.05 to 22.60 MPa compressive strength and 1.43 to 2.61 MPa tensile strength), thus satisfies the ACI213R requirements for structural lightweight concrete and that it can be used for structural applications. Additionally, the thermal conductivity reduced ranging from 0.55 to 0.63 W/mK compared to 0.82 W/mK achieved by control sample. Furthermore, the developed LFC showed a 16.96 to 33.55% reduction in embodied carbon and exhibited higher eco-strength efficiency between 47.82 and 76.97%. Overall, the combined utilization of POFA and ESP as SCMs not only enhanced the thermo-mechanical performance, makes the sustainable LFC as structural lightweight concrete, but also has reduced the environmental impacts caused by the disposal of POFA and ESP in landfills as well as reducing the total CO2 emissions during the production of eco-friendly LFC.

Matched MeSH terms: Tensile Strength
Fulltext On the Use of OPEFB-Derived Microcrystalline Cellulose and Nano-Bentonite for Development of Thermoplastic Starch Hybrid Bio-Composites with Improved Performance

Lai DS, Osman AF, Adnan SA, Ibrahim I, Alrashdi AA, Ahmad Salimi MN, et al.

Polymers (Basel), 2021 Mar 15;13(6).
PMID: 33803984 DOI: 10.3390/polym13060897

Thermoplastic starch (TPS) hybrid bio-composite films containing microcrystalline cellulose (C) and nano-bentonite (B) as hybrid fillers were studied to replace the conventional non-degradable plastic in packaging applications. Raw oil palm empty fruit bunch (OPEFB) was subjected to chemical treatment and acid hydrolysis to obtain C filler. B filler was ultra-sonicated for better dispersion in the TPS films to improve the filler-matrix interactions. The morphology and structure of fillers were characterized by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). TPS hybrid bio-composite films were produced by the casting method with different ratios of B and C fillers. The best ratio of B/C was determined through the data of the tensile test. FTIR analysis proved the molecular interactions between the TPS and the hybrid fillers due to the presence of polar groups in their structure. XRD analysis confirmed the intercalation of the TPS chains between the B inter-platelets as a result of well-developed interactions between the TPS and hybrid fillers. SEM images suggested that more plastic deformation occurred in the fractured surface of the TPS hybrid bio-composite film due to the higher degree of stretching after being subjected to tensile loading. Overall, the results indicate that incorporating the hybrid B/C fillers could tremendously improve the mechanical properties of the films. The best ratio of B/C in the TPS was found to be 4:1, in which the tensile strength (8.52MPa), Young's modulus (42.0 MPa), elongation at break (116.4%) and tensile toughness of the film were increased by 92%, 146%, 156% and 338%, respectively. The significantly improved strength, modulus, flexibility and toughness of the film indicate the benefits of using the hybrid fillers, since these features are useful for the development of sustainable flexible packaging film.

Matched MeSH terms: Tensile Strength
Fulltext Epidermal and fibroblast growth factors incorporated polyvinyl alcohol electrospun nanofibers as biological dressing scaffold

Asiri A, Saidin S, Sani MH, Al-Ashwal RH

Sci Rep, 2021 Mar 11;11(1):5634.
PMID: 33707606 DOI: 10.1038/s41598-021-85149-x

In this study, single, mix, multilayer Polyvinyl alcohol (PVA) electrospun nanofibers with epidermal growth factor (EGF) and fibroblast growth factor (FGF) were fabricated and characterized as a biological wound dressing scaffolds. The biological activities of the synthesized scaffolds have been verified by in vitro and in vivo studies. The chemical composition finding showed that the identified functional units within the produced nanofibers (O-H and N-H bonds) are attributed to both growth factors (GFs) in the PVA nanofiber membranes. Electrospun nanofibers' morphological features showed long protrusion and smooth morphology without beads and sprayed with an average range of 198-286 nm fiber diameter. The fiber diameters decrement and the improvement in wettability and surface roughness were recorded after GFs incorporated within the PVA Nanofibers, which indicated potential good adoption as biological dressing scaffolds due to the identified mechanical properties (Young's modulus) in between 18 and 20 MPa. The MTT assay indicated that the growth factor release from the PVA nanofibers has stimulated cell proliferation and promoted cell viability. In the cell attachment study, the GFs incorporated PVA nanofibers stimulated cell proliferation and adhered better than the PVA control sample and presented no cytotoxic effect. The in vivo studies showed that compared to the control and single PVA-GFs nanofiber, the mix and multilayer scaffolds gave a much more wound reduction at day 7 with better wound repair at day 14-21, which indicated to enhancing tissue regeneration, thus, could be a projected as a suitable burn wound dressing scaffold.

Matched MeSH terms: Tensile Strength
Preparation and characterization of curdlan/nanocellulose blended film and its application to chilled meat preservation

Qian Y, Bian L, Wang K, Chia WY, Khoo KS, Zhang C, et al.

Chemosphere, 2021 Mar;266:128948.
PMID: 33220979 DOI: 10.1016/j.chemosphere.2020.128948

In this study, to improve the mechanical and thermal properties of curdlan film, a curdlan/nanocellulose (NC) blended film was prepared and characterized for the first time. NC was successfully prepared from microcrystalline cellulose (MCC) with NaOH/urea treatment. The particle size of NC was observed to be 70-140 nm by cryo-electron microscope (cryo-EM). The blended film was prepared by adding the NC to curdlan solution. The tensile strength (TS) of the blended film reached the maximum value of 38.6 MPa, and the elongation at break (EB) was 40%. The DSC curve showed that the heat absorption peak of the film was 240 °C, indicating that the blended film has good temperature stability. Additionally, some other film properties were also improved, including gas barrier properties and transparency. Obvious morphological and molecular differences between the blended film and the pure curdlan film were discovered by SEM and FTIR analysis. Finally, the blended film was used for the preservation of chilled meat and extended the storage time of meat to 12 days. These results provided a theoretical basis for future application and development of biodegradable film.

Matched MeSH terms: Tensile Strength

Filters

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links