MyMedR

Displaying publications 61 - 80 of 301 in total

Abstract:

Sort:

The effect of spent coffee ground (SCG) loading, matrix ratio and biological treatment of SCG on poly(hydroxybutyrate) (PHB)/poly(lactic acid) (PLA) polymer blend

Boey JY, Kong U, Lee CK, Lim GK, Oo CW, Tan CK, et al.

Int J Biol Macromol, 2024 May;266(Pt 2):131079.
PMID: 38537860 DOI: 10.1016/j.ijbiomac.2024.131079

This study investigates the effects of SCG embedded into biodegradable polymer blends and aimed to formulate and characterise biomass-reinforced biocomposites using spent coffee ground (SCG) as reinforcement in PHB/PLA polymer blend. The effect of SCG filler loading and varying PHB/PLA ratios on the tensile properties and morphological characteristics of the biocomposites were examined. The results indicated that tensile properties reduction could be due to its incompatibility with the PHB/PLA matrixSCG aggregation at 40 wt% content resulted in higher void formation compared to lower content at 10 wt%. A PHB/PLA ratio of 50/50 with SCG loading 20 wt% was chosen for biocomposites with treated SCG. Biological treatment of SCG using Phanerochaete chrysosporium CK01 and Aspergillus niger DWA8 indicated P. chrysosporium CK01 necessitated a higher moisture content for optimum growth and enzyme production, whereas the optimal conditions for enzyme production (50-55 %, w/w) differed from those promoting A. niger DWA8 growth (40 %, w/w). SEM micrographs highlighted uniform distribution and effective wetting of treated SCG, resulting in improvements of tensile strength and modulus of biocomposites, respectively. The study demonstrated the effectiveness of sustainable fungal treatment in enhancing the interfacial adhesion between treated SCG and the PHB/PLA matrix.

Matched MeSH terms: Tensile Strength
Fulltext Feasibility of using latex examination gloves as dental dam: a tensile strength study

Budi Aslinie Md Sabri, Nur Hidayah Mohd Radzi, Fatimatuz Zahira Abdul Hadi, Ikmal HishamIsmai

Compendium of Oral Science, 2015;2(1):6-13.
MyJurnal

Objective: To evaluate feasibility of hand gloves as a rubber dam isolation alternative, in respect of physical properties. Materials and Methods: A randomized controlled trial study design was used. Three types of gloves were tested with two types of a rubber dam used as the control group. Cut-out pattern of dumb-bell shapes were made from 35 samples for each type of groups and tensile strength were tested using Universal Testing Machine and the Trapezium X software. All tests for physical requirements were performed in accord-ance with American Society for Testing and Materials D412, Standard Test Methods for Vulcanized Rubber and Thermoplastic Rubbers and Thermoplastic Elastomers-Tension. Findings were analyzed by analysis of vari-ance (ANOVA) and differences were compared using a Tukey-Kramer interval calculated at the 0.05 signifi-cance level. Results: Heavy gauge rubber dam has the highest Mean (calculated at the 0.05 significance level) except for maximum stress calculated at entire area. Medium-gauge rubber dam has significantly higher tensile strength (44.5075 N/mm2) when compared to heavy-gauge rubber dam (35.7787 N/mm2) although it was 0.09mm thinner. Discovery 2020 Powder Free Latex Examination Gloves with tensile strength value of 28.5922 N/mm2 (±3.27366) is more than the minimum requirement specified by American Federal Specification ZZ-R90B Rubber Dam (Dental, 1985) (4000 pounds per square inch or 27.6 N/mm2). For all variable tested, all groups are significantly different from each other. The mean square between the groups was quite large. Conclusion: This study shows that there are significant differences between the physical strength of latex gloves when com-pared to rubber dam. However, the comparison between thickness and tensile strength among various rubber dam, did not correspond proportionately. Only one type of rubber gloves met the minimum requirement but that is just one aspect. In view of these mixed results, more research is needed before we can conclude that it is feasable that we use hand gloves to replace rubber dam.

Matched MeSH terms: Tensile Strength
Recent Development in the Fabrication of Collagen Scaffolds for Tissue Engineering Applications: A Review

Busra MFM, Lokanathan Y

Curr Pharm Biotechnol, 2019;20(12):992-1003.
PMID: 31364511 DOI: 10.2174/1389201020666190731121016

Tissue engineering focuses on developing biological substitutes to restore, maintain or improve tissue functions. The three main components of its application are scaffold, cell and growthstimulating signals. Scaffolds composed of biomaterials mainly function as the structural support for ex vivo cells to attach and proliferate. They also provide physical, mechanical and biochemical cues for the differentiation of cells before transferring to the in vivo site. Collagen has been long used in various clinical applications, including drug delivery. The wide usage of collagen in the clinical field can be attributed to its abundance in nature, biocompatibility, low antigenicity and biodegradability. In addition, the high tensile strength and fibril-forming ability of collagen enable its fabrication into various forms, such as sheet/membrane, sponge, hydrogel, beads, nanofibre and nanoparticle, and as a coating material. The wide option of fabrication technology together with the excellent biological and physicochemical characteristics of collagen has stimulated the use of collagen scaffolds in various tissue engineering applications. This review describes the fabrication methods used to produce various forms of scaffolds used in tissue engineering applications.

Matched MeSH terms: Tensile Strength
Tensile properties of vulcanized field natural rubber latex by electron beam

Chai CK, Md. Soot Ahmad, Wan Manshol W. Zin

Sains Malaysiana, 2008;37.

Electron beam vulcanization of natural rubber latex has been developed as an alternative to the conventional sulphur vulcanization method. This study aimed at determining the effect of electron beam dose, beam current and centrifugation to the tensile properties of field natural rubber latex. Irradiation dose and beam current ranged from 50 to 300 kGy and 1 to 15 mA respectively. The determination of tensile properties were done on cast film prepared from irradiated field latex before and after centrifugation. It was found that tensile properties increased with radiation dose but decreased with beam current. Rubber films made from centrifuged irradiated field latex were softer and showed higher tensile strength.

Matched MeSH terms: Tensile Strength
Fulltext Enhanced mechanical and thermal properties of electrically conductive TPNR/GNP nanocomposites assisted with ultrasonication

Chen RS, Mohd Ruf MFH, Shahdan D, Ahmad S

PLoS One, 2019;14(9):e0222662.
PMID: 31545820 DOI: 10.1371/journal.pone.0222662

Thermoplastic natural rubber (TPNR) was compounded with graphene nanoplatelets (GNP) via ultrasonication and melt blending. The effects of ultrasonication period (1-4 hours) and GNP weight fraction (0.5, 1.0, 1.5 and 2.0 wt.%) on the mechanical, thermal and conductivity properties were investigated. Results showed that the 3 hours of ultrasonic treatment on LNR/GNP gave the greatest improvement in tensile strength of 25.8% (TPNR/GNP nanocomposites) as compared to those without ultrasonication. The TPNR nanocomposites containing 1.5 wt.% GNP exhibited the highest strength (16 MPa for tensile, 14 MPa for flexural and 11 kJm-2 for impact) and modulus (556 MPa and 869 MPa for tensile and flexural, respectively). The incorporation of GNP had enhanced the thermal stability. It can be concluded that the GNP had imparted the thermally and electrically conductive nature to the TPNR blend.

Matched MeSH terms: Tensile Strength
Fulltext Chicken gelatin films: rheological properties of film forming solutions and film characterisation as influenced by starch incorporation

Cheng, S. H., Sarbon, N. M.

International Food Research Journal, 2020;27(6):1094-1104.
MyJurnal

The aim of the present work was to develop chicken skin gelatin films incorporated with
different concentrations of rice starch prepared by casting techniques. Six film-forming
solutions were prepared separately with different blend ratios of chicken skin gelatin to rice
starch: A (0/100), B (5/100), C (10/100), D (15/100), E (20/100), and F (25/100). The
rheological properties of the film-forming solutions (FFS) were determined using frequency
sweep. The mechanical and physical properties of the respective films were also evaluated.
With the increase in rice starch concentration, the storage (G’) modulus of FFS increased
dramatically with loss (G”) modulus as the oscillatory frequency rising to contribute to gel
behaviour (G’ > G”). As rice starch concentration increased, the chicken skin gelatin films
also demonstrated higher tensile strength, elongation at break, and water vapour permeability,
but reduced the solubility of gelatin films in water. Additionally, elevation in melting point
values indicated that the thermal stability of the composite films was enhanced with the
increment of rice starch concentration. Film F (with 25% rice starch) yielded the optimal film
formulation, as it had the highest tensile strength and a high elongation at break value. Thus,
film F shows the best potential as a film for food packaging.

Matched MeSH terms: Tensile Strength
Fulltext Epoxidized vegetable oils plasticized poly(lactic acid) biocomposites: mechanical, thermal and morphology properties

Chieng BW, Ibrahim NA, Then YY, Loo YY

Molecules, 2014;19(10):16024-38.
PMID: 25299820 DOI: 10.3390/molecules191016024

Plasticized poly(lactic acid) PLA with epoxidized vegetable oils (EVO) were prepared using a melt blending method to improve the ductility of PLA. The plasticization of the PLA with EVO lowers the Tg as well as cold-crystallization temperature. The tensile properties demonstrated that the addition of EVO to PLA led to an increase of elongation at break, but a decrease of tensile modulus. Plasticized PLA showed improvement in the elongation at break by 2058% and 4060% with the addition of 5 wt % epoxidized palm oil (EPO) and mixture of epoxidized palm oil and soybean oil (EPSO), respectively. An increase in the tensile strength was also observed in the plasticized PLA with 1 wt % EPO and EPSO. The use of EVO increases the mobility of the polymeric chains, thereby improving the flexibility and plastic deformation of PLA. The SEM micrograph of the plasticized PLA showed good compatible morphologies without voids resulting from good interfacial adhesion between PLA and EVO. Based on the results of this study, EVO may be used as an environmentally friendly plasticizer that can improve the overall properties of PLA.

Matched MeSH terms: Tensile Strength
Fulltext Graphene nanoplatelets as novel reinforcement filler in poly(lactic acid)/epoxidized palm oil green nanocomposites: mechanical properties

Chieng BW, Ibrahim NA, Yunus WM, Hussein MZ, Giita Silverajah VS

Int J Mol Sci, 2012;13(9):10920-34.
PMID: 23109829 DOI: 10.3390/ijms130910920

Graphene nanoplatelet (xGnP) was investigated as a novel reinforcement filler in mechanical properties for poly(lactic acid) (PLA)/epoxidized palm oil (EPO) blend. PLA/EPO/xGnP green nanocomposites were successfully prepared by melt blending method. PLA/EPO reinforced with xGnP resulted in an increase of up to 26.5% and 60.6% in the tensile strength and elongation at break of the nanocomposites respectively, compared to PLA/EPO blend. XRD pattern showed the presence of peak around 26.5° in PLA/EPO nanocomposites which corresponds to characteristic peak of graphene nanoplatelets. However, incorporation of xGnP has no effect on the flexural strength and modulus. Impact strength of PLA/5 wt% EPO improved by 73.6% with the presence of 0.5 wt% xGnP loading. Mechanical properties of PLA were greatly improved by the addition of a small amount of graphene nanoplatelets (<1 wt%).

Matched MeSH terms: Tensile Strength
Fulltext The mechanical, thermal and morphological properties of graphene nanoplatelets filled poly(lactic acid)/epoxidized palm oil blends

Chieng, Buong Woei, Nor Azowa Ibrahim, Wan Md Zin Wan Yunus, Mohd Zobir Hussein

Scientific Research Journal, 2014;11(2):0-0.
MyJurnal

Poly(lactic acid) (PLA)-based nanocomposites filled with graphene nanoplatelets (xGnP) that contains epoxidized palm oil (EPO) as plasticizer were prepared by melt blending method. PLA was first plasticized by EPO to improve its flexibility and thereby overcome its problem of brittleness. Then, xGnP was incoporated into plasticized PLA to enhance its mechanical properties. Plasticized and nanofilled PLA nanocomposites (PLA/EPO/xGnP) showed improvement in the elongation at break by 3322% and 61% compared to pristine PLA and PLA/EPO, respectively. The use of EPO and xGnP increases the mobility of the polymeric chains, thereby improving the flexibility and plastic deformation of PLA. The nanocomposites also resulted in an increase of up to 26.5% in the tensile strength compared with PLA/EPO blend. XRD pattern showed the presence of peak around 26.5° in PLA/EPO/xGnP nanocomposites which corresponds to characteristic peak of graphene nanoplatelets. Plasticized PLA reinforced with xGnP showed that increasing the xGnP content triggers a substantial increase in thermal stability. Crystallinity of the nanocomposites as well as cold crystallization and melting temperature did not show any significant changes upon addition of xGnP. However, there was a significant decrease of glass transition temperature up to 0.3wt% of xGnP incorporation. The TEM micrograph of PLA/EPO/xGnP shows that the xGnP was uniformly dispersed in the PLA matrix and no obvious aggregation was observed.

Matched MeSH terms: Tensile Strength
New antimicrobial and collagen crosslinking formulated dentin adhesive with improved bond durability

Daood U, Omar H, Qasim S, Nogueira LP, Pichika MR, Mak KK, et al.

J Mech Behav Biomed Mater, 2020 10;110:103927.
PMID: 32957222 DOI: 10.1016/j.jmbbm.2020.103927

OBJECTIVE: Here we describe a novel formulation, based on quaternary ammonium (QA) and riboflavin (RF), which combines antimicrobial activities and protease inhibitory properties with collagen crosslinking without interference to bonding capabilities, was investigated.
METHODS: Experimental adhesives modified with different fractions of dioctadecyldimethyl ammonium bromide quaternary ammonium and riboflavin (QARF) were formulated. Dentine specimens were bonded to resincomposites with control or the experimental adhesives to be evaluated for bond strength, interfacial morphology, micro-Raman analysis, nano-CT and nano-leakage expression. In addition, the antibacterial and biocompatibilities of the experimental adhesives were investigated. The endogenous proteases activities and their molecular binding-sites were studied.
RESULTS: Modifying the experimental adhesives with QARF did not adversely affect micro-tensile bond strength or the degree of conversion along with the demonstration of anti-proteases and antibacterial abilities with acceptable biocompatibilities. In general, all experimental adhesives demonstrated favourable bond strength with increased and improved values in 1% QARF adhesive at 24 h (39.2 ± 3.0 MPa) and following thermocycling (34.8 ± 4.3 MPa).
SIGNIFICANCE: It is possible to conclude that the use of QARF with defined concentration can maintain bond strength values when an appropriate protocol is used and have contributed in ensuring a significant decrease in microbial growth of biofilms. Incorporation of 1% QARF in the experimental adhesive lead to simultaneous antimicrobial and anti-proteolytic effects with low cytotoxic effects, acceptable bond strength and interfacial morphology.

Matched MeSH terms: Tensile Strength
Novel riboflavin/VE-TPGS modified universal dentine adhesive with superior dentine bond strength and self-crosslinking potential

Daood U, Sauro S, Pichika MR, Omar H, Liang Lin S, Fawzy AS

Dent Mater, 2020 01;36(1):145-156.
PMID: 31818524 DOI: 10.1016/j.dental.2019.11.003

OBJECTIVE: To modify a universal dentine adhesive with different concentrations of riboflavin and D-Alpha 1000 Succinate polyethylene (VE-TPGS) as a chemical enhancer and to assess the micro-tensile bond strength (24h/12 months), determine resin penetration, measurement of intermolecular interactions and cytotoxicity.
MATERIALS AND METHODS: An experimental adhesive system based on bis-GMA, HEMA and hydrophobic monomer was doped with RF0.125 (RF - Riboflavin) or RF/VE-TPGS (0.25/0.50) and submitted to μTBS evaluation. Resin dentine slabs were prepared and examined using SEM and TEM. Adhesion force was analysed on ends of AFM cantilevers deflection. Quenched peptide assays were performed using fluorescence scanner and wavelengths set to 320nm and 405nm. Cytotoxicity was assessed using human peripheral blood mononuclear cell line. Molecular docking studies were carried out using Schrödinger small-molecule drug discovery suite 2018-2. Data from viable cell results was analyzed using one-way ANOVA. Bond strength values were analysed by two-way ANOVA. Nonparametric results were analyzed using a Kruskal-Wallis test at a 0.05 significance level.
RESULTS: RF/VE-TPGS0.25 groups showed highest bond strength results after 24-h storage in artificial saliva (p<0.05). RF/VE-TPGS0.50 groups showed increased bond strength after 12-months of ageing. RF/VE-TPGS modified adhesives showed appreciable presence of a hybrid layer. Packing fraction indicated solid angle profiles describing well sized density and topology relations for the RF/VE-TPGS adhesives, in particular with the RF/VE-TPGS0.50 specimens. Qualitative analysis of the phenotype of macrophages was prominently CD163+ in the RF/VE-TPGS0.50. Both the compounds showed favourable negative binding energies as expressed in terms of 'XP GScore'.
CONCLUSION: New formulations based on the incorporation of RF/VE-TPGS in universal adhesives may be of significant potential in facilitating penetration, distribution and uptake of riboflavin within the dentine surface.

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
Fulltext Fabrication of cellulose acetate film from oil palm empty fruit bunch (OP-EFB) and cytotoxicity evaluation

Dasmawati Mohamad, Wan Suzaini Wan Hamzah, Wan Rosli Wan Daud, Zainul Ahmad Rajion, Wan Zaripah Wan Bakar, Mazlan Ibrahim

Pertanika Journal of Science & Technology, 2012;20(1):189-207.
MyJurnal

The aims of this study were to fabricate cellulose acetate (CA) film from oil palm empty fruit bunch (OP-EPB), as well as to characterize and evaluate their biocompatibility. Several processes were carried out, and these included prehydrolysis-soda method, chlorine free bleaching method, including oxygen, ozone and peroxide, to produce the cellulose pulp. Then, a liquid phase acetylation method was applied through acetic acid-acetic anhydride-sulphuric acid. Triethyl citrate (TEC) ester was used as additive at different percentages of 10, 20, 30 and 40 wt%. The film produced was characterized by FTIR to identify the functional group of the CA film and their tensile properties were further characterized. Biocompatibility of the film was evaluated using cytotoxicity test. Stem cell derived from human deciduous teeth (SHED) was used with MTS assay. The results showed at 30% of TEC, the tensile strength and elongation of CA (OP-EFB) film was at the optimum and is therefore suitable to be used in dental application. The cytotoxicity evaluated showed that the fabricated CA (OP-EFB) films were non-toxic up to the concentration tested, and are thus compatible with SHED.

Matched MeSH terms: Tensile Strength
Fulltext Vulcanisation and coagulant dipping of epoxidised natural rubber latex

Dazylah Darji, Ma'zam Md Said

Pertanika Journal of Science & Technology, 2010;18(2):-.
MyJurnal

Epoxidised Natural Rubber (ENR) is now a commercially available polymer produced by chemical modification of natural rubber. Currently, three types of ENR are commercially available, and these are ENR 10, ENR 25, and ENR 50 with 10%, 25%, and 50% mol epoxidation, respectively. Studies on prevulcanisation of ENR 50 and postvulcanisation of the latex films were carried out. The objective of this study was to develop ENR 50 that could be dipped easily in coagulant dipping solution to produce dipped products. Several attempts were made by compounding prevulcanised ENR 50 at various sulphur levels ranging from 0.5 to 3.0 pphr. Using suitable coagulant dipping systems, ENR 50 film could be formed despite the high contents of non-ionic surfactant. It was found that the tensile strength of prevulcanised ENR 50 film decreased with the increase in the sulphur level. The results show that as level of sulphur increased, M300 also increased to an optimum value of 1.5 pphr of sulphur. For the postvulcanised ENR 50 film, however, the tensile strength increased and then decreased with the increasing sulphur level. Meanwhile M300 increased with the increasing postvulcanization time and sulphur level. The postvulcanisation of ENR 50 film seems to be a more effective way of increasing tensile properties than by prevulcanisation of ENR 50.

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
Fulltext Degradability enhancement of poly(lactic acid) by stearate-Zn(3)Al LDH nanolayers

Eili M, Shameli K, Ibrahim NA, Yunus WM

Int J Mol Sci, 2012;13(7):7938-51.
PMID: 22942682 DOI: 10.3390/ijms13077938

Recent environmental problems and societal concerns associated with the disposal of petroleum based plastics throughout the world have triggered renewed efforts to develop new biodegradable products compatible with our environment. This article describes the preparation, characterization and biodegradation study of poly(lactic acid)/layered double hydroxide (PLA/LDH) nanocomposites from PLA and stearate-Zn(3)Al LDH. A solution casting method was used to prepare PLA/stearate-Zn(3)Al LDH nanocomposites. The anionic clay Zn(3)Al LDH was firstly prepared by co-precipitation method from a nitrate salt solution at pH 7.0 and then modified by stearate anions through an ion exchange reaction. This modification increased the basal spacing of the synthetic clay from 8.83 Å to 40.10 Å. The morphology and properties of the prepared PLA/stearate-Zn(3)Al LDH nanocomposites were studied by X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscope (SEM), thermogravimetric analysis (TGA), tensile tests as well as biodegradation studies. From the XRD analysis and TEM observation, the stearate-Zn(3)Al LDH lost its ordered stacking-structure and was greatly exfoliated in the PLA matrix. Tensile test results of PLA/stearate-Zn(3)Al LDH nanocomposites showed that the presence of around 1.0-3.0 wt % of the stearate-Zn(3)Al LDH in the PLA drastically improved its elongation at break. The biodegradation studies demonstrated a significant biodegradation rate improvement of PLA in the presence of stearate-Zn(3)Al LDH nanolayers. This effect can be caused by the catalytic role of the stearate groups in the biodegradation mechanism leading to much faster disintegration of nanocomposites than pure PLA.

Matched MeSH terms: Tensile Strength
Fulltext Permanent deformation investigation of rubber polymer modified binder in superpave hot mix asphalt mixture

Ekarizan Shaffie1, Ahmad Kamil Arshad, Ramadhansyah Putra Jaya, Khairil Azman Masri, Wardati Hashim

Journal of Academia Universiti Teknologi MARA Negeri Sembilan, 2020;8(1):45-52.
MyJurnal

Moisture susceptibiltiy is one of the common types of pavement failure found in asphaltic pavements.
Climatic factor such as temperature and moisture has a profound effect on the durability of hot mix
asphalt pavements. Couple with high traffic loads/stresses made stripping of pavement materials
inevitable. Thus, it has become necessary to improve the efficiency of the design of hot mix asphalt
(HMA) for better performance and safe riding comfort. This study investigates and discusses the findings
on the stripping performance of dense graded Superpave mixes using two type of binder; un-modified
binder and rubber polymer modified binder (RPM) using Superpave mix design (AASHTO TP4)
procedure. The RPM binder consists of 4% of both rubber crumb and EVA polymer. Modified Lottman
and Resilient Modulus tests were used to evaluate the stripping performance in these mixtures and this
study also documents the effect of different temperature on tensile strength ratio (TSR) and resilient
modulus ratio (RMR) on the HMA mixtures. Experimental evidences show that the RPM binder mixes
were found to have significantly improved the resistance to moisture damage compared to unmodified
binder mixtures. The RPM binder application may able to alleviate problems related to aggregate
stripping and potholes on our road. Statistical analysis showed good correlation between resilient
modulus and tensile strength ratio.

Matched MeSH terms: Tensile Strength
Fulltext Impact strength and flexural properties enhancement of methacrylate silane treated oil palm mesocarp fiber reinforced biodegradable hybrid composites

Eng CC, Ibrahim NA, Zainuddin N, Ariffin H, Yunus WM

ScientificWorldJournal, 2014;2014:213180.
PMID: 25254230 DOI: 10.1155/2014/213180

Natural fiber as reinforcement filler in polymer composites is an attractive approach due to being fully biodegradable and cheap. However, incompatibility between hydrophilic natural fiber and hydrophobic polymer matrix restricts the application. The current studies focus on the effects of incorporation of silane treated OPMF into polylactic acid (PLA)/polycaprolactone (PCL)/nanoclay/OPMF hybrid composites. The composites were prepared by melt blending technique and characterize the composites with Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). FTIR spectra indicated that peak shifting occurs when silane treated OPMF was incorporated into hybrid composites. Based on mechanical properties results, incorporation of silane treated OPMF enhances the mechanical properties of unmodified OPMF hybrid composites with the enhancement of flexural and impact strength being 17.60% and 48.43%, respectively, at 10% fiber loading. TGA thermogram shows that incorporation of silane treated OPMF did not show increment in thermal properties of hybrid composites. SEM micrographs revealed that silane treated OPMF hybrid composites show good fiber/matrix adhesion as fiber is still embedded in the matrix and no cavity is present on the surface. Water absorption test shows that addition of less hydrophilic silane treated OPMF successfully reduces the water uptake of hybrid composites.

Matched MeSH terms: Tensile Strength
Salmon skin gelatin-corn zein composite films produced via crosslinking with glutaraldehyde: Optimization using response surface methodology and characterization

Fan HY, Duquette D, Dumont MJ, Simpson BK

Int J Biol Macromol, 2018 Dec;120(Pt A):263-273.
PMID: 30130612 DOI: 10.1016/j.ijbiomac.2018.08.084

Composite films comprised of salmon (Salmo salar) skin gelatin and zein were prepared via crosslinking with glutaraldehyde. Response surface methodology (RSM) was used to optimize film composition to maximize tensile strength (TS) and elongation at break (EAB), and to minimize water solubility (WS) of the films. The significant (P strength as a function of increasing humidity.

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

Filters

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

External Links