scholarly journals The Role of Two-Step Blending in the Properties of Starch/Chitin/Polylactic Acid Biodegradable Composites for Biomedical Applications

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 592 ◽  
Author(s):  
Niyi Gideon Olaiya ◽  
Arif Nuryawan ◽  
Peter Kayode Oke ◽  
H. P. S. Abdul Khalil ◽  
Samsul Rizal ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Polylactic Acid ◽  
Biomedical Applications ◽  
Loss Modulus ◽  
Starch Content ◽  
Mechanical Analysis ◽  
Research Trend ◽  
Toxicity Tests ◽  
Distinct Peak ◽  
Peak Value

The current research trend for excellent miscibility in polymer mixing is the use of plasticizers. The use of most plasticizers usually has some negative effects on the mechanical properties of the resulting composite and can sometimes make it toxic, which makes such polymers unsuitable for biomedical applications. This research focuses on the improvement of the miscibility of polymer composites using two-step mixing with a rheomixer and a mix extruder. Polylactic acid (PLA), chitin, and starch were produced after two-step mixing, using a compression molding method with decreasing composition variation (between 8% to 2%) of chitin and increasing starch content. A dynamic mechanical analysis (DMA) was used to study the mechanical behavior of the composite at various temperatures. The tensile strength, yield, elastic modulus, impact, morphology, and compatibility properties were also studied. The DMA results showed a glass transition temperature range of 50 °C to 100 °C for all samples, with a distinct peak value for the loss modulus and factor. The single distinct peak value meant the polymer blend was compatible. The storage and loss modulus increased with an increase in blending, while the loss factor decreased, indicating excellent compatibility and miscibility of the composite components. The mechanical properties of the samples improved compared to neat PLA. Small voids and immiscibility were noticed in the scanning electron microscopy images, and this was corroborated by X-ray diffraction graphs that showed an improvement in the crystalline nature of PLA with starch. Bioabsorption and toxicity tests showed compatibility with the rat system, which is similar to the human system.

scholarly journals Enhancement of Mechanical and Dynamic Mechanical Properties of Hydrophilic Nanoclay Reinforced Polylactic Acid/Polycaprolactone/Oil Palm Mesocarp Fiber Hybrid Composites

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Chern Chiet Eng ◽  
Nor Azowa Ibrahim ◽  
Norhazlin Zainuddin ◽  
Hidayah Ariffin ◽  
Wan Md. Zin Wan Yunus ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Polylactic Acid ◽  
Oil Palm ◽  
Hybrid Composites ◽  
Loss Modulus ◽  
Impact Resistance ◽  
Dynamic Mechanical Properties ◽  
Mechanical Analysis ◽  
Dynamic Mechanical ◽  
The Fourier Transform

In previous studies, the effect of the addition of 1 wt% hydrophilic nanoclay on polylactic acid (PLA)/polycaprolactone (PCL)/oil palm mesocarp fiber (OPMF) biocomposites was investigated by tensile properties, thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). The current studies focus on the effect of addition of 1 wt% hydrophilic nanoclay on mechanical (flexural and impact properties) and dynamic mechanical properties of composites. The composites were characterized by the Fourier transform infrared spectroscopy (FTIR) and dynamic mechanical analysis (DMA). FTIR spectra show that peak shifting occurs when 1 wt% hydrophilic nanoclay was added to composites. The addition of 1 wt% hydrophilic nanoclay successfully improves the flexural properties and impact resistance of the biocomposites. The storage modulus of biocomposites was decreased when nanoclay was added which indicates that the stiffness of biocomposites was reduced. The loss modulus curve shows that the addition of nanoclay shift twotgin composites become closer to each other which indicates that the incorporation of nanoclay slightly compatibilizes the biocomposites. Tanδindicated that hybrid composites dissipate less energy compared to biocomposites indicate that addition of clay to biocomposites improves fiber/matrix adhesion. Water sorption test shows that the addition of nanoclay enhances water resistance of composites.

Dynamic Mechanical Analysis of Bio-Based and Synthetic Petroleum Based Polymer Foams with Powder Type Organic Filler at Prolonged Ultra-Violet Exposure

2020 ◽  
Vol 01 (01) ◽  
Author(s):  
M A Zulhakimie ◽  
◽  
Anika Zafiah M. Rus ◽  
N S S Sulong ◽  
A Syah Z A ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Epoxy Polymer ◽  
Loss Modulus ◽  
Ultra Violet ◽  
Mechanical Analysis ◽  
Uv Exposure ◽  
Polymer Foams ◽  
Polymer Foam ◽  
Powder Filler ◽  
Tan Δ

Wood powder filler applied to the bio-based and epoxy polymer foams has the potential to reinforce the polymer foam structure. The 'Meranti' wood filler type was used as the filler in this analysis. In order to observe the pore size of each sample when exposed to different hours of UV exposure using optical microscopy (OM), this study was made.This analysis was conducted to compare the mechanical properties of each sample with different filler ratios of 0 wt%, 5 wt%, 10 wt%, 15wt% and 20 wt% at different UV exposure hours, which is 0 hour to 6000 hours with a 2000 hour rapid increase. Using the DMA Q800 TA unit, the mechanical properties were studied. In order to obtain the product of their mechanical properties, samples having a scale of 40 x 10 x 5 mm were clamped into the machine. The results will show the value of tan δ, loss modulus and storage modulus from the DMA test.The tan δ value shows that the high tanδvalue will be produced by the higher ratio filler. In contrast to bio-based polymer foams, epoxy polymer foams with powder fillers have the highest tan δ value. It shows that the higher filler ratio can be reported with the lower tan δ value. As the filler ratio filler in the polymer foams increased, the consequence of storage and loss modulus was found to increase. The greater the modulus of loss and the modulus of storage, the lower the temperature. As energy is lost as heat during UV irradiation exposure, bio-based polymer foams with a high powder filler ratio can dissipate more energy.

scholarly journals Dynamic Mechanical Properties of Hybrid Layered Silicates/Kaolin Geopolymer Filler in Epoxy Composites

2017 ◽  
Vol 54 (3) ◽  
pp. 543-545 ◽  
Author(s):  
Yusrina Mat Daud ◽  
Kamarudin Hussin ◽  
Azlin Fazlina Osman ◽  
Che Mohd Ruzaidi Ghazali ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Speed ◽  
Hybrid Composites ◽  
Loss Modulus ◽  
Dynamic Mechanical Properties ◽  
Mechanical Analysis ◽  
Layered Silicates ◽  
Epoxy Composites ◽  
Damping Factor ◽  
Dynamic Mechanical

Preparation epoxy based hybrid composites were involved kaolin geopolymer filler, organo-montmorillonite at 3phr by using high speed mechanical stirrer. A mechanical behaviour of neat epoxy, epoxy/organo-montmorillonite and its hybrid composites containing 1-8phr kaolin geopolymer filler was studied upon cyclic deformation (three-point flexion mode) as the temperature is varies. The analysis was determined by dynamic mechanical analysis (DMA) at frequency of 1.0Hz. The results then expressed in storage modulus (E�), loss modulus (E�) and damping factor (tan d) as function of temperature from 40 oC to 130oC. Overall results indicated that E�, E�� and Tg increased considerably by incorporating optimum 1phr kaolin geopolymer in epoxy organo-montmorillonite hybrid composites.

scholarly journals Physical and Mechanical Properties of Ammonia-Treated Black Locust Wood

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 377 ◽  
Author(s):  
Mariana Domnica Stanciu ◽  
Daniela Sova ◽  
Adriana Savin ◽  
Nicolae Ilias ◽  
Galina A. Gorbacheva
Keyword(s):  
Mechanical Properties ◽  
Black Locust ◽  
Loss Modulus ◽  
Colour Change ◽  
Treated Wood ◽  
Physical And Mechanical Properties ◽  
Mechanical Analysis ◽  
Modulus Of Rupture ◽  
Elastic Behaviour ◽  
Control Samples

Because of the uneven colour of black locust wood, different technologies are used to change the colour, the bestknown being chemical and thermal treatments. Some of them affect the mechanical properties of wood, such as elasticity modulus, strength, durability. This study aims to compare the physical and mechanical properties of black locust wood control samples and treated wood samples with ammonia hydroxide, in terms of density profile, colour values (CIE L*, a*, b*), mechanical properties of samples subjected to static bending, viscous-elastic properties (storage modulus (E’), loss modulus (E”) and damping (tanδ)). Two types of ammonia-fuming treatment were applied on samples: first treatment T1-5% concentration of ammonia hydroxide for 30 days; second treatment T2-10% concentration for 60 days. The results highlighted the following aspects: the overall colour change in the case of the second treatment is 27% in comparison with 7% recorded for the control samples; the lightness and yellowness values are the most affected by the second ammonia treatment of black locust wood. The density increased with almost 20% due to ammonium fuming (10% concentration/60 days); in case of static bending, the elastic modulus (MOE) tends to decrease with increasing the exposure time to ammonium, but the modulus of rupture (MOR) increases with almost 17% and the breaking force increases too, with almost 41%. In the case of dynamic mechanical analysis, the temperature leads to different viscous-elastic behaviour of each type of samples.

Thermal stability and dynamic mechanical behavior of functional multiphase boride ceramics/epoxy composites

2019 ◽  
Vol 39 (6) ◽  
pp. 508-514
Author(s):  
Yannan He ◽  
Zhiqiang Yu
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Loss Modulus ◽  
Dynamic Mechanical Properties ◽  
Mechanical Analysis ◽  
Epoxy Composites ◽  
Scanning Calorimetry ◽  
Element Analysis ◽  
Reaction Heat ◽  
Dynamic Mechanical

Abstract The thermal and dynamic mechanical properties of epoxy composites filled with zirconium diboride/nano-alumina (ZrB2/Al2O3) multiphase particles were investigated by means of differential scanning calorimetry, dynamic thermo-mechanical analysis, and numerical simulation. ZrB2/Al2O3 particles were surface organic functional modified by γ-glycidoxypropyltrimethoxysilane for the improvement of their dispersity in epoxy matrix. The results indicated that the curing exotherm of epoxy resin decreased significantly due to the addition of ZrB2/Al2O3 multiphase particles. In comparison to the composites filled with unmodified particles, the modified multiphase particles made the corresponding filling composites exhibit lower curing reaction heat, lower loss modulus, and higher storage modulus. Generally speaking, the composites filled with 5 wt% modified multiphase particles presented the best thermal stability and thermo-mechanical properties due to the better filler-matrix interfacial compatibility and the uniform dispersity of modified particles. Finite element analysis also suggested that the introduction of modified ZrB2/Al2O3 multiphase particles increased the stiffness of the corresponding composites.

PLA-coated sisal fibre-reinforced polyester composite: Water absorption, static and dynamic mechanical properties

2018 ◽  
Vol 53 (1) ◽  
pp. 65-72 ◽  
Author(s):  
MK Gupta ◽  
Rohit Singh
Keyword(s):  
Mechanical Properties ◽  
Water Absorption ◽  
Loss Modulus ◽  
Alkali Treatment ◽  
Dynamic Mechanical Properties ◽  
Mechanical Analysis ◽  
Static Properties ◽  
Physical Treatment ◽  
Sisal Fibre ◽  
Dynamic Mechanical

In the present work, a novel physical treatment (PLA coating) of sisal fibres and its influence on the water absorption, static and dynamic mechanical properties of its composites has been presented. The treated sisal fibres were used consisted of alkali treatment and PLA coating to fabricate its polyester-based composites by hand lay-up technique keeping constant fibres content as 20 wt.% . Water absorption analysis was carried out in terms of water uptake (%), and sorption, diffusion and permeability coefficient. In addition, static properties were examined in terms of tensile, flexural and impact test, and dynamic mechanical analysis was performed in terms of storage modulus [Formula: see text], loss modulus [Formula: see text], damping [Formula: see text] and glass transition temperature [Formula: see text]. It was reported that the PLA-coated sisal composites showed the best performance in water absorption, mechanical and dynamic mechanical properties than pure sisal and alkali-treated sisal composites. There were 33%, 49%, 48%, and 27% improvement in water resistance, tensile strength, flexural strength and impact strength, respectively, of PLA-coated sisal composites as compared to that of pure sisal composite.

scholarly journals Enhancement of Mechanical and Thermal Properties of Polylactic Acid/Polycaprolactone Blends by Hydrophilic Nanoclay

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Chern Chiet Eng ◽  
Nor Azowa Ibrahim ◽  
Norhazlin Zainuddin ◽  
Hidayah Ariffin ◽  
Wan Md. Zin Wan Yunus ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Polylactic Acid ◽  
Mechanical Analysis ◽  
Basal Spacing ◽  
Mechanical And Thermal Properties ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
The Matrix ◽  
Thermal Stability Of

The effects of hydrophilic nanoclay, Nanomer PGV, on mechanical properties of Polylactic Acid (PLA)/Polycaprolactone (PCL) blends were investigated and compared with hydrophobic clay, Montmorillonite K10. The PLA/PCL/clay composites were prepared by melt intercalation technique and the composites were characterized by X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), Dynamic Mechanical Analysis (DMA), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM). FTIR spectra indicated that formation of hydrogen bond between hydrophilic clay with the matrix. XRD results show that shifting of basal spacing when clay incorporated into polymer matrix. TEM micrographs reveal the formation of agglomerate in the composites. Based on mechanical properties results, addition of clay Nanomer PGV significantly enhances the flexibility of PLA/PCL blends about 136.26%. TGA showed that the presence of clay improve thermal stability of blends. DMA show the addition of clay increase storage modulus and the presence of clay Nanomer PGV slightly shift two Tg of blends become closer suggest that the presence of clay slightly compatibilizer the PLA/PCL blends. SEM micrographs revealed that presence of Nanomer PGV in blends influence the miscibility of the blends. The PLA/PCL blends become more homogeneous and consist of single phase morphology.

Mechanical Properties of Coil Coating Evaluated with Dynamic Mechanical Analysis in Daul Cantilever

2007 ◽  
Vol 353-358 ◽  
pp. 1729-1732 ◽  
Author(s):  
Lei Chen ◽  
Hong Liang Pan
Keyword(s):  
Mechanical Properties ◽  
Dynamic Mechanical Analysis ◽  
Loss Modulus ◽  
Paint Layer ◽  
Mechanical Analysis ◽  
Curing Temperature ◽  
Mode Analysis ◽  
Dynamic Mechanical ◽  
Preparation Conditions ◽  
Coil Coating

The storage modulus, loss modulus, loss tangent (tanδ), stress and strain have been determined for painted steel specimens by dynamic mechanical analysis (DMA) operated in Dual Cantilever mode. Analysis of the composite system enabled the elastic modulus of the paint layer to be calculated and the result can be useful to analyze the mechanical properties of the coil coating. The calculation was found to be very sensitive to the geometry (especially thickness of the substrate and coating) and properties of the substrate and coating, leading to considerable variability in the calculated coating modulus. The DMA method was successful in detecting the glass transition temperature (Tg) as a peak in the tanδ curve. The value of Tg is sensitive to the preparation conditions (e.g. curing temperature) and composition of the paint. The results show that DMA in Dual Cantilever can be useful as a characterization tool for painted steel.

EFFECT OF POLYSULFANE SILANIZED SILICA ON THE MORPHOLOGY AND MECHANICAL PROPERTIES OF BROMBUTYL RUBBER VULCANIZATES

2013 ◽  
Vol 86 (4) ◽  
pp. 558-571 ◽  
Author(s):  
Jiyu Liang ◽  
Na Feng ◽  
Suqin Chang ◽  
C. Xinhong Wang ◽  
Guixia Zhang
Keyword(s):  
Mechanical Properties ◽  
High Speed ◽  
Loss Modulus ◽  
Mechanical Analysis ◽  
Relative Volume ◽  
Cross Link ◽  
Continuous Increase ◽  
Bound Rubber ◽  
Silanized Silica ◽  
Silica Dispersion

ABSTRACT Polysulfane silanized white silica particles were prepared by treating with various loadings of bis(3-trie-thoxysilylpropyl)tetrasulfide (TESPT) in a high-speed mixer. Brombutyl rubber (BIIR) vulcanizates filled with the silanized silica were prepared by compression molding. Compared with BIIR/untreated silica vulcanizate, the mechanical properties of BIIR/silanized silica vulcanizates improved prominently with the increase of TESPT loading and reached peak value with the TESPT loading increasing up to 2 phr but declined slightly with the continuous increment of the TESPT. Effects of various loadings of TESPT on the mechanical properties of BIIR vulcanizates were investigated by testing mechanical properties, vulcanizing properties, bound rubber, scanning electron microscopy, and dynamic mechanical analysis (DMA) to determine the extent of rubber-filler interaction. As shown in vulcanizing properties, bound rubber, and DMA measurements, the bound rubber content, cross-link density, and storage and loss modulus of BIIR vulcanizates clearly increased with the TESPT loading increasing from 0 to 2 phr and then reduced somewhat with a continuous increase of TESPT; the tanδmax value decreased significantly with the increment of TESPT loading from 0 to 2 phr and increased sharply with the TESPT content increasing to 4 phr. These experimental results indicate that the improvement in the mechanical properties of BIIR vulcanizates was mostly attributed to a strong BIIR–silica interaction and an effective dispersion of the silica. On the other hand, the decline of mechanical properties can be explained by the excess TESPT, as a kind of physical diluent, having an adverse effect on the silica dispersion and cross-link reaction. By forming the silica aggregates on the mixing, the poor dispersion of silica could cause the decline of relative volume content of silica in the matrix.

Structure, Microstructure, and Selected Mechanical Properties of Ti-Zr-Mo Alloys for Biomedical Applications

2014 ◽  
Vol 922 ◽  
pp. 75-80 ◽  
Author(s):  
Diego Rafael Nespeque Correa ◽  
Pedro Akira Bazaglia Kuroda ◽  
Carlos Roberto Grandini
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Biomedical Applications ◽  
Biomedical Application ◽  
Young's Modulus ◽  
Microstructural Analysis ◽  
Melting Furnace ◽  
High Hardness ◽  
Mechanical Analysis ◽  
Β Phase

New titanium alloys for biomedical applications have been developed primarily with the addition of Nb, Ta, Mo, and Zr, because those elements stabilize the β phase and they don’t cause cytotoxicity in the organism. The objective of this paper is to analyze the effect of molybdenum on the structure, microstructure, and selected mechanical properties of Ti-15Zr-xMo (x = 5, 10, 15, and 20 wt%) alloys. The samples were produced in an arc-melting furnace with inert argon atmosphere, and they were hot-rolled and homogenized. The samples were characterized using chemical, structural, and microstructural analysis. The mechanical analysis was made using Vickers microhardness and Young’s modulus measurements. The compositions of the alloys were sensitive to the molybdenum concentration, indicating the presence of α’+α”+β phases in the Ti-15Zr-5Mo alloy, α”+β in the Ti-15Zr-10Mo alloy, and β phase in the Ti-15Zr-15Mo and Ti-15Zr-20Mo alloys. The mechanical properties showed favorable values for biomedical application in the alloys presenting high hardness and low Young’s modulus compared with CP-Ti.

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