Full factorial experimental design for mechanical properties of electrospun vascular grafts

2017 ◽  
Vol 47 (6) ◽  
pp. 1378-1391 ◽  
Author(s):  
Ipek Y Enis ◽  
Hande Sezgin ◽  
Telem G Sadikoglu
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Rotational Speed ◽  
Fiber Orientation ◽  
Vascular Grafts ◽  
Single Layer ◽  
Elongation At Break ◽  
Full Factorial ◽  
Polymer Type ◽  
Scanning Electron

In this study, single layer vascular grafts were produced by a custom designed electrospinning apparatus. Both polymer type and rotational speed of the rotating collector were varied in single layer designs. Surface morphology of the fibrous scaffolds was observed under scanning electron microscope. Fiber diameter was measured and fiber orientation was analyzed by Image J Software. Scanning electron microscope images and fiber orientation analysis results indicated that fiber orientation was improved with increased rotational speed. Ultimate tensile strength and elongation at break values of the scaffolds were tested in planar forms. In addition to the experimental analysis, statistical analysis was also realized; 22 full factorial design was adapted to the test results in order to investigate the effect of polymer type and the rotational speed on elongation at break and ultimate tensile strength values. Results have shown that both polymer type and the rotational speed of the collector significantly influenced ultimate tensile strength and elongation at break values of scaffolds tested in the radial direction. When the scaffolds tested in the horizontal direction were considered, while both factors have had a poor effect on ultimate tensile strength, they were either significant or were very close to the confidence limits. On the other hand, the interaction effect of factors had a statistically significant influence on mechanical properties of both testing directions. The achieved results supported by statistical analysis can provide a reference for further studies in designing multilayer vascular grafts.

Tensile Properties of Polypropylene/Cocoa Pod Husk Biocomposites: Effect of Maleated Polypropylene

2013 ◽  
Vol 747 ◽  
pp. 645-648 ◽  
Author(s):  
Koay Seong Chun ◽  
Salmah Husseinsyah ◽  
Hakimah Osman
Keyword(s):  
Tensile Strength ◽  
Tensile Properties ◽  
Tensile Modulus ◽  
Melt Blending ◽  
Elongation At Break ◽  
Maleated Polypropylene ◽  
Matrix Interaction ◽  
Cocoa Pod Husk ◽  
Blending Process ◽  
Scanning Electron

Polypropylene/Cocoa Pod Husk (PP/CPH) biocomposites with different maleated polypropylene (MAPP) content were prepared via melt blending process using Brabender Plastrograph mixer. The tensile strength and tensile modulus of PP/CPH biocomposites increased with increasing of MAPP content. The PP/CPH biocomposites with 5 phr of MAPP showed the optimum improvement on tensile properties. However, the increased of MAPP content reduced the elongation at break of PP/CPH biocomposites. At 5 phr of MAPP content, PP/CPH biocomposites showed lowest elongation at break. Scanning electron microscope confirms the PP/CPH biocomposites with MAPP have better filler-matrix interaction and adhesion due to the effect of MAPP.

scholarly journals Preparation, properties and applications of wheat gluten edible films

2000 ◽  
Vol 9 (1) ◽  
pp. 23-35 ◽  
Author(s):  
P. TANADA-PALMU ◽  
H. HELÉN ◽  
L. HYVÖNEN
Keyword(s):  
Weight Loss ◽  
Tensile Strength ◽  
Water Vapor ◽  
Wheat Gluten ◽  
Single Layer ◽  
Water Vapor Permeability ◽  
Edible Films ◽  
Bilayer Film ◽  
Vapor Permeability ◽  
Elongation At Break

Edible films from wheat gluten were prepared with various amounts of glycerol as a plasticizer. Water vapor permeability, oxygen permeability, tensile strength and percentage elongation at break at different water activities ( aw ) were measured. Films with low amounts of glycerol had lower water vapor and oxygen permeabilities, higher tensile strength and lower elongation at break. Wheat gluten coatings reduced weight loss during two weeks of storage for cherry tomatoes and sharon fruits compared to uncoated controls. A bilayer film of wheat gluten and beeswax significantly lowered weight loss from coated cheese cubes compared to single layer coating of wheat gluten.;

Mechanical Properties of Herbal Patches from Chitosan-Based Polymer Blends for Medical Applications

2018 ◽  
Vol 917 ◽  
pp. 52-56
Author(s):  
Jirapornchai Suksaeree
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Polymer Blends ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Hydroxypropyl Methylcellulose ◽  
Peel Strength ◽  
Elongation At Break ◽  
Zingiber Cassumunar

Recently, Thai herbs are widely used as medicine to treat some illnesses. Zingiber cassumunar Roxb., known by the Thai name “Plai”, is a popular anti-inflammatory, antispasmodic herbal body and muscle treatment. This research aimed to prepare herbal patches that incorporated the 3 g of crude Z. cassumunar oil. The herbal patches made from different polymer blends were 2 g of 3.5%w/v chitosan and 5 g of 20%w/v hydroxypropyl methylcellulose (HPMC), or 2 g of 3.5%w/v chitosan and 5 g of 20%w/v polyvinyl alcohol (PVA) using 2 g of glycerin as a plasticizer. They were prepared by mixing all ingredients in a beaker and produced by solvent casting method in hot air oven at 70±2oC. The completed herbal patches were evaluated for their mechanical properties including Young’s modulus, ultimate tensile strength, elongation at break, T-peel strength, and tack adhesion. The thickness of blank and herbal patches was 0.263-0.282 mm and 0.269-0.275 mm, respectively. Young’s modulus, ultimate tensile strength, elongation at break, T-peel strength, and tack adhesion were 104.73-142.71 MPa, 87.92-93.28 MPa, 154.39-174.98 %, 3.43-4.88 MPa, and 5.29-7.02 MPa, respectively, for blank patches, and 116.83-147.28 MPa, 89.49-100.47 MPa, 133.78-159.27 %, 2.01-3.98 MPa, and 4.03-5.19 MPa, respectively, for herbal patches. We prepared herbal blended patches made from chitosan/PVA or chitosan/HPMC polymer matrix blends incorporating the crude Z. cassumunar oil. They had good mechanical properties that might be developed for herbal medicinal application.

Development of New Polymers from Thevetia peruviana Oil

2020 ◽  
Vol 48 ◽  
pp. 9-23 ◽  
Author(s):  
Adebayo F. Owa ◽  
Isiaka O. Oladele ◽  
Adeolu Adesoji Adediran ◽  
Joseph A. Omotoyinbo
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Cationic Polymerization ◽  
Boron Trifluoride ◽  
Seed Oil ◽  
Polymeric Materials ◽  
Boron Trifluoride Etherate ◽  
Elongation At Break ◽  
Synthesized Materials ◽  
The Impact

Three novel bio-polymers were synthesized by cationic polymerization of Thevetia peruviana seed oil with styrene and divinylbenzene using modified boron trifluoride etherate as initiator. The cured thermosets ranging from soft to hard, were found to contain between 74.8 to 85.5 % cross linked materials with crosslink densities ranging from 1.33 x 103 to 1.84 x 103 mol/m3. The ultimate tensile strength of the materials varied from 0.52 to 0.55 Mpa, the young moduli is between 38.4 to 53.9 Mpa, the elongation at break varied from 55 to 64 %, the density of the polymers ranged between 0.850 to 0.866 gcm-3, the impact strength is between 2.31 to 2.81 J, while hardness ranged between 3.40 to 3.90 BHN. Overall, the newly synthesized materials from Thevetia peruviana oil have many potentials as new polymeric materials.

Development of Alginate Based Active Films Containing Turmeric Essential Oil

2020 ◽  
Vol 861 ◽  
pp. 378-382
Author(s):  
Sophoan Phal ◽  
Muhammad Rafiullah Khan ◽  
Pattarin Leelaphiwat ◽  
Vanee Chonhenchob
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Tensile Strength ◽  
Water Vapor ◽  
Essential Oil ◽  
Sem Analysis ◽  
Film Properties ◽  
Elongation At Break ◽  
Control Film ◽  
Scanning Electron

Sodium alginate based films containing turmeric oil (TEO) at different concentrations (1, 2 and 3%) were developed. The film with no TEO was used as control. Incorporation of TEO had the effects on the film properties. With increasing TEO concentrations, thickness, elongation at break, permeability of oxygen and water vapor of the films significantly (p ≤ 0.05) increased. Whereas moisture content, tensile strength and modulus of elasticity significantly (p ≤ 0.05) decreased. Scanning electron microscopy (SEM) analysis showed more numerous pores and rougher surface of the antifungal films than the control film.

scholarly journals Splitting of Islands-in-the-Sea Fibers (PA6/COPET) during Hydroentangling of Nonwovens

2007 ◽  
Vol 2 (4) ◽  
pp. 155892500700200 ◽  
Author(s):  
Mbwana Suleiman Ndaro ◽  
Xiang-yu Jin ◽  
Ting Chen ◽  
Chong-wen Yu
Keyword(s):  
Tensile Strength ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Water Jet ◽  
Elongation At Break ◽  
Sem Micrographs ◽  
Fiber Splitting ◽  
Data Analyses ◽  
Scanning Electron

This paper summarizes the investigations of hydroentangled islands-in-the-sea (PA6/COPET) fiber webs. An increase in water jet pressure improved the tensile strength and fiber splitting while elongation at break decreased. Scanning Electron Microscope (SEM) micrographs and ANOVA (MS Excel ™) were used for characterizing fiber splitting and data analyses respectively. It can be concluded that with a new innovation in spinnerette design and modification of co-polyester structure, PA6/COPET, fibers can be split in the hydroentanglement process without dissolution of the sea component.

Effect of Mo and Bi on Mechanical Properties of Zr-Fe-Cr Alloy at Room Temperature

2013 ◽  
Author(s):  
B. F. Luan ◽  
L. Q. Yang ◽  
T. G. Wei ◽  
K. L. Murty ◽  
C. S. Long ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Electron Microscope ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Room Temperature ◽  
Mechanical Performance ◽  
Microstructure Observation ◽  
Scanning Electron ◽  
Zr Alloy

To investigate the effects of Mo and Bi on mechanical properties of a Zr-Fe-Cr alloy at room temperature, seven Zr-Fe-Cr-Mo-Bi alloys with different compositions were designed. They were subjected to a series of rolling processes and heat treatments, and then sampled to measure mechanical properties by hardness and tensile test and to characterize microstructures by scanning electron microscope (SEM) and electron channel contrast (ECC) technique. Results indicated that among them two types of Zr-Fe-Cr-Mo-Bi alloys achieve the designed goals on mechanical properties and have the following advantages: (i) the hardness of the alloys, up to 334HV after annealing, is 40% higher than traditional Zr-4. (ii) The yield strength (YS) and ultimate tensile strength (UTS) of the alloys are 526 MP a and 889 MP a after hot rolling and annealing, markedly higher than the traditional Zr alloy. (iii) Good plasticity of the new Zr-Fe-Cr-Mo-Bi alloy is obtained with about 40% elongation, which is greatly higher than the Zr-Fe-Cr-Mo alloy thanks to the addition of Bi offsetting the disadvantage of addition Mo. Furthermore, according to observations of the microstructure observation, the reasons of the effect of the Mo and Bi elements on the mechanical performance of Zr-Fe-Cr alloy were studied and discussed.

The post-morphological analysis of electrospun vascular grafts following mechanical testing

2018 ◽  
Vol 38 (6) ◽  
pp. 525-535 ◽  
Author(s):  
Ipek Yalcin Enis ◽  
Telem Gok Sadikoglu ◽  
Jana Horakova ◽  
David Lukas
Keyword(s):  
Mechanical Properties ◽  
Cardiovascular Diseases ◽  
Production Technology ◽  
Vascular Graft ◽  
Morphological Analysis ◽  
Vascular Grafts ◽  
Single Layer ◽  
Composite Effect ◽  
Polymer Type ◽  
Morphology And Mechanical Properties

AbstractVascular grafts provide promising scaffolds for patients recuperating from cardiovascular diseases. Since it is necessary to mimic the native vessel in order to overcome the limitations of currently employed synthetic prostheses, researchers are tending to focus on the design of electrospun biodegradable multi-layer scaffolds which involves varying either the polymer type or constructional properties in each layer which, in turn, reveals the importance of layer interactions and their composite effect on the final multi-layer graft. This study describes the fabrication of biodegradable single-layer tubular scaffolds from polycaprolactone and poly(L-lactide)caprolactone polymers composed of either randomly distributed or, preferably, radially oriented fibers. Subsequently, bi-layer scaffolds were fabricated with a randomly distributed inner layer and a radially oriented outer layer from various polymer couple variations. The study focuses on vascular graft production technology including its morphology and mechanical properties. The post-morphologies of single-layer and bi-layer tubular scaffolds designed for vascular grafts were investigated as a continuation of a previously performed analysis of their mechanical properties. The results indicate that the mechanical properties of the final bi-layer grafts were principally influenced by the radially oriented outer layers acting as thetunica mediaof the native vessels when the appropriate polymer couples were chosen for the sub-layers.

Effect of Process Parameters on Defect Formation in Friction Stir Processed 6082-T6 Aluminium Alloy

2012 ◽  
Vol 232 ◽  
pp. 3-7
Author(s):  
Akinlabi Esther Titilayo ◽  
Akinlabi Stephen Akinwale
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Aluminium Alloy ◽  
Process Parameters ◽  
Friction Stir Processing ◽  
Feed Rate ◽  
Rotational Speed ◽  
Defect Formation ◽  
Processing Parameters ◽  
Friction Stir

This paper reports the effects of processing parameters on defects formed during friction stir processing of 6082-T6 Aluminium Alloy. The plates were processed by varying the feed rate between 50 and 250 mm/min, while the rotational speed was varied between 1500 and 3500 rpm to achieve the best result. It was observed that the sheets processed at the highest feed rate considered in this research resulted in wormhole defect. These processed samples with defects were correlated to the tensile results and it was found that the Ultimate Tensile Strength (UTS) of these samples was relatively low compared to other samples without defects.

Multiple Reprocessing of Gear Using Recycled Polypropylene

2014 ◽  
Vol 660 ◽  
pp. 204-208
Author(s):  
Nik Mizamzul Mehat ◽  
Amirul Aliff Jamaludin ◽  
Shahrul Kamaruddin
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Tensile Properties ◽  
Spur Gear ◽  
Spur Gears ◽  
Elongation At Break ◽  
Recycled Polypropylene ◽  
Gear Manufacturing ◽  
Multiple Processing ◽  
Satisfactory Quality

The reprocessing ability of recycled polypropylene (PP) has been investigated to evaluate the recycling feasibility in spur gear production. Up to 15 reprocessing cycles have been performed by injection moulding, and the effects on tensile properties including ultimate tensile strength, Young’s modulus and elongation at break have been studied. Results revealed that reprocessing ability of recycled PP spur gears could yield satisfactory quality as attractive as that corresponding to the virgin PP spur gear. The recycled PP gears resulted in more 10% variation in tensile properties during multiple processing. This effort might be a contribution to convince the industry to apply recycling of PP by means of multiple reprocessing in gear manufacturing.

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