Effects of Ultrasound and Strain Rate on Tensile Mechanical Behavior of Thermoplastic Poly Urethane Thin Films

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Anandh Balakrishnan ◽  
Mrinal C. Saha
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Mechanical Test ◽  
Film Formation ◽  
Mechanical Tests ◽  
Scanning Calorimetry ◽  
Film Properties ◽  
Differential Scanning Calorimetry Scan ◽  
The Times ◽  
Specific Heat Capacities

Thermoplastic poly urethane (TPU) is a diblock copolymer which naturally phase segregates into thermodynamically incompatible hard (H) and soft (S) segments. The size of the segments and their spatial distribution can significantly affect the microstructure and mechanical properties of the material. In this paper, we investigated the effect of duration of exposure to ultrasound on the solution prior to film formation on the final film properties. The response variable for the study was primarily mechanical properties of the TPU thin films fabricated via a solution route utilizing tetra hydro furan as a solvent. The times of sonication were varied between 30 min and 90 min, while all films were fabricated at average thickness of 20 ± 5 μm. The mechanical tests have been conducted at two different displacement rates of 5 and 10 mm/min. Our results indicated that (relative to untreated TPU) ultrasound tends not to deteriorate the fracture strength, strain and yet improve the fracture toughness. We attribute these results to subtle events at the H and S segment/domain levels. To further understand these microstructural variations, we conducted differential scanning calorimetry scan tests between 25 °C and 200 °C at 5 °C/min on untested and tested TPU samples of all types. This data showed a delicate sonication time dependent trend and has been interpreted in conjunction with our mechanical test data. Transition temperatures, enthalpies, and specific heat capacities have been computed for these cases.

Effect of Ultrasound and Strain Rate on Tensile Behavior of Neat Thermoplastic Polyurethane Thin Films

2010 ◽  
Author(s):  
Anandh Balakrishnan ◽  
Mrinal C. Saha
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Strain Rate ◽  
Mechanical Test ◽  
Thermoplastic Polyurethane ◽  
Optical Element ◽  
Mechanical Tests ◽  
Primary Objective ◽  
Scanning Calorimetry ◽  
Rate Dependent

Thermoplastic Polyurethane (TPU) thin films have many applications in engineering and biomedical fields. Examples include moisture sensors, load cells, optical element and biocompatible stens. The TPU is a block copolymer naturally phase segregates into thermodynamically incompatible hard- and soft-segments. The size of the segments and their spatial distribution can significantly affect the microstructure and mechanical properties of the TPU. In this paper, we propose to investigate the effect of ultrasound energy on mechanical properties of TPU thin films fabricated via a solution route utilizing Tetra Hydro Furan (THF) as a solvent. The times of sonication was fixed at 60 minutes whilst all films were fabricated at average thickness of 20+/-5 um. The primary objective of the study was to understand the influence of ultrasound and strain rates on the material microstructure and the resulting mechanical properties. Mechanical tests have been conducted at two different displacement rates, namely 5 and 10 mm/min. Our preliminary results indicate that ultrasound improves the strength of the neat TPU films. We also see that strain hardening is displacement or strain rate dependent. We attribute these results to changes in the hard (H) and soft (S) domain structure. To further understand these microstructural variations, we propose to conduct Differential Scanning Calorimetry (DSC). The data has been interpreted in conjunction with our mechanical test data.

Effects of Steam Heat and Dry Heat Sterilization on Thermal and Mechanical Properties of Nylon and Policarbonate in Fabrication with Fused Filament

2021 ◽  
Vol 891 ◽  
pp. 150-163
Author(s):  
Jorge Mauricio Fuentes ◽  
Omar Flor Unda ◽  
Santiago Ferrandiz ◽  
Franyelit Suarez
Keyword(s):  
Mechanical Properties ◽  
Thermomechanical Analysis ◽  
Mechanical Tests ◽  
Effect Of Temperature ◽  
Mechanical And Thermal Properties ◽  
Scanning Calorimetry ◽  
Thermal Tests ◽  
Dry Heat ◽  
Izod Impact ◽  
Steam Heat

In this article presents evidence about performance of mechanical properties of polycarbonate and nylon materials, which are used in the additive manufacturing by deposition of molten material and that have been subjected to sterilization processes by moist heat at 121°C and dry heat at 140°C. This study provides useful information to consider the use of these materials in sanitary and sterile settings. Mechanical tests of tensile, flex, hardness, Izod impact, thermal tests in Differential Scanning Calorimetry DSC, Thermomechanical analysis TMA and Scanning Electron Microscopy SEM were performed. It is concluded that the mechanical and thermal properties have not been altered through the effect of temperature in sterilization processes.

Investigation of the Mechanical Properties of Thin Films by Bulge Test

2009 ◽  
Vol 156-158 ◽  
pp. 477-482
Author(s):  
Audrey Hémel ◽  
Alain Jacques ◽  
Thomas Schenk ◽  
Tomáš Kruml
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Room Temperature ◽  
Mechanical Tests ◽  
Bulge Test ◽  
Gold Films ◽  
Test Device

A new bulge test device has been built, with the aim to perform mechanical tests on membranes with a thickness in the 100 nm to 10 µm range, between room temperature and 900°C. The first tests on Si3N4 and gold films give results consistent with literature data.

Preparation and Mechanical Properties of Modified Magnesium Oxysulfate Cement Incorporating Alkali Conditioner

2020 ◽  
Vol 12 (10) ◽  
pp. 1558-1567
Author(s):  
Shengbin Li ◽  
Haoqian Ren ◽  
Qin Wu ◽  
Yiyang Ye
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Calcium Carbonate ◽  
Mechanical Test ◽  
Mechanical Tests ◽  
Molar Ratio ◽  
Buffer Solution ◽  
Magnesium Oxysulfate ◽  
Scanning Electron

Magnesium oxysulfate cement is an ecological gas-hardening cementitious material. The cement has a complex system, insufficient hydration, and unstable hydration products, so that the cement mechanical property is poor. In this study, calcium chloride/carbon dioxide/weak buffer solution is used to generate alkaline additive, namely vaterite calcium carbonate. The additive material is characterized by scanning electron microscopy and X-ray diffraction, and then the optimal MgO/MgSO4/H2O molar ratio after calcium carbonate is added to magnesium oxysulfate cement, the optimal laying method and reasonable amount of vaterite calcium carbonate are analyzed by mechanical tests. In the experiment, the basic additive is characterized firstly. It is found that the XRD of the additive mainly includes the peaks of calcite and vaterite. It can be seen by scanning electron microscopy that many calcites and vaterites are not formed, the calcites are accumulated more, and there is a large number of particles, which are not appeared before. In the mechanical test of magnesium sulfide cement, the mechanical properties of magnesium oxysulfate cement will increase firstly and then decrease with the increase of MgO/MgSO4 molar ratio in the way of long-cut calcium carbonate for reinforcement. Compared with the layout of long-cut calcium carbonate-magnesium oxysulfate cement, the layout of short-cut calcium carbonate-magnesium oxysulfate cement can enhance the toughness of the modified cement, increase the amount of calcium carbonate, and improve the flexural strength and toughness index of the modified magnesium oxysulfate cement. The blending ratio is better to be 6%. Based on above researches and demonstrations, blending the calcium carbonate-based alkaline additive can effectively improve the mechanical properties of the magnesium oxysulfate cement.

Effects of Bagasse Fiber on Crystallization, Morphological and Mechanical Properties of Poly(Lactic acid)

2012 ◽  
Vol 602-604 ◽  
pp. 708-711
Author(s):  
Jun Cai ◽  
Nan Shi ◽  
Qiang Dou
Keyword(s):  
Mechanical Properties ◽  
Flexural Modulus ◽  
Mechanical Tests ◽  
Silane Treatment ◽  
Melt Blending ◽  
Scanning Calorimetry ◽  
Crystallization Ability ◽  
The Matrix ◽  
Bagasse Fiber ◽  
Melting And Crystallization

Polylactic acid (PLA)/bagasse fiber (BF) composites were prepared via melt blending. The melting and crystallization behavior, morphology and mechanical properties of the composites were studied by means of differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and mechanical tests. The results indicate that the crystallization ability of PLA is improved with the addition of BF. Silane treatment improves the adhesion between BF and the matrix. Compared with pure PLA, the flexural modulus increases, while the notched impact strength decreases for BF/PLA composites.

Crystallization, Morphology and Mechanical Properties of PLA/PBAT/CaCO3 Composites

2012 ◽  
Vol 602-604 ◽  
pp. 768-771 ◽  
Author(s):  
Nan Shi ◽  
Jun Cai ◽  
Qiang Dou
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Crystallization Behavior ◽  
Mechanical Test ◽  
Poly Lactic Acid ◽  
Scanning Calorimetry ◽  
Crystallization Morphology ◽  
Morphology And Mechanical Properties ◽  
Scanning Electron

The melting, crystallization behavior, morphology and mechanical properties of poly(lactic acid) (PLA)/poly(butylene adipate-co-terephthalate) (PBAT)/calcium carbonate (CaCO3) composites were investigated by means of differential scanning calorimetry (DSC), scanning electron microscopy(SEM), and mechanical test. It is shown that PBAT decreases the crystallinity, while CaCO3 increases the crystallinity of the composites. A synergistic toughening effect is obtained by the combination of CaCO3 and PBAT. The optimum mechanical properties can be achieved in case of the composite (PLA: PBAT: CaCO3=60: 20: 20).

scholarly journals Reinforcing polypropylene with calcium carbonate of different morphologies and polymorphs

2018 ◽  
Vol 25 (4) ◽  
pp. 745-751 ◽  
Author(s):  
Yanwei Jing ◽  
Xueying Nai ◽  
Li Dang ◽  
Donghai Zhu ◽  
Yabin Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Calcium Carbonate ◽  
Mechanical Tests ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Crystallization Property ◽  
Reinforced Composite ◽  
Treated Sample ◽  
The Impact

Abstract The influence of calcium carbonate (CaCO3) with different polymorphs (calcite and aragonite) and morphologies (granular and rod-like) on mechanical and crystallization properties of polypropylene (PP) was investigated. Meanwhile, these CaCO3 fillers coated with oleic acid were added in different contents to PP. The results indicate that the tensile strength, flexural strength, modulus, and crystallization property of the filler-treated samples are improved, but the impact strength decreased. The crystallinity of the composites is higher than that of neat PP. Moreover, in the rod shape filler-treated sample, in both whisker species, the mechanical properties of composites are superior to the particles filled. Differential scanning calorimetry, X-ray diffraction, and mechanical tests display that calcite whisker-reinforced composite has higher crystallization enthalpy, melting enthalpy, degree of crystallinity, and mechanical properties than aragonite whiskers and calcite particles filled composites.

scholarly journals Transformation and Mechanical Properties of TiNi Thin Films Sputter Deposited at Various Argon Pressures for Micromachine Actuators

1999 ◽  
Vol 11 (4) ◽  
pp. 258-262
Author(s):  
Seiji Shimizu ◽  
◽  
Katsutoshi Kuribayashi
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Mechanical Properties ◽  
Differential Scanning Calorimetry ◽  
Shape Memory Alloy ◽  
Room Temperature ◽  
Tensile Tests ◽  
Alloy Thin Film ◽  
Scanning Calorimetry ◽  
Sputter Deposited

We studied the transformation and mechanical properties of Ti- 54.8-51.6 at % Ni shape memory alloy thin film actuators sputter-deposited at different argon pressures of 0.47-3.4 Pa. The higher the argon pressure, the lower the nickel composition. TiNi thin films were crystallized at 800C for 10min, aged at 400C for 6h, and analyzed by differential scanning calorimetry and tensile tests. All films showed 2-step transformation of martensite, R, and austenite phases. The maximum generative stress of 365MPa was obtained when the TiNi thin film actuator deposited at 2.0Pa was heated electrically to 30A/mm2 after deformation of 3.0% at room temperature.

scholarly journals Properties of 3D-printed wood sawdust-reinforced PLA composites

BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 5467-5480
Author(s):  
Nasir Narlıoğlu ◽  
Tufan Salan ◽  
Mehmet Hakkı Alma
Keyword(s):  
Mechanical Properties ◽  
Mechanical Test ◽  
Three Dimensional ◽  
Value Added ◽  
Polymeric Materials ◽  
Mechanical Tests ◽  
3D Printer ◽  
Pine Sawdust ◽  
Wood Sawdust ◽  
3D Printed

Thermal, morphological, and mechanical properties of three-dimensional (3D) printed polylactic acid (PLA) composites reinforced with different amounts of waste pine sawdust were investigated. To determine the mechanical properties of the obtained filaments, test samples were produced using a 3D printer according to the mechanical test standards. The filaments that were produced from blends that contained the wood sawdust at the highest level (20%) could be printed via a 3D printer without any problems. According to the results obtained from the mechanical tests, a decrease in the tensile strength values of the composites was observed with the addition of wood sawdust into the neat PLA polymer. On the other hand, it was determined that the flexural strength values of the wood sawdust/PLA composites significantly increased with the addition of the wood sawdust. It was concluded that the waste pine sawdust is a reasonable reinforcement material for the production of composite filament for 3D printing applications and it can be compatibly extruded with PLA polymer. Thus, sawdust can be used as a value-added waste source for the production of high-quality 3D polymeric materials.

Modification of biaxially oriented polypropylene films using dicyclopentadiene based hydrogenated hydrocarbon resin

2015 ◽  
Vol 35 (9) ◽  
pp. 859-866 ◽  
Author(s):  
Won-Suk Kong ◽  
Tae-Jun Ju ◽  
Jun-Hyo Park ◽  
Jae-Wook Lee ◽  
Ho Gyu Yoon
Keyword(s):  
Mechanical Properties ◽  
Oxygen Permeability ◽  
Amorphous Structure ◽  
High Glass Transition Temperature ◽  
Scanning Calorimetry ◽  
Film Properties ◽  
X Ray ◽  
Biaxially Oriented Polypropylene ◽  
Oriented Polypropylene ◽  
Polypropylene Films

Abstract The morphologies, crystalline structures, and thermal and rheological behaviors of isotactic polypropylene (iPP) blended with dicyclopentadiene based hydrogenated hydrocarbon resin (HCR) were investigated using scanning electron microscopy (SEM), wide-angle X-ray diffractometry, and differential scanning calorimetry in detail. Furthermore, the transparency, mechanical properties, and water vapor and oxygen permeability of biaxially oriented polypropylene films, fabricated from these iPP/HCR blends using a biaxial drawing machine, were examined. It was found that crystallinity varies with the HCR content of the iPP/HCR blend. In addition, amorphous HCR with its high glass transition temperature (Tg) upon blending with iPP’s amorphous structure affords improvements in various film properties, such as mechanical properties, transparency, and gas permeabilities.

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