scholarly journals The Mechanical Properties of PVC Nanofiber Mats Obtained by Electrospinning

Fibers ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 2
Author(s):  
Quoc Pham Le ◽  
Mayya V. Uspenskaya ◽  
Roman O. Olekhnovich ◽  
Mikhail A. Baranov
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Thermogravimetric Analysis ◽  
Thermal Degradation ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Nanofiber Mats

This paper investigates the mechanical properties of oriented polyvinyl chloride (PVC) nanofiber mats, which, were obtained by electrospinning a PVC solution. PVC was dissolved in a solvent mixture of tetrahydrofuran/dimethylformamide. Electrospinning parameters used in our work were, voltage 20 kV; flow rate 0.5 mL/h; the distance between the syringe tip and collector was 15 cm. The rotating speed of the drum collector was varied from 500 to 2500 rpm with a range of 500 rpm. Nanofiber mats were characterized by scanning electron microscope, thermogravimetric analysis, differential scanning calorimetry methods. The mechanical properties of PVC nanofiber mats, such as tensile strength, Young’s modulus, thermal degradation, and glass transition temperature were also analyzed. It was shown that, by increasing the collector’s rotation speed from 0 (flat plate collector) to 2500 rpm (drum collector), the average diameter of PVC nanofibers decreased from 313 ± 52 to 229 ± 47 nm. At the same time, it was observed that the mechanical properties of the resulting nanofiber mats were improved: tensile strength increased from 2.2 ± 0.2 MPa to 9.1 ± 0.3 MPa, Young’s modulus from 53 ± 14 to 308 ± 19 MPa. Thermogravimetric analysis measurements showed that there was no difference in the process of thermal degradation of nanofiber mats and PVC powders. On the other hand, the glass transition temperature of nanofiber mats and powders did show different values, such values were 77.5 °C and 83.2 °C, respectively.

scholarly journals Experimental Cold-Cured Nanostructured Epoxy-Based Hybrid Formulations: Properties and Durability Performance

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 476 ◽  
Author(s):  
Mariaenrica Frigione ◽  
Mariateresa Lettieri ◽  
Francesca Lionetto ◽  
Leno Mascia
Keyword(s):  
Mechanical Properties ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Thermogravimetric Analysis ◽  
Low Temperature ◽  
Thermal Degradation ◽  
Ambient Temperature ◽  
Durability Performance ◽  
Different Levels

Different hybrid epoxy formulations were produced and cold-cured, monitoring the properties development during low temperature curing and aging. All systems were based on silane functionalized bis-phenol A (DGEBA) resins (Part A), cured at ambient temperature with two amine hardeners (Part B). The different components of the formulations were selected on their potential capability to bring about enhancements in the glass transition temperature. The durability of the produced hybrids was probed in comparison to the corresponding neat epoxies by monitoring changes in glass transition temperature (Tg) and flexural mechanical properties after exposure to different levels of humidity and immersion in water and at temperatures slightly higher than the local ambient temperature, in order to simulate the conditions encountered during summer seasons in very humid environments. The thermal degradation resistance of the hybrid systems was also evaluated by thermogravimetric analysis.

Development of Young's modulus of natural illitic clay during the heating and cooling stages of firing

Clay Minerals ◽  
2019 ◽  
Vol 54 (3) ◽  
pp. 229-233 ◽  
Author(s):  
Tomáš Húlan ◽  
Igor Štubňa ◽  
Andrei Shishkin ◽  
Jurijs Ozolins ◽  
Štefan Csáki ◽  
...  
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Bound Water ◽  
Thermomechanical Analysis ◽  
X Ray Diffraction ◽  
Heating And Cooling ◽  
Thermal Expansion Coefficients

AbstractIllitic clay from the locality of Liepa, Latvia, was investigated using dynamic thermomechanical analysis during the heating and cooling stages of firing. Differential thermal analysis, thermogravimetry, thermodilatometry, X-ray diffraction and porosimetry were also performed to shed light on the processes influencing the elastic properties of clay. The increase in the Young's modulus (YM) at low temperatures was linked to the release of physically bound water. Above 850°C, the bulk density and YM both increased as a consequence of sintering. The YM was more sensitive to the progress of sintering compared to dimension changes. The YM values continued to increase during cooling until the glass-transition temperature was reached. At this temperature, the first microcracks caused by the differences in thermal expansion coefficients of the present phases were expected to appear. The YM showed a sharp V-shaped minimum at the β → α transition of quartz, which was a result of alternation of the mechanical radial stresses around the quartz grains. When the transition of quartz was completed, the YM continued to decrease because microcracks were still being created at the boundaries between the different phases. The decrease of the YM during cooling from the glass-transition temperature down to room temperature was ~50% for all of the firing temperatures and isothermal periods applied.

Microstructures and Mechanical Properties of Melt Spinning Spandex

2014 ◽  
Vol 1048 ◽  
pp. 36-40
Author(s):  
Wei Lai Chen ◽  
Lin Yan Wan ◽  
Hong Qin
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Heat Treatment ◽  
Scanning Electron Microscopy ◽  
Tensile Strength ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Melt Spinning ◽  
Scanning Electron

Microstructures and mechanical properties of melt spinning spandex were studied in this article.Cross section and longitudinal surface were observed and analyzed by JSM-5610LV scanning electron microscopy. Q2000 DSC differential scanning calorimeter was used to test the glass transition temperature and melting temperature which indicated glass transition temperature is about 44°C and melting temperature is about 200°C. We employed JSM-5610LV scanning electron microscopy to observe adhesion of melt spinning spandex with nylon filament after different time and temperature processing. It concluded that after 150°C90s、160°C60s、160°C90s、170°C30s heat treatment, the adhesive of melt spinning spandex with nylon is good. At the same time,tensile strength and elastic properties of melt spinning spandex which was processed under different time and temperature were tested, tensile strength and elastic recovery of melt spinning spandex after160°C 90s heat treatment is the best.

scholarly journals Multi-Material Additive Manufacturing of Sustainable Innovative Materials and Structures

Polymers ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 62 ◽  
Author(s):  
Rupinder Singh ◽  
Ranvijay Kumar ◽  
Ilenia Farina ◽  
Francesco Colangelo ◽  
Luciano Feo ◽  
...  
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Additive Manufacturing ◽  
Glass Transition Temperature ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Peak Load ◽  
Fused Deposition Modelling ◽  
Fused Deposition ◽  
Innovative Materials

This paper highlights the multi-material additive manufacturing (AM) route for manufacturing of innovative materials and structures. Three different recycled thermoplastics, namely acrylonitrile butadiene styrene (ABS), polylactic acid (PLA), and high impact polystyrene (HIPS) (with different Young’s modulus, glass transition temperature, rheological properties), have been selected (as a case study) for multi-material AM. The functional prototypes have been printed on fused deposition modelling (FDM) setup as tensile specimens (as per ASTM D638 type-IV standard) with different combinations of top, middle, and bottom layers (of ABS/PLA/HIPS), at different printing speed and infill percentage density. The specimens were subjected to thermal (glass transition temperature and heat capacity) and mechanical testing (peak load, peak strength, peak elongation, percentage elongation at peak, and Young’s modulus) to ascertain their suitability in load-bearing structures, and the fabrication of functional prototypes of mechanical meta-materials. The results have been supported by photomicrographs to observe the microstructure of the analyzed multi-materials.

Investigation of Thermoplastic Starch/Fiber Blend: Effect of Tapioca Residue on the Mechanical Properties and Surface Study

2017 ◽  
Vol 873 ◽  
pp. 123-127
Author(s):  
Yupawan Thongjun ◽  
Thiti Kaisone ◽  
Pran Hanthanon ◽  
Chanon Wiphanurat ◽  
Sumate Ouipanich ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Polymer Matrix ◽  
Corn Starch ◽  
Thermoplastic Starch ◽  
Compression Molding ◽  
Reinforcing Effect

The aim of this study was to characterize thermoplastic starch containing corn starch and tapioca residues, which were used as reinforcement in a blended matrix. In the process, the composites were prepared with different tapioca residue contents at 20, 30, 40, 50 and 60 % by weight using compression molding at 135 °C for 8 min. Subsequently, their mechanical, thermal and morphology properties were evaluated. The results showed that the reinforcing effect of tapioca residue lead an increase in the stiffness of the samples. Young’s modulus increased with higher tapioca residue content. When the loading of tapioca residue increased tensile strength for 80/20 and 70/30 mixtures from 7.46 to 8.58 MPa. In addition to the highest of tapioca residue could increase tensile strength dramatically. Further, the glass transition temperature tended to decrease with the increased loading of tapioca residue. Moreover, the morphology showed that the increment of tapioca residue content appeared embedded in the polymer matrix.

Development of technology of polysulfone production for 3D printing

2017 ◽  
Vol 29 (6) ◽  
pp. 724-729 ◽  
Author(s):  
Azamat A Zhansitov ◽  
Svetlana Y Khashirova ◽  
Azamat L Slonov ◽  
Zhanna I Kurdanova ◽  
Albert S Shabaev ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
3D Printing ◽  
Thermal Degradation ◽  
Strength Properties ◽  
Cross Linking ◽  
Molten Polymer ◽  
Chain Rigidity

This article discusses the results of experimental research on the synthesis of polyether sulfones and the molten polymer filament layering 3-D printing technology. The regularities of influence of the polycondensation conditions in the synthesis of polyphenylene sulfone on the processes of cross-linking, thermal degradation of the polymer at processing temperatures, and 3-D printing were revealed. It is shown that introduction of cardo fragments increases the glass transition temperature and heat resistance of the copolymers, and the elastic-strength properties, due to the increased chain rigidity. It determined the influence of technological modes of 3-D printing by layering molten polymer filaments on the physico-mechanical properties of polyether sulfones.

scholarly journals Studies on the Modification of Commercial Bisphenol-A-Based Epoxy Resin Using Different Multifunctional Epoxy Systems

2021 ◽  
Vol 2 (2) ◽  
pp. 419-430
Author(s):  
Ankur Bajpai ◽  
James R. Davidson ◽  
Colin Robert
Keyword(s):  
Mechanical Properties ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Bisphenol A ◽  
Epoxy Resin ◽  
Tensile Fracture ◽  
Chemical Structures ◽  
Amino Phenol ◽  
Epoxy Systems

The tensile fracture mechanics and thermo-mechanical properties of mixtures composed of two kinds of epoxy resins of different chemical structures and functional groups were studied. The base resin was a bi-functional epoxy resin based on diglycidyl ether of bisphenol-A (DGEBA) and the other resins were (a) distilled triglycidylether of meta-amino phenol (b) 1, 6–naphthalene di epoxy and (c) fluorene di epoxy. This research shows that a small number of multifunctional epoxy systems, both di- and tri-functional, can significantly increase tensile strength (14%) over neat DGEBA while having no negative impact on other mechanical properties including glass transition temperature and elastic modulus. In fact, when compared to unmodified DGEBA, the tri-functional epoxy shows a slight increase (5%) in glass transition temperature at 10 wt.% concentration. The enhanced crosslinking of DGEBA (90 wt.%)/distilled triglycidylether of meta-amino phenol (10 wt.%) blends may be the possible reason for the improved glass transition. Finally, the influence of strain rate, temperature and moisture were investigated for both the neat DGEBA and the best performing modified system. The neat DGEBA was steadily outperformed by its modified counterpart in every condition.

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