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 ◽  
...  

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.

Fibers ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 2
Author(s):  
Quoc Pham Le ◽  
Mayya V. Uspenskaya ◽  
Roman O. Olekhnovich ◽  
Mikhail A. Baranov

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.


Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 476 ◽  
Author(s):  
Mariaenrica Frigione ◽  
Mariateresa Lettieri ◽  
Francesca Lionetto ◽  
Leno Mascia

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.


Author(s):  
M. I. Valueva ◽  
I. V. Zelenina ◽  
M. A. Zharinov ◽  
M. A. Khaskov

The article presents results of studies of experimental carbon plastics based on thermosetting PMRpolyimide binder. Сarbon fiber reinforced plastics (CFRPs) are made from prepregs prepared by melt and mortar technologies, so the rheological properties of the polyimide binder were investigated. The heat resistance of carbon plastics was researched and its elastic-strength characteristics were determined at temperatures up to 320°С. The fundamental possibility of manufacturing carbon fiber from prepregs based on polyimide binder, obtained both by melt and mortar technologies, is shown. CFRPs made from two types of prepregs have a high glass transition temperature: 364°C (melt) and 367°C (solution), with this temperature remaining at the 97% level after boiling, and also at approximately the same (86–97%) level of conservation of elastic strength properties at temperature 300°С.


2021 ◽  
Vol 2 (2) ◽  
pp. 419-430
Author(s):  
Ankur Bajpai ◽  
James R. Davidson ◽  
Colin Robert

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.


Life ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 43
Author(s):  
Lamya Zahir ◽  
Takumitsu Kida ◽  
Ryo Tanaka ◽  
Yuushou Nakayama ◽  
Takeshi Shiono ◽  
...  

An innovative type of biodegradable thermoplastic elastomers with improved mechanical properties from very common and potentially renewable sources, poly(L-lactide)-b-poly(2-methyl-1,3-propylene glutarate)-b-poly(L-lactide) (PLA-b-PMPG-b-PLA)s, has been developed for the first time. PLA-b-PMPG-b-PLAs were synthesized by polycondensation of 2-methyl-1,3-propanediol and glutaric acid and successive ring-opening polymerization of L-lactide, where PMPG is an amorphous central block with low glass transition temperature and PLA is hard semicrystalline terminal blocks. The copolymers showed glass transition temperature at lower than −40 °C and melting temperature at 130–152 °C. The tensile tests of these copolymers were also performed to evaluate their mechanical properties. The degradation of the copolymers and PMPG by enzymes proteinase K and lipase PS were investigated. Microbial biodegradation in seawater was also performed at 27 °C. The triblock copolymers and PMPG homopolymer were found to show 9–15% biodegradation within 28 days, representing their relatively high biodegradability in seawater. The macromolecular structure of the triblock copolymers of PLA and PMPG can be controlled to tune their mechanical and biodegradation properties, demonstrating their potential use in various applications.


2018 ◽  
Vol 136 (12) ◽  
pp. 47230 ◽  
Author(s):  
Marlène Desloir ◽  
Cyril Benoit ◽  
Amine Bendaoud ◽  
Pierre Alcouffe ◽  
Christian Carrot

Author(s):  
Galina S. Bozhenkova ◽  
Alexandra N. Tarakanovskaya ◽  
Oksana D. Tarnovskaya ◽  
Roman V. Ashirov

The article is devoted to the production of polymer by metathesis ring-opening polymerization under the influence of ruthenium initiator of type of Hoveyda-Grubbs II generation. The monomer used the mixture of dimethyl ether norbornene-2;3-dicarboxylic acid. The monomer was prepared by the Diels-Alder reaction of dicyclopentadiene and dimethyl maleate. The polymer was prepared in bulk of the monomer mixture. In this paper we have studied the physical and mechanical properties polydimethyl ether of norbornene-2;3-dicarboxylic acid; and assessed the impact of environmental factors on the change in properties of the polymer. As environmental factors; light; UV radiation; water; 0.1 M hydrochloric acid were applied; and accelerated aging conditions; which were held in a climate chamber. During performance we found that maintaining the polymer samples in the UV light chamber led to the slight increase in flexural modulus. In contrast; the polymer storage in water and in a hydrochloric acid solution for two months resulted in a slight decrease in the modulus of elasticity in bending index. These factors did not affect the change in the glass transition temperature of the polymer. Under the conditions of accelerated aging conducted for 1; 2 and 6 days after two cycles we observed the drop in modulus for bending of 8.5%; after 6 cycles of 13%. The glass transition temperature of polydimethyl ether of norbornene-2;3-dicarboxylic acid after 6 cycles decreased by only 3.4% in the climatic chamber. Studies have shown that the resulting polymer is resistant to water; hydrochloric acid; light and UV radiation; as well as it saves properties at a sufficient level for operation at conditions of accelerated aging. It should be noted that the tested polymer was prepared without additives; stabilizers and antioxidants. The proposed polymer can be used as a structural material for machine parts; including bulky.For citation:Bozhenkova G.S.; Tarakanovskaya A.N.; Tarnovskaya O.D.; Ashirov R.V. Influence of environmental factors on physical-mechanical properties of polydimethyl ether of norborene -2;3-dicarboxylic acid. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 5. P. 68-73


2018 ◽  
Vol 16 (36) ◽  
pp. 153-171
Author(s):  
Nahida J. H.

The present work studies the mechanical properties of SiO2 μPs, and NPs in St/PVA blends. The samples were prepared by casting method as PVA, St/PVA blends at different concentrations (30, 40, 50, and 60 %). DSC and TGA tests were carried out to the samples evolved. The result showed a single glass transition temperature (Tg) for all St /PVA blends that was attributed to the good miscibility of the blends involved. It was found that (Tg) decrease with starch ratio increase. It was seen that (PVA) of (Tg=105 oC); The glass transition temperature which was decrease with starch ratio that was attributed to glass transition relaxation process due to micro-Brownian motion of the main chain back bond. The endothermic peak at 200 oC was attributed to melting point of (PVA). Thermal properties of PVA; and St /PVA blends at different concentration (30, 40, 50, and 60 %) were evaluated by thermo gravimetric analysis (TGA). The analyses were carried out from 20 to 600 oC at 10 oC)/min heating rate in air oxygen atmosphere. The weight loss stages depended on polymer system. The starch addition causing shifting in the second degradation temperature to the higher temperature; which result in overlapping between the two main degradation steps, these result was attributed to the St/ PVA blend compatibility. The mechanical properties results showed a decrease in ultimate strength with starch ratio increase. The ultimate strength of (PVA) was (47 MPa), whereas the ultimate strength of 60 %St/PVA was (11 MPa) and for 30 %St/PVA was the highest ultimate strength of blends involved (26 MPa). SiO2μPs (753.7 nm), and NPs (263.1 nm) were added at different concentrations (1.5, 2, and 2.5 %). 1.5% SiO2μPs, and NPs of the best ultimate strength (69 MPa), (86 MPa) respectively then it was decreased by SiO2μPs, and NPs increase. Optical microscope of the samples involved was investigated. It was concluded the prepared samples were suggested to be used as packaging materials for agriculture application and its ultimate strength could be controlled by SiO2μPs, and NPs addition.


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