Competition between cure and thermal degradation in a high Tg epoxy system: Effect of time and temperature of isothermal cure on the glass transition temperature

1990 ◽  
Vol 39 (4) ◽  
pp. 909-933 ◽  
Author(s):  
K. P. Pang ◽  
J. K. Gillham
2004 ◽  
Vol 205 (14) ◽  
pp. 1858-1862 ◽  
Author(s):  
Katrin Wondraczek ◽  
Jörg Adams ◽  
Jürgen Fuhrmann

2020 ◽  
Vol 11 (2) ◽  
pp. 393-400 ◽  
Author(s):  
Ke Cao ◽  
Joel M. Serrano ◽  
Tianyu Liu ◽  
Benjamin J. Stovall ◽  
Zhen Xu ◽  
...  

The glass transition temperature, thermal degradation temperature, and complex viscosity of metal sulfonated polyetherimides decrease with an increase in metal cation size.


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.


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.


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