Crystallization Behavior of Polyvinyl Alcohol with 1,2-Diol Side-Chains

2018 ◽  
Vol 33 (2) ◽  
pp. 234-244 ◽  
Author(s):  
M. Shibutani ◽  
T. Yamamoto ◽  
K. Inoue ◽  
K. Tokumitsu
2016 ◽  
Vol 49 (16) ◽  
pp. 5963-5977 ◽  
Author(s):  
Sotiria Kripotou ◽  
Christina Psylla ◽  
Konstantinos Kyriakos ◽  
Konstantinos N. Raftopoulos ◽  
Junpeng Zhao ◽  
...  

2021 ◽  
Author(s):  
Ruru Huang ◽  
Yane Zhang ◽  
Aimin Xiang ◽  
Songbai Ma ◽  
huafeng tian ◽  
...  

Abstract Polyvinyl alcohol (PVA) decompose before melting, making it difficult for melt processing. This phenomenon limits the applications of PVA. Therefore, to widen the application of PVA, in the present work, the PVA films have been prepared by the flow casting method. And talc added as an inorganic nucleating agent to improve the crystallinity of PVA. The effects of talc on the crystallization behavior of PVA are tested by differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and successive self-nucleation annealing (SSA). The crystallization kinetics behavior of talc was is further studied by Mo Zhishen equation and Avrami equation. The results show that the addition of talc to the PVA film promotes its crystallization, and as the content of the nucleating agent increases, the crystallinity tends to increase, and the thickness of the wafer becomes uniform due to the increase of nucleation points. These results show that talc regulates the crystallization of PVA, improves the crystallinity and crystallization rate of PVA, and has a heterogeneous nucleation effect. PVA itself exhibits hydrophilicity because it contains large number of hydroxyl groups, and has good physical and chemical properties. In addition, the mechanical properties and water resistance have been further improved by improving the crystallinity of PVA, and the practicability of PVA film in actual production was improved.


Author(s):  
T.R. Dinger ◽  
G. Thomas

The use of Si3N4, alloys for high temperature, high stress structural applications has prompted numerous studies of the oxynitride glasses which exist as intergranular phases in their microstructures. Oxynitride glasses have been investigated recently in their bulk form in order to understand their crystallization behavior for subsequent Si3N4 applications and to investigate their worth as glass-ceramic precursors. This research investigates the crystallization sequence of a glass having a normalized composition of Y26Si30Al11 ON11 and lying in the A1N-Y2O3-SiO2 section of the Y-Si-Al-O-N system. Such glasses exist as intergranular phases in the technologically important Y2O3/Al2O3-fluxed Si3N4 alloys.


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