Color change of poly(vinyl alcohol) during heat treatment (dehydration and formation of polyene fractions)

1967 ◽  
Vol 7 (1) ◽  
pp. 71-74 ◽  
Author(s):  
L. V. Smirnov ◽  
N. V. Platonova ◽  
K. R. Popov
Keyword(s):  
Heat Treatment ◽  
Vinyl Alcohol ◽  
Color Change ◽  
Poly Vinyl Alcohol

scholarly journals Morphological and Thermal Properties of Poly(Vinyl Alcohol)/Layered Double Hydroxide Hybrid Nanocomposite Fibers

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
A. F. Al Naim ◽  
J. Mazher ◽  
S. S. Ibrahim
Keyword(s):  
Crystal Structure ◽  
Heat Treatment ◽  
Layered Double Hydroxide ◽  
Vinyl Alcohol ◽  
Separation Distance ◽  
Molecular Vibration ◽  
Poly Vinyl Alcohol ◽  
Rapid Weight Loss ◽  
Different Temperatures ◽  
Double Hydroxide

Nanolayered particulate of Zn-based layered double hydroxide (LDH) was prepared by a low temperature greener sol-gel method. X-ray diffraction (XRD) studies were performed on the particles annealed at different temperatures. Hexagonal crystal structure of the as-grown LDH particulates was observed. The crystal structure was modified to tetragonal structure of layered double oxide (LDO) on annealing at 250°C. Rietveld fittings showed a collapse of interlayer separation distance along the preferred orientation of the LDH particles as a result of heat treatment. Further, LDH particles were used as fillers of electrospun poly(vinyl alcohol) (PVA) fibers. Heat treatment of the polymer fibers was also performed at different temperatures, and thermal changes were studied by thermogravimetric analysis (TGA), Raman spectroscopy, and scanning electron microscopy (SEM) techniques. Improved interaction of fibers with LDH nanoparticles was observed and ascribed to LDH-related LDO phase transformation at higher temperature. Thermal mechanisms of the rapid weight loss in filled fibers were discussed in comparison to the pure PVA fiber losses. Experimental Raman frequencies of the composite fibers were compared with the calculated Raman modes of the enol and ZnO monomers. The molecular vibration frequencies were found to differ significantly due to heat treatment. Finally, the role filler in the faster and greener thermal decomposition of polymeric fibers was also discussed in the present work.

scholarly journals Effect of Stereoregularity of Poly (Vinyl Alcohol) on the Crystallization by Heat-Treatment

1967 ◽  
Vol 24 (271) ◽  
pp. 746-750 ◽  
Author(s):  
Masamitsu Nagano ◽  
Masakazu Fujita ◽  
Hajime Nakatsuka
Keyword(s):  
Heat Treatment ◽  
Vinyl Alcohol ◽  
Poly Vinyl Alcohol

scholarly journals Effect of heat treatment on morphology and crystallinity of electrospun Poly(vinyl alcohol) nanofibers

2016 ◽  
Author(s):  
Tyas Ari Wahyu Wijanarko ◽  
Ahmad Kusumaatmaja ◽  
Chotimah ◽  
Roto ◽  
Kuwat Triyana
Keyword(s):  
Heat Treatment ◽  
Vinyl Alcohol ◽  
Poly Vinyl Alcohol

Characterization of Poly (Vinyl Alcohol) /Silver Nanocomposites Prepared by Heat Treatment Method

2010 ◽  
Vol 26-28 ◽  
pp. 127-130 ◽  
Author(s):  
Wei Pan ◽  
Hui Li ◽  
Yan Chen
Keyword(s):  
Heat Treatment ◽  
Vinyl Alcohol ◽  
Treatment Method ◽  
Poly Vinyl Alcohol ◽  
Scanning Calorimetry ◽  
Transmission Electron ◽  
Ag Particles ◽  
Nanoparticle Composites ◽  
Heat Treatment Method

Poly (vinyl alcohol) (PVA)/silver (Ag) nanoparticle composites were prepared via heat treatment of a mixture solution of silver nitrate (AgNO3) and PVA. The resultant composites were characterized by infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and differential scanning calorimetry (DSC). XRD results showed that pure phase Ag was obtained in the prepared nanocomposites. They also showed that crystallinity of PVA was largely decreased after the composition with nano-sized Ag. TEM results showed that the Ag particles were in sphere shape with 10-40nm diameter in the as-prepared nanocomposites. DSC results showed that the glass transition temperature of the nanocomposites was enhanced by the incorporation of Ag.

Preparation and characterization of α-chitin whisker-reinforced poly(vinyl alcohol) nanocomposite films with or without heat treatment

Polymer ◽  
2005 ◽  
Vol 46 (15) ◽  
pp. 5637-5644 ◽  
Author(s):  
Jittrawadee Sriupayo ◽  
Pitt Supaphol ◽  
John Blackwell ◽  
Ratana Rujiravanit
Keyword(s):  
Heat Treatment ◽  
Vinyl Alcohol ◽  
Nanocomposite Films ◽  
Poly Vinyl Alcohol
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