New Hydrogen Bonding Enhanced Polyvinyl Alcohol Based Self‐Charged Medical Mask with Superior Charge Retention and Moisture Resistance Performances

2021 ◽  
pp. 2009172
Author(s):  
Nannan Wang ◽  
Yange Feng ◽  
Youbin Zheng ◽  
Liqiang Zhang ◽  
Min Feng ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Polyvinyl Alcohol ◽  
Moisture Resistance ◽  
Charge Retention

Natural weather ageing of starch/polyvinyl alcohol blend: effect of glycerol content

2013 ◽  
Vol 33 (3) ◽  
pp. 257-263 ◽  
Author(s):  
Sreekumar Parambathmadhom Appu ◽  
Sadhan Kumar De ◽  
Massihullah J. Khan ◽  
Mamdouh A. Al-Harthi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Hydrogen Bonding ◽  
Polyvinyl Alcohol ◽  
Weather Conditions ◽  
Intermolecular Hydrogen Bonding ◽  
Biodegradable Material ◽  
Glycerol Content ◽  
Fourier Transfer Infrared Spectroscopy ◽  
Scanning Electron

Abstract Starch plasticized with glycerol and blended with polyvinyl alcohol (PVA) is recommended for use as a biodegradable material. The present article reports the results of studies of the natural weather ageing of starch/PVA blends having various amounts of glycerol in natural weather conditions of Saudi Arabia, with special reference to morphology and thermal behavior. Neat PVA has been used as a control to understand its behavior in its blend with starch. Differential scanning calorimeter studies indicated that an increase in the exposure time of samples to natural environment increases the crystallinity of PVA due to the breakage of intermolecular hydrogen bonding, thus facilitating the removal of the amorphous portion of the polymers in the blend. Thermogravimetric analysis revealed that an increase in glycerol content enhanced the degradation of the polymer, which is corroborated with the findings from the surface morphology using scanning electron microscopy and Fourier transfer infrared spectroscopy analyses.

Effect of Gamma Irradiation on the Microstructure and Morphology of Polyethylene Oxide and Polyvinyl Alcohol Blends

2009 ◽  
Vol 83-86 ◽  
pp. 524-529
Author(s):  
Mariam Al-Ma'adeed ◽  
N.J. Al-Thani
Keyword(s):  
Thin Films ◽  
Thermal Stability ◽  
Hydrogen Bonding ◽  
Free Radicals ◽  
Polyvinyl Alcohol ◽  
Polyethylene Oxide ◽  
Diffusion Controlled ◽  
High Doses ◽  
Higher Doses ◽  
Very High

Thin films of a blend of 90, 75, 50 (wt/wt%) percentage of polyethylene oxide and polyvinyl alcohol were synthesized and irradiated with 5, 25, 50, 100 and 200 kGy. The presence of PVA leads to diffusion controlled mechanism where it decreases the crystallinity of PEO as restricted crystallization occurs.Low doses of 5 kGy cause crosslinking of the blends and increase the thermal stability. Higher doses up to 100 kGy cause the PEO crystallite boundaries to be erased and to blur spherulites structure; it also leads to an increase in the crystallinity. Higher doses of 200 kGy cause an increase in the hydrogen bonding where the material is more crystalline in structure and broken down which made more segments available for the hydrogen bonding. Degradation and oxidation of the blends due to the presence of free radicals in the polymer irradiated in air is noticed for blends with very high doses. Never the less, PVA in these blends protects the PEO composite from the effect of radiation.

The use of polarized infra-red radiation in the study of doubly oriented long-chain polymers

1949 ◽  
Vol 199 (1057) ◽  
pp. 183-198 ◽  
Keyword(s):  
Hydrogen Bonding ◽  
Polyvinyl Alcohol ◽  
Strong Support ◽  
Nylon 66 ◽  
Polyvinylidene Chloride ◽  
Infra Red ◽  
Valency Angle ◽  
Red Radiation ◽  
Long Chain ◽  
High Polymers

The use of polarized infra-red radiation in examining the structure and orientation of high polymers has been investigated quantitatively. It is shown that infra-red spectroscopy can furnish evidence for double orientation in rolled sheets of nylon 66, polyvinyl alcohol and (with less certainty) polythene. In the case of polyvinyl formate, acetate, chloride and polyvinylidene chloride such double orientation could not be detected. Evidence is given to show that in nylon the N -H bond is bent by hydrogen bonding forces, the angle between this bond and the plane of the skeleton being thereby reduced from 39° (the valency angle) to 22°. The structure of polyvinyl alcohol recently proposed by Bunn receives strong support from the absence of dichroism in the O-H frequency in the spectrum of that material, when a doubly oriented specimen is examined.

scholarly journals Tensile Strength and Moisture Resistance Properties of Biocomposite Films Based on Polyvinyl Alcohol (PVA) with Cellulose as Reinforcement from Durian Peel Fibers

2021 ◽  
Vol 302 ◽  
pp. 02001
Author(s):  
Melbi Mahardika ◽  
Mochamad Asrofi ◽  
Devita Amelia ◽  
Edi Syafri ◽  
Sanjay Mavinkere Rangappa ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Polyvinyl Alcohol ◽  
Cellulose Fibers ◽  
Moisture Resistance ◽  
Solution Casting ◽  
Casting Method ◽  
Elongation At Break ◽  
Biocomposite Films ◽  
Solution Casting Method ◽  
Biocomposite Film

Polyvinyl Alcohol (PVA) based biocomposite film with cellulose was successfully fabricated by the solution casting method. The cellulose fibers were obtained by extraction of durian peel using alkalization and bleaching treatments. These treated cellulose fibers were used for the fabrication of PVA-based biocomposites. The durian peel cellulose fibers were varied by 2%, 4%, 6%, and 8% in the PVA matrix. Tensile test and moisture resistance of biocomposites were evaluated. The 6% addition of cellulose fibers in biocomposites increases the tensile strength up to 54% (37 MPa) than pure PVA film (24 MPa). Conversely, it reduces the elongation at break of the biocomposite film. Meanwhile, the moisture resistance properties of the biocomposites increased with the addition of cellulose fibers. The tensile strength and moisture resistance of biocomposites have been increased due to the homogeneous dispersion of the cellulose fibers and PVA matrix. These biocomposites able to reduce the environmental impacts by utilizing residual lignocellulosic biomass.

Remarkable enhancement of ambient-air electrical conductivity of the perylenediimide π-stacks isolated in the flexible films of a hydrogen-bonded polymer

RSC Advances ◽  
2015 ◽  
Vol 5 (79) ◽  
pp. 64240-64246 ◽  
Author(s):  
Mustafa Supur ◽  
Ayhan Yurtsever ◽  
Ümit Akbey
Keyword(s):  
Electrical Conductivity ◽  
Hydrogen Bonding ◽  
Polyvinyl Alcohol ◽  
Aqueous Solutions ◽  
Ambient Air ◽  
Π Interactions ◽  
Flexible Films ◽  
Hydrogen Bonded

N,N′-di(2-(trimethylammoniumiodide)ethylene) perylenediimide (TAIPDI), forming extensive π-stacks through the strong π–π interactions of large π-planes, was isolated in the hydrogen-bonding milieu of polyvinyl alcohol (PVA) from aqueous solutions.

scholarly journals Simple Vanilla Derivatives for Long-Lived Room-Temperature Polymer Phosphorescence as Invisible Security Inks

Research ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Yongfeng Zhang ◽  
Zhonghao Wang ◽  
Yan Su ◽  
Yan Zheng ◽  
Wenji Tang ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Polyvinyl Alcohol ◽  
Room Temperature ◽  
Reading Strategy ◽  
Ambient Conditions ◽  
Data Encoding ◽  
Emission Time ◽  
Phosphorescence Emission ◽  
Multiple Cycles ◽  
Application Scope

Developing novel long-lived room-temperature polymer phosphorescence (RTPP) materials could significantly expand their application scope. Herein, a series of RTPP materials based on eight simple vanilla derivatives for security ink application are reported. Attributed to strong mutual hydrogen bonding with polyvinyl alcohol (PVA) matrix, vanilla-doped PVA films exhibit ultralong phosphorescence emission under ambient conditions observed by naked eyes, where methyl vanillate shows the longest emission time up to 7 s. Impressively, when vanilla-doped PVA materials are utilized as invisible security inks, and the inks not only present excellent luminescent emission stability under ambient conditions but also maintain perfect reversibility between room temperature and 65°C for multiple cycles. Owing to the unique RTPP performance, an advanced anticounterfeiting data encoding/reading strategy based on handwriting technology and complex pattern steganography is developed.

Hydrogen bonding in liquid methanol at ambient conditions and at high pressure

2000 ◽  
Vol 98 (3) ◽  
pp. 125-134 ◽  
Author(s):  
T. Weitkamp, J. Neuefeind, H. E. Fisch
Keyword(s):  
High Pressure ◽  
Hydrogen Bonding ◽  
Ambient Conditions
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