scholarly journals Micelle-template synthesis of hollow silica spheres for improving water vapor permeability of waterborne polyurethane membrane

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Yan Bao ◽  
Tong Wang ◽  
Qiaoling Kang ◽  
Chunhua Shi ◽  
Jianzhong Ma
Keyword(s):  
Water Vapor ◽  
Template Synthesis ◽  
Water Vapor Permeability ◽  
Waterborne Polyurethane ◽  
Vapor Permeability ◽  
Silica Spheres ◽  
Hollow Silica ◽  
Hollow Silica Spheres ◽  
Polyurethane Membrane

Effect of hollow silica spheres on water vapor permeability of polyacrylate film

RSC Advances ◽  
2015 ◽  
Vol 5 (15) ◽  
pp. 11485-11493 ◽  
Author(s):  
Yan Bao ◽  
Chunhua Shi ◽  
Yongqiang Yang ◽  
Jianzhong Ma ◽  
Risong Sha
Keyword(s):  
Electron Microscopy ◽  
Shell Thickness ◽  
Water Vapor Permeability ◽  
Vapor Permeability ◽  
Silica Spheres ◽  
X Ray Diffraction ◽  
Hollow Silica ◽  
X Ray ◽  
Hollow Silica Spheres ◽  
Transmission Electron

Hollow silica spheres with different hollow size and shell thickness were synthesized via a template method using PS spheres as templates and characterized by transmission electron microscopy, scanning electron microscopy, X-ray diffraction and Brunauer–Emmett–Teller analysis.

Polyurethane Electrospun Fiber Biomimetics Membrane for Constructing the Structure of Grain Layer with Good Breathability for Cattle Split Leather

2021 ◽  
Vol 116 (8) ◽  
Author(s):  
Nan Chen ◽  
Yanchun Li ◽  
Jianbo Qu ◽  
Jian-Yong Wang
Keyword(s):  
Water Vapor ◽  
Electrospun Fiber ◽  
Water Vapor Permeability ◽  
Waterborne Polyurethane ◽  
Vapor Permeability ◽  
High Porosity ◽  
Foam Layer ◽  
Fiber Morphology ◽  
Woven Structure ◽  
Superfine Fiber

The traditional thick coating on split leather does not have the ability to breathe like full grain leather.  The air and water vapor permeabilities of full grain leather are well known properties due to its fiber woven structure. Simulating the fiber morphology and weaving structure of the dermis or grain layer is very important to construct a top surface layer for split leather. In this paper, a PU (polyurethane) foam layer is put first on the split to enhance the adhesion of a second application of a superfine fibrous PU resin. This foam uses well-known waterborne polyurethane foaming technology. This dried foam has good breathability because of high porosity. A superfine fiber membrane is next put atop of the foam layer by using an electro-spun polyurethane resin. This second resin imitates collagen fibers in the network structure of the leathers’ grain layer. Thus, this resultant electrospun fiber biomimetics membrane simulated the grain layer of natural leather. SEM showed the morphology and structure of this electrospun fiber biomimetic membrane to be like that of the grain layer of natural leather. The porosity and apparent density were basically the same as the grain of leather, which were 63.65% and 583.878 kg/m3 respectively. The air and water vapor permeability of the biomimetics membrane were also as high as 2250 mL·cm-2·h-1 and 8753.02 μg·cm-2·h-1 respectively. Therefore, the biomimetics membrane largely restored the ability to breathe of split leather. Thus, this method simulates the performance and structure of full grain leather and is a novel method for industrial production

Influence of Low Temperature Plasma on Chitosan/ Waterborne Polyurethane Finishing on Cotton Fabric

2014 ◽  
Vol 1051 ◽  
pp. 117-120
Author(s):  
Wei Ling Wang ◽  
Wei Dong Yu
Keyword(s):  
Water Vapor ◽  
Volume Ratio ◽  
Water Vapor Permeability ◽  
Waterborne Polyurethane ◽  
Vapor Permeability ◽  
Temperature Plasma ◽  
Aqueous Emulsion ◽  
Recovery Performance ◽  
Pre Treatment ◽  
Property Changes

Waterborne polyurethane and chitosan were mixed in different volume ratio, and finished on the cotton of plasma pre-treatment and non-plasma pre-treatment to discuss the influence of plasma pretreatment on the properties of the fabric. Firstly, the mixed aqueous emulsion was made into film and analyzed by FTIR. Secondly, the relationship between the properties of whiteness, wrinkle recovery performance and water vapor permeability of the fabric that finished by the only blended solution and the mixed ratio was studied. Finally, the property changes between the pretreatment with and without plasma was compared. The results showed that, the blended film not only had both polyurethane and chitosan characteristic peaks, but also generated the new characteristic peaks; the three properties of the fabric that finished by the only blended solution changed with the mixed ratio; the plasma pre-treatment would increase the fabric’s whiteness, decrease wrinkle recovery performance, but the water vapor permeability would improve obviously.

Elucidating the Relationship Between Structure and Property of Waterborne Polyurethane-Cellulose Nanocrystals Nanocomposite Films

2020 ◽  
Vol 12 (8) ◽  
pp. 1213-1224
Author(s):  
Ya-Yu Li ◽  
Wei-Wen Jing ◽  
Jian-Hua Wang ◽  
Jun-Fang Li
Keyword(s):  
Water Vapor ◽  
Cellulose Nanocrystals ◽  
Food Packaging ◽  
Mechanical Performance ◽  
Water Vapor Permeability ◽  
Waterborne Polyurethane ◽  
Optical Transmittance ◽  
Nanocomposite Films ◽  
Vapor Permeability ◽  
Casting Technique

Cellulose nanocrystals (CNCs) are promising polymer reinforcements owning to their biocompatibility and high elastic modulus, low density, nano size, and inherent biocompatibility. The waterborne polyurethane-cellulose nanocrystals (WPU-CNCs) nanocomposite films were prepared using the conventional solvent casting technique over a whole composition. The mechanical performance, optical transmittance, amphiphilicity, water vapor permeability (WVP), and oxygen permeability (OP) of these WPU-CNCs films were evaluated. The incorporation of CNCs into WPU resulted in a significant enhancement of Young's modulus and tensile strength. The WVP of nanocomposite films had a lowest value at CNCs content of 50 wt.%. Upon the increase of CNCs content from 0 to 90 wt.%, the transmission path of oxygen molecular through the nanocomposite films became more tortuous, leading to drastic decrease in the OP. These WPU-CNCs nanocomposite films with high strength, optical transparency, water vapor and oxygen barrier properties have the potential applications in biomedical, furniture coating, and food packaging fields.

Ultraviolet blocking and antioxidant polyvinyl alcohol films incorporated with baicalin extraction from Scutellaria baicalensis Georgi

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jinshu Liu ◽  
Xiaoyan Ma ◽  
Wenzhao Shi ◽  
Jianwei Xing ◽  
Chaoqun Ma ◽  
...  
Keyword(s):  
Water Vapor ◽  
Polyvinyl Alcohol ◽  
Radical Scavenging Activity ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Water Vapor Permeability ◽  
Scutellaria Baicalensis ◽  
Vapor Permeability ◽  
Protective Film ◽  
Uv Blocking

Abstract Baicalin, an active flavonoid ingredient of Scutellaria baicalensis Georgi, was extracted by heat reflux extraction and showed the same significance UV absorption property with standard baicalin. Active films were prepared from polyvinyl alcohol (PVA) containing baicalin extract by casting method. The effect of baicalin extracts on the UV-blocking, optical, antioxidant property, water vapor permeability, swelling and mechanical properties of the films were studied. UV–vis transmittance spectra showed that PVA films incorporated with baicalin extract blocked ultraviolet light range from 280–400 nm even with low concentration of baicalin (0.5 wt%) and maintain the high transparency in visible spectrum. The outstanding UV-blocking properties of PVA films incorporated with baicalin extract were also confirmed by Rhodamine B degradation. Baicalin conferred antioxidant properties to PVA films as determined by DPPH radical scavenging activity. Due to the interaction between hydroxy groups of baicalin and PVA molecule, water vapor permeability, swelling and elongation at break of the films were decreased accompanied with the increasing in tensile strength and Young’s modulus. FTIR reveal that the interaction between PVA molecules was significant changed by the introduction of baicalin. These results suggest that PVA film incorporated with baicalin extract can be used for the development of functional protective film.

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