scholarly journals Syntheses of Colorless and Transparent Polyimide Membranes for Microfiltration

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1610
Author(s):  
Jong Won Kim ◽  
Jin-Hae Chang
Keyword(s):  
Heat Treatment ◽  
Composite Material ◽  
Composite Films ◽  
Porous Membrane ◽  
Amic Acid ◽  
Water Soluble ◽  
Poly Vinyl Alcohol ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
Water Soluble Polymer

Herein, poly(amic acid) (PAA) was synthesized using 4,4’-(hexafluoroisopropylidene) diphthalic anhydride (6FDA) as a dianhydride and 2,2-bis(3-aminophenyl)hexafluoropropane (6FAm) and 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (6FAm-OH) as diamines. Poly(vinyl alcohol) (PVA) at various contents (0–5.0 wt%) was blended with PAA to prepare a composite material. Then, colorless and transparent polyimide (CPI) composite films were prepared by applying various stages of heat treatment using the PAA/PVA blend film as a precursor. These film-type composites were immersed in water to completely dissolve PVA, a water-soluble polymer, and their pore sizes were investigated to determine their potential as a porous membrane. According to the results of scanning electronic microscopy (SEM), as the concentration of PVA increased from 0 to 5.0 wt% in the CPI/PVA composite films, the size of the pores resulting from the dissolution of water-soluble PVA increased. Further, the micrometer-sized pores were uniformly dispersed in the CPI films. The thermal properties, morphology, and optical transparency of the two types of CPI membranes synthesized using 6FAm and 6FAm-OH monomers were examined and compared.

scholarly journals Colorless and Transparent Polyimide Microporous Film with Excellent Physicochemical Property

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1298
Author(s):  
Jong Won Kim ◽  
Seon Ju Lee ◽  
Moon Young Choi ◽  
Jin-Hae Chang
Keyword(s):  
Pore Size ◽  
Porous Membrane ◽  
Amic Acid ◽  
Water Soluble ◽  
Poly Vinyl Alcohol ◽  
Thermal Stabilities ◽  
Blend Films ◽  
Hydrogen Bonding Interactions ◽  
Heat Treated ◽  
Microporous Film

4,4′-(4,4′-isopropylidenediphenoxy)bis(phthalic anhydride) (BPADA) as a dianhydride and bis(3-aminophenyl) sulfone (APS) and bis(3-amino-4-hydroxyphenyl) sulfone (APS-OH) as diamines were used to synthesize two types of poly(amic acid) (PAA). Varying amounts (0–5.0 wt%) of water-soluble poly(vinyl alcohol) (PVA) were mixed with PAA, and the resulting blend was heat-treated at different stages to obtain the colorless and transparent polyimide (CPI) blend films. The synthesized blended film completely removed water-soluble PVA in water. The possibility as a porous membrane according to the pore size varied according to the amount of PVA was investigated. The dispersibility and compatibility of CPI containing APS-OH monomer were higher than those of the APS monomer. This could be attributed to the hydrogen-bonding interactions between the CPI main chains and PVA. Scanning electron microscopy was conducted to characterize the material. The results revealed that the pore size of the CPI blend film increased as the PVA concentration increased. It was confirmed that uniform pores of μm-size were observed in CPI. The thermal stabilities, morphologies, optical properties, and solubilities of two CPIs obtained using APS and APS-OH monomers were investigated and their properties were compared with each other.

scholarly journals Self-Healing Polymer-Clay Hybrids by Facile Complexation of a Waterborne Polymer with a Clay

2021 ◽  
Author(s):  
Aranee Pleng Teepakakorn ◽  
Makoto Ogawa
Keyword(s):  
Vinyl Alcohol ◽  
Aqueous Media ◽  
Water Soluble ◽  
Poly Vinyl Alcohol ◽  
Self Healing ◽  
Soluble Polymer ◽  
Water Soluble Polymer ◽  
Smectite Clay

Water-induced self-healing materials were prepared by the hybridization of a water-soluble polymer, poly(vinyl alcohol), with a smectite clay by mixing in an aqueous media and subsequent casting. Without using chemical...

scholarly journals Fabrication of novel porous membrane from biobased water-soluble polymer (hydroxypropylcellulose)

2017 ◽  
Vol 526 ◽  
pp. 212-220 ◽  
Author(s):  
A. Hanafia ◽  
C. Faur ◽  
A. Deratani ◽  
P. Guenoun ◽  
H. Garate ◽  
...  
Keyword(s):  
Porous Membrane ◽  
Water Soluble ◽  
Soluble Polymer ◽  
Water Soluble Polymer

scholarly journals Preparation and Assessment of Heat-Treated α-Chitin Nanowhiskers Reinforced Poly(viny alcohol) Film for Packaging Application

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1883 ◽  
Author(s):  
Chao Peng ◽  
Guangxue Chen
Keyword(s):  
Heat Treatment ◽  
Composite Films ◽  
Barrier Properties ◽  
Mechanical Tests ◽  
Light Transmittance ◽  
Poly Vinyl Alcohol ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heat Treated ◽  
Chitin Nanowhiskers

In this study, poly(vinyl alcohol) (PVA) composite films enhanced by α-chitin nanowhiskers (ChWs) were prepared through heat treatment. The obtained membranes were assessed by means of FTIR spectroscopy, X-ray diffraction, thermogravimetric analysis, regular light transmittance, mechanical tests, permeability and water absorption. The influence of the nano-component and heat treatment on the mechanical, thermal and water-resistant properties of the composite membrane were analyzed. From the results of the work, the produced films with excellent barrier properties and inexpensive raw processed materials have great prospects in packaging applications.

Rheological properties of pectin, poly(vinyl alcohol) and their blends in aqueous solutions

e-Polymers ◽  
2012 ◽  
Vol 12 (1) ◽  
Author(s):  
Katarzyna Lewandowska ◽  
Aldona Dąbrowska ◽  
Halina Kaczmarek
Keyword(s):  
Aqueous Solutions ◽  
Rheological Properties ◽  
Vinyl Alcohol ◽  
Water Soluble ◽  
Poly Vinyl Alcohol ◽  
Concentric Cylinder ◽  
Water Soluble Polymer ◽  
Flow Measurements ◽  
Result Show ◽  
Different Temperatures

AbstractThe new blends composed of natural polysaccharide - pectin and synthetic water soluble polymer - poly(vinyl alcohol) (PVA) are attractive materials due to their biocompatibility, non-toxicity and biodegradability. In this work the rheological properties of aqueous solutions of pectin (PEC), poly(vinyl alcohol) and their mixtures at various weight ratios (70/30, 50/50, 30/70) have been investigated. Flow measurements were carried out using a rotary viscometer with concentric cylinder at different temperatures (20-70 ºC) and shear rates (24- 1234 s-1). The flow parameters and energy of activation have been calculated from the flow curves and Arrhenius plots, respectively. It was found that studied polymer solutions exhibited non-Newtonian behavior, moreover, the flow properties were dependent on the blend composition. The result show that practically there was no thixotropy in studied system but some interactions between PVA and pectin in water occurred.

Rendering Rayon Fibres Antimicrobial and Thermal-Responsive via Layer-by-Layer Self-Assembly of Functional Polymers

2011 ◽  
Vol 236-238 ◽  
pp. 1103-1106 ◽  
Author(s):  
Yuan Feng Pan ◽  
Hui Ning Xiao
Keyword(s):  
Self Assembly ◽  
Guanidine Hydrochloride ◽  
Antimicrobial Property ◽  
Water Soluble ◽  
Solution Temperature ◽  
Poly Vinyl Alcohol ◽  
Layer By Layer ◽  
Anionic Polymer ◽  
Water Soluble Polymer ◽  
Lbl Assembly

A thermal-responsive polymer was prepared by partially acetalyzing poly(vinyl alcohol) (PVA). The completely reversible polymer aggregation and dissolution occur above and below a low critical solution temperature (LCST) for the aqueous solution of the modified PVA. The partially acetalized PVA (APVA) with higher molecular weight and higher degree of acetalysis exhibited a lower LCST transition and was used as an anionic polymer for polymer complexation. Water-soluble polymer, cationic polyhexamethylene guanidine hydrochloride (CPHGH) with antimicrobial property, was also prepared. In conjunction with APVA, CPHGH created the unique antimicrobial polymer multilayers on the surfaces of rayon fibres via layer by layer (LbL) assembly. AFM images revealed that the particles generated by multilayers became larger after the material was treated at 60°C; while the roughness of the surfaces was increased as the layer number increased and then decreased. Moreover, antimicrobial tests also demonstrated that the rayon fiber assembled with (CPHGH/APVA) multilayers exhibited higher antimicrobial activity against E. coli and s. aureus.

Poly(Vinyl Alcohol) (Core)-Polyurethane (Shell) Nanofibers Produced by Coaxial Electrospinning

2016 ◽  
Vol 705 ◽  
pp. 68-71 ◽  
Author(s):  
Ga Young Park ◽  
So Young Lee ◽  
Woo Jin Kim ◽  
Jin Hyun Choi
Keyword(s):  
Vinyl Alcohol ◽  
Water Soluble ◽  
Polymer Mixture ◽  
Poly Vinyl Alcohol ◽  
Coaxial Electrospinning ◽  
Resonance Spectroscopy ◽  
Bioactive Substances ◽  
Water Contact ◽  
Water Soluble Polymer ◽  
Small Pore

Nanoweb fabricated by electrospinning has a large specific area and a small pore size which can be controlled through a spinning process to enable a strong adsorption and selective permeability. It is required to produce nanofiber of different polymer mixture with a limited miscibility for improvement of physical, chemical, or biological properties. In this study, poly (vinyl alcohol) (PVA)/polyurethane (PU) nanofibers were produced by coaxial electrospinning. PVA (core)/PU (shell) nanofibers were defect-free and had a uniform thickness. The pseudo core/shell structure of PVA/PU nanofibers was confirmed by transmission electron microscopy. The presence of PVA and PU in the nanofibers was identified by 13C solid state nuclear magnetic resonance spectroscopy, fourier transform infrared spectroscopy, and X-ray diffraction analysis. Water contact angle was reduced by incorporation of PVA in a core of PU nanofiber. For variety of biomedical applications, bioactive substances such as antibiotics and proteins can be incorporated in a core of hydrophobic PU nanofiber by coaxial electrospinning of water-soluble polymer/bioactive substance mixture.

Design and Construction of Porous Structures in PVDF Membranes in Phase Separation Processes

2011 ◽  
Vol 335-336 ◽  
pp. 895-898
Author(s):  
Guo Lan Huan ◽  
Jian Li Liu ◽  
Qi Yun Du ◽  
Xiao Yu Hu
Keyword(s):  
Phase Separation ◽  
Porous Membrane ◽  
Water Soluble ◽  
Microporous Membranes ◽  
Porous Structures ◽  
Separation Processes ◽  
Water Soluble Polymer ◽  
Membrane Morphology ◽  
The Relationship ◽  
System Water

In this article, the morphologies of membranes formed by three different systems, i.e. favorable diluent/unfavorable diluent/PVDF system, water-soluble solvent/ unfavorable diluent/PVDF system, and favorable diluent/unfavorable diluent/water-soluble polymer/PVDF system, were characterized, and the relationship between porous membrane morphology and the components of favorable diluent/unfavorable diluent and water-soluble solvent/unfavorable diluent in the system was investigated. The transformation from mesopores to bicontinuous porous structures, from finger-shaped pores to bicontinuous porous structures was realized, and meanwhile PVDF microporous membranes with microfiber-shaped porous structures were manufactured.

Macro-Defect-Free Cement: A Novel Organoceramic Composite

1992 ◽  
Vol 271 ◽  
Author(s):  
J. Francis Young ◽  
M. Berg
Keyword(s):  
Composite Material ◽  
Chemical Interaction ◽  
Water Soluble ◽  
High Shear ◽  
Soluble Polymer ◽  
Water Soluble Polymer ◽  
Hydraulic Cement

ABSTRACTMacro-defect-free cement is a composite material made by processing a hydraulic cement with a water-soluble polymer under high shear roll-milling. This paper examines the principles of processing and the development of microstructure that results in a material with ceramic-like properties. The nature of the chemical interaction between the cement and the polymer is also considered in some detail.

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