Polyvinyl alcohol as foaming agent in foam formed paper

TAPPI Journal ◽  
2019 ◽  
Vol 18 (8) ◽  
pp. 475-485
Author(s):  
JENS-MIKAEL GOTTBERG ◽  
TIMO LAPPALAINEN ◽  
KRISTIAN SALMINEN
Keyword(s):  
Polyvinyl Alcohol ◽  
Molar Mass ◽  
Sodium Dodecyl ◽  
Strength Properties ◽  
Water Soluble ◽  
Degree Of Hydrolysis ◽  
Hydroxyl Groups ◽  
Water Soluble Polymer ◽  
Foaming Agent ◽  
Air Content

The use of polyvinyl alcohol (PVOH or PVA) as a foaming agent in foam formed paper was investigated. Polyvinyl alcohol is a linear, nonionic water-soluble polymer. It has hydrophobic and hydrophilic parts that give it a surface-active character. PVOH is mainly characterized by degree of hydrolysis and molar mass. Degree of hydrolysis is given as mol-% hydroxyl groups on the polymer. Molar mass is measured indirectly by measuring the viscosity of a 4% PVOH solution. The results show that the degree of hydrolysis of PVOH had a strong effect on the foamability of PVOH. Foamability decreased strongly when the degree of hydrolysis increased from 88 to 98 mol-%. The effect of molar mass on foamability was weaker. We saw an increase in foam stability and bubble size with increasing molar mass, but we did not see any effect on maximum air content. PVOH dosage needed to reach >70% air content (Φ) varied from 2 g/l up to 10.5 g/l, and the lowest addition levels of PVOH needed were achieved with a low molar mass PVOH with a low degree of hydrolysis. The best strength properties were achieved when using fully hydrolyzed PVOH as the foaming agent. Strength properties (both in- and out-of-plane) of samples made using PVOH were better than those made using an anionic foaming agent (sodium dodecyl sulfate, SDS). By adding PVOH binder fibers to the pulp, we were able to further enhance the strength properties of paper and board.

scholarly journals The Influence of Surfactant (SDS) on the Adsorption Properties of Polyvinyl Alcohol and Polyethylene Glycol in an Alumina/Solution System

2002 ◽  
Vol 20 (6) ◽  
pp. 573-582 ◽  
Author(s):  
S. Chibowski ◽  
M. Paszkiewicz ◽  
M. Wiśniewska
Keyword(s):  
Polyethylene Glycol ◽  
Polyvinyl Alcohol ◽  
Adsorption Layer ◽  
Sodium Dodecyl ◽  
Adsorption Properties ◽  
Degree Of Hydrolysis ◽  
Ionic Polymers ◽  
Solution System ◽  
Molecular Weights ◽  
Polymer Surfactant

The influence of sodium dodecyl sulphate (SDS) on the adsorption properties of non-ionic polymers, i.e. polyethylene glycol (PEG) and polyvinyl alcohol (PVA), at the Al2O3/solution interface was studied. Measurements for various molecular weights and for various amounts of functional groups on the polymer macromolecules were undertaken and the results obtained discussed in the light of these variations. Studies of the mutual interactions of the polymer–surfactant system in aqueous solution were helpful in explaining the equilibria involved in the Al2O3/polymer solution system in the presence of SDS. The thickness of the adsorption layer was determined by viscometric methods and the influence of the degree of hydrolysis of PVA on the structure of the adsorption layer demonstrated.

The Development and the Study of the Properties of Hydrosorption Material Based on a Blended Thermoplastic Vulcanisate

2017 ◽  
Vol 44 (8) ◽  
pp. 9-14
Author(s):  
M.F. Galikhanov ◽  
D.M. Akhmedzyanova ◽  
N.R. Nikitin
Keyword(s):  
Diffusion Processes ◽  
Testing Machine ◽  
Strength Properties ◽  
Water Soluble ◽  
Butadiene Rubber ◽  
Tensile Testing Machine ◽  
Water Soluble Polymer ◽  
Electret State ◽  
Swelling Rate ◽  
Negative Effect

Hydrosorption thermoplastic vulcanisates (TPVs) with a controllable swelling rate have been developed. They contain low-density polyethylene (LDPE), nitrile butadiene rubber (NBR), and sodium carboxymethyl cellulose (Na-CMC) – a water-soluble polymer (WSP). They were mixed on a laboratory mill in two stages and vulcanised at a temperature of 170°C. At the first stage, the NBR with a vulcanising system and carbon black were mixed with the WSP at 50°C, and at the second stage this composite was mixed with the polyethylene (PE) at 140°C. The hydrosorption, deformation and strength, and electret properties of the obtained TPVs were studied. The study of the sorption properties under conditions of limited and unlimited access of water showed that composites consisting of 25% polyethylene and 75% WSP swell in water by ∼28%, and here processes of migration of the WSP out of the composites are absent. The deformation and strength properties were determined on an Inspekt Mini TR-3 kN tensile testing machine. The level of deformation and strength characteristics of the obtained TPVs is not high, which is due to the low adhesion between the PE and the polar NBR, and also between the NBR and the WSP. However, for seals and gaskets, the achievable level of strength properties is quite adequate. An electret state of the TPVs was obtained in a negative corona discharge as they cooled down after heating to 90°C. Washers were manufactured from the developed TPVs, and they were tested for their sealing capacity. It was shown that the electret state inhibits the process of swelling of the TPVs in water, which is due to the negative effect of the electric field on the rate at which wetting, dissolution, and diffusion processes take place. However, during service, the electret state of articles manufactured from the developed TPVs rapidly relaxes, after which the swelling process occurs at a steady rate. This makes it possible to carry out assembly work involving the fitting or replacement of seals made of the hydrosorption TPVs.

scholarly journals Study on the Preparation and Lipophilic Properties of Polyvinyl Alcohol (PVA) Nanofiber Membranes via Green Electrospinning

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2514
Author(s):  
Jun Cong Ge ◽  
Guirong Wu ◽  
Sam Ki Yoon ◽  
Min Soo Kim ◽  
Nag Jung Choi
Keyword(s):  
Polyvinyl Alcohol ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Environmentally Friendly ◽  
Contact Angles ◽  
Water Soluble ◽  
Engine Oil ◽  
Bet Surface Area ◽  
Water Soluble Polymer ◽  
Nanofiber Membranes

As an environmentally friendly water-soluble polymer, polyvinyl alcohol (PVA) has attracted extensive attention because of its non-toxic, degradable, low cost, and good biocompatibility. Electrospinning is a kind of nanotechnology, and the nanofiber membrane prepared by it has the advantages of large surface area-to-volume ratios, nano- to micron-sized fibers, etc. Herein, a simple and facile one-step green electrospinning method was developed to fabricate various environmentally friendly PVA nanofiber membranes. The lipophilic properties of PVA membranes were investigated and optimized according different PVA concentrations. The PVA electrospun fiber prepared from the solution at a concentration of 10 wt% had the highest adsorption capacity for the adsorption of new and waste engine oils, and the waste engine oil adsorption capacity (12.70 g/g) was higher than that of new engine oil (11.67 g/g). It also has a relatively large BET surface area (12.05 m2/g), a pore volume (0.04 cm3/g), and an appropriate pore diameter (13.69 nm) and fiber diameter (174.21 nm). All electrospun PVA membranes showed excellent lipophilic properties due to their oil contact angles of much less than 30°. Therefore, PVA electrospun fibrous membranes have great application potential in the field of purifying engine oil due to the excellent lipophilic properties and oil absorption capacity.

scholarly journals A novel esterase DacApva from Comamonas sp. strain NyZ500 with deacetylation activity for acetylated polymer polyvinyl alcohol

2021 ◽  
Author(s):  
Chao-Fan Yin ◽  
Ying Xu ◽  
Shi-Kai Deng ◽  
Wen-Long Yue ◽  
Ning-Yi Zhou
Keyword(s):  
Polyvinyl Alcohol ◽  
High Energy ◽  
Water Soluble ◽  
Backbone Cleavage ◽  
Water Soluble Polymer ◽  
Prevotella Ruminicola ◽  
Rich Media ◽  
Acetyl Group ◽  
High Pollution ◽  
Novel Esterase

As a water-soluble polymer, the widely used polyvinyl alcohol (PVA) is produced from hydrolysis of polyvinyl acetate. Microbial PVA carbon backbone cleavage via a two-step reaction of dehydrogenation and hydrolysis has been well studied. Content of acetyl group is a pivotal factor affecting performance of PVA derivatives in industrial application, and deacetylation is a non-negligible part in PVA degradation. However, the genetic and biochemical studies of its deacetylation remain largely elusive. Here, Comamonas sp. strain NyZ500 was isolated for its capability of growing on acetylated PVA from activated sludge. A spontaneous PVA-utilization deficient mutant strain NyZ501 was obtained when strain NyZ500 was cultured in rich media. Comparative analysis between the genomes of these two strains revealed a fragment (containing a putative hydrolase gene dacApva) deletion in NyZ501 and dacApva-complemented strain NyZ501 restored the ability to grow on PVA. DacApva, which shares 21% identity with xylan esterase AxeA1 from Prevotella ruminicola 23, is a unique deacetylase catalyzing the conversion of acetylated PVA and its derivatives to deacetylated counterparts. This indicates that strain NyZ500 utilizes acetylated PVA via acetate as a carbon source to grow. DacApva also possessed the deacetylation ability for acetylated xylan and the antibiotic intermediate 7-aminocephalosporanic acid (7ACA) but the enzymes for the above two compounds had no activities against PVA derivatives. This study enhanced our understanding of the diversity of microbial degradation of PVA and DacApva characterized here is also a potential biocatalyst for the eco-friendly biotransformation of PVA derivatives and other acetylated compounds. IMPORTANCE: Water-soluble PVA, which possesses a very robust ability to accumulate in the environment, has a very grave environmental impact due to its widespread use in industrial and household applications. On the other hand, chemical transformation of PVA derivatives is currently being carried out at high energy consumption and high pollution conditions using hazardous chemicals (such as NaOH, methanol) under high temperatures. The DacApva reported here performs PVA deacetylation under mild conditions, then it has a great potential to be developed into an eco-friendly biocatalyst for biotransformation of PVA derivatives. DacApva also has deacetylation activity for compounds other than PVA derivatives, which facilitates its development into a broad-spectrum deacetylation biocatalyst for production of certain desired compounds.

scholarly journals Preparation and Pharmaco-Mechanical Characterization of Ketoprofen- Polyvinyl Alcohol Cryogel for Medical Applications

2019 ◽  
Vol 70 (3) ◽  
pp. 848-852
Author(s):  
Monica Iliuta Stamate ◽  
Lacramioara Ochiuz ◽  
Daniel Timofte ◽  
Bogdan Ciuntu ◽  
Cristina Ghiciuc ◽  
...  
Keyword(s):  
Polyvinyl Alcohol ◽  
Mechanical Characterization ◽  
Water Soluble ◽  
Mechanical Resistance ◽  
Medical Applications ◽  
Water Soluble Polymer ◽  
Different Temperatures ◽  
Polymeric Solutions ◽  
Equilibrium Swelling Ratio

Polyvinyl alcohol is a biocompatible polymer used very commonly both in pharmaceutical and medical fields. Being a water-soluble polymer, it is suitable for the manufacture of hydrogels as well as cryogels used for various medical applications. The present work describes the preparation, structural and physico-mechanical characterization of polyvinyl alcohol cryogels loaded with ketoprofen. By cryogenic technique the polymeric solutions are transformed under certain conditions into porous, elastic and very compressible structures. They are able to absorb a large amount of liquids that they give off by gentle compression. The prepared cryogels were evaluated for different physical, chemical and structural properties, as following: internal morphology, equilibrium swelling ratio and mechanical testing. The cryogel structures show good elasticity and optimal swelling at different temperatures. Due to these properties the studied cryogels are suitable for use in various medical applications involving liquid absorption, mechanical resistance and anti-inflammatory effect.

scholarly journals Preparation of PVA Fluorescent Gel and Luminescence of Europium Sensitized by Terbium (III)

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 893
Author(s):  
Yifan Wei ◽  
Zhengquan Fu ◽  
Hao Zhao ◽  
Ruiqi Liang ◽  
Chengyu Wang ◽  
...  
Keyword(s):  
Rare Earth ◽  
Film Formation ◽  
Electronic Configuration ◽  
Rare Earth Ions ◽  
Water Soluble ◽  
Fluorescence Properties ◽  
Hydroxyl Groups ◽  
Water Soluble Polymer ◽  
Quenching Effect ◽  
Wide Range

Polyvinyl alcohol (PVA) gel has a very wide range of applications in agriculture, military, industry, and other fields. As a widely used water-soluble polymer, PVA has good mechanical properties, excellent spinnability, good hydrophilicity, remarkable physical and chemical stability, good film formation, is non-polluting, and exhibits good natural degradation and biocompatibility. It is an ideal gel preparation material. Incorporation of rare-earth elements into PVA polymers can be used to prepare rare-earth luminescent gel materials. Results show that the luminescent efficiency of complexes is mainly related to their structure, ligand substituents, synergists, and the electronic configuration of doped rare-earth ions. Fluorescent gel films were prepared by adding europium, terbium, and europium/terbium co-doped into PVA, and their fluorescence properties were compared and analyzed. It was found that, in addition to the above factors, the sensitization of terbium to europium, and the fluorescence-quenching effect of hydroxyl groups, will influence the fluorescence properties. This has opened a new route for the application of rare-earth materials and may have value in the field of new materials.

scholarly journals Effect of Polyvinyl Alcohol on the Rheological Properties of Cement Mortar

Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 754
Author(s):  
Fang Liu ◽  
Baomin Wang ◽  
Yunqing Xing ◽  
Kunkun Zhang ◽  
Wei Jiang
Keyword(s):  
Polyvinyl Alcohol ◽  
Rheological Properties ◽  
Yield Stress ◽  
Cement Mortar ◽  
Chemical Properties ◽  
Degree Of Polymerization ◽  
Plastic Viscosity ◽  
Water Soluble ◽  
Water Soluble Polymer ◽  
Hydrolysis Degree

Polyvinyl alcohol (PVA) is a kind of water-soluble polymer, which has been widely used in different industries due to its excellent mechanical and chemical properties. In this paper, the effects of polyvinyl alcohol with different hydrolysis and polymerization degrees on the rheological properties of cement mortar are studied. The results show that the rheological properties of PVA-modified cement mortar can be described by the modified Bingham model. The yield stress of modified cement mortar is less than that of unmodified mortar when the degree of polymerization and the content of PVA are small. With the increase of polyvinyl alcohol content and polymerization degree, the yield stress and plastic viscosity of modified cement mortar increase sharply, which are larger than those of the unmodified cement mortar. However, the effect of hydrolysis degree of PVA on yield stress and plastic viscosity of modified cement mortar is not obvious.

scholarly journals Electrospun synthesis of silver/poly (vinyl alcohol) nano-fibers: investigation antibacterial activity and flame retardant property

2021 ◽  
Author(s):  
Sara Azarakhsh ◽  
Hamed Bahiraei ◽  
Gholamhosain Haidari ◽  
Davood Ghanbar
Keyword(s):  
Polyvinyl Alcohol ◽  
Flame Retardant ◽  
Ag Nanoparticles ◽  
Average Particle Size ◽  
Water Soluble ◽  
Poly Vinyl Alcohol ◽  
Average Particle ◽  
Sem Images ◽  
Water Soluble Polymer ◽  
Nano Fiber

Abstract Polyvinyl alcohol (PVA) and Ag nanoparticles-embedded polyvinyl alcohol (Ag/PVA) nano-fibers have been synthesized successfully via the electro-spinning technique at room temperature. XRD patterns confirmed the presence of Ag nanoparticles in the electro-spinning PVA nano-fibers. FE-SEM images displayed that silver nanoparticles with an average particle size of 32 nm are uniformly dispersed in PVA nano-fibers. Also, the average diameter of Ag/PVA nano-fibers was estimated to be 142 nm. The EDX analysis of Ag/PVA nano-fiber determined the aggregation of Ag nanoparticles in the range of polymer nano-fibers. The antibacterial property of Ag/PVA nano-fiber for inhibition of Escherichia coli (E-coli) growth was approved. Since polyvinyl alcohol is a biocompatible and water-soluble polymer, it can be considered as unique candidate for the preparation of wound dressing nano-fibers. It is also found that the nontoxic nanostructures can appropriately enhance both flame retardant and thermal stability properties of the Ag/PVA matrix. These results show that the Ag/PVA nano-fibers may find practical applications as self-reinforced medical devices and tissue-engineering scaffolds.

scholarly journals Studying the Effectiveness of Polyacrylamide (PAM) Application in Hydrocarbon Reservoirs at Different Operational Conditions

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2201 ◽  
Author(s):  
Kingsley Godwin Uranta ◽  
Sina Rezaei-Gomari ◽  
Paul Russell ◽  
Faik Hamad
Keyword(s):  
Oil Recovery ◽  
Pure Water ◽  
Attenuated Total Reflection ◽  
Water Soluble ◽  
Solution Viscosity ◽  
Resonance Spectroscopy ◽  
Degree Of Hydrolysis ◽  
Water Soluble Polymer ◽  
Operational Conditions ◽  
Hydrocarbon Reservoir

The water-soluble polymer PAM (polyacrylamide) is used in enhanced oil recovery (EOR) operations. It is pumped into water injection wells to increase the viscosity of the injected water and in turn to direct more oil towards production wells. This EOR process is proven to be sensitive to operational well conditions such as hydrocarbon reservoir temperature, as well as the salinity of the injected water and/or formation water. These operational conditions lead to technical challenges ranging from the solubility of PAM in injection water to the behaviour of PAM inside the reservoir. To gain a clear picture of the functionality of PAM in EOR applications, this report characterizes its behaviour of in terms of degree of hydrolysis and changes in solution viscosity determined using Perkin Elmer spectrum 100 Fourier transform infrared-Attenuated total reflection (FTIR)-ATR and nuclear magnetic resonance spectroscopy (1H NMR) and a Fann model 35 Couette and Cole Parmer rotational viscometer, respectively. Different shear rates were investigated to determine the effect of shear on PAM gel stability. Experiments were performed for PAM mixed with formation brine at 50, 70, and 90 °C for ageing times of up to 30 days. The results indicate that the degree of hydrolysis achieved after 30 days is much higher in saline solutions than in pure water, and that this effect is more pronounced at higher temperatures. For example, after 30 days at 50 °C, the hydrolysis level was observed to be 53%, rising to 65% at 70 °C and 75% at 90 °C in PAM mixed with brines. Similar trends were observed with viscosity, where lower viscosity was observed for samples at higher temperatures and salinities. It is thus reasonable to conclude that the degree of hydrolysis causes changes in the viscosity of the polymer gel, leading to a decline in its performance as it ages.

Preparation and properties of melamine formaldehyde resin modified by functionalized nano-SiO2 and polyvinyl alcohol

2020 ◽  
pp. 096739112090354
Author(s):  
Zhu Xiong ◽  
Ning Chen ◽  
Qi Wang
Keyword(s):  
Thermal Stability ◽  
Impact Strength ◽  
Polyvinyl Alcohol ◽  
Flame Retardant ◽  
Flame Retardancy ◽  
Water Soluble ◽  
Hot Water ◽  
Formaldehyde Resin ◽  
Melamine Formaldehyde ◽  
Water Soluble Polymer

Melamine formaldehyde (MF) resin is a thermosetting polymer with superior flame retardancy and high thermal stability and is widely used in fire-retardant coatings, flame-retardant sheets, heat-resistant filter materials, and so on. However, its further application is restricted by its extreme brittleness and poor impact strength. In this article, polyvinyl alcohol (PVA), a water-soluble polymer with high toughness and elasticity, which can be well blended with MF prepolymer in hot water, was used to improve the toughness of MF resin. The nano-silicon dioxide (SiO2) particles modified by KH-550 were used to improve the compatibility between MF prepolymer and PVA. Moreover, the modified nano-SiO2 can simultaneously enhance the toughness and impact the strength of MF resin. The interaction of components, fractography, thermal stability, flame retardancy, and mechanical properties of the modified MF resin was studied systematically. Fourier transform infrared results indicate that KH-550 was successfully grafted onto the surface of nano-SiO2. The grafted nano-SiO2 shows better dispersion in the matrix than the unmodified one, furthermore improving the compatibility and interface adhesion between MF and PVA. When PVA content is 20%, the obtained material has good thermal stability ( T max > 350°C), flame-retardant properties (UL-94 V-0 rating and limited oxygen index = 42%), and toughness (elongation at break > 20% and unnotched impact strength > 13 kJ m−2).

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