Synthesis, characterization and properties of waterborne polyurethanes based on two different ionic centers

Honarkar, Hengameh; Barmar, Mohammad; Barikani, Mehdi

doi:10.1007/s12221-015-0718-1

Cited by 30 publications

(17 citation statements)

References 22 publications

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“…The basic principle behind the stabilization mechanism of dispersions is the electrical double layer formation . As explained earlier, in dispersions, the hydrophilic polyurethane chains agglomerate as particles having a hydrophobic core and a hydrophilic boundary layer.…”

Section: Resultsmentioning

confidence: 98%

“…The layer of counter ions which is organized around this boundary layer of ionic charges, create an electrical double layer. The Coulombic repulsion between these colloidal particles is responsible for the dispersion stability . An increase in the DMPA/polyol molar ratio results in an increase in the number of ionic groups in the boundary layer of polyurethane particles.…”

Section: Resultsmentioning

confidence: 99%

“…The average particle size of polyurethane dispersions decreases with the increase of amount of dimethylolpropionic acid. This inverse correlation has been attributed to the stabilization mechanism of dispersed particles, which involves the diffusing electrical double layer formation . The increase in the solid content also leads to a decrease in particle size .…”

Section: Introductionmentioning

confidence: 99%

“…The presence of the pendent ionic groups in the polymer chain increases the ionic character in the molecule and increases the stability of the polyurethane dispersion in water. In addition, the introduction of ionic pedant groups to the polymer has been found to affect the physical properties of the films produced from the dispersions due to the formation of intermolecular Coulombic forces between ionic centers …”

Section: Introductionmentioning

confidence: 99%

“…While surface coatings that contain large particles have short drying times, coatings with small particles produce better penetration properties . The weight percentage of ionomer can also be used to control the particle size of aqueous polyurethane dispersions . The average particle size of polyurethane dispersions decreases with the increase of amount of dimethylolpropionic acid.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

The effect of change of ionomer/polyol molar ratio on dispersion stability and crystalline structure of films produced from hydrophilic polyurethanes

Senevirathna

Amarasinghe

Karunaratne

et al. 2016

J of Applied Polymer Sci

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In this study, we report the effect of the DMPA/PTHF molar ratio on dispersion properties of the MDI-based hydrophilic polyurethane dispersions. In addition, the effect of the DMPA/PTHF molar ratio on the crystallinity and thermal properties of the polyurethane films prepared from dispersions are also discussed. The variation in stability was studied using a particle size analyzer. DSC and XRD analyses were used to study variations in crystallinity of films with the change of DMPA/PTHF molar ratio. FT-IR spectra were used to monitor the formation of hydrogen bonds through urethane linkages to produce hard-segment crystalline areas. The zeta potential increased with the increase of DMPA/PTHF molar ratio (hard-segment content), while particle size of polyurethane particles decreased. Hence, the stability of dispersions was increased with DMPA/PTHF molar ratio due to the increase of hydrophilicity in polymer chain. Crystallinity of the films was increased with DMPA/PTHF molar ratio due to the increase of interchain interactions through Coulombic interactions and hydrogen bonding. Consequently, crystalline melting temperature was increased with the increase of DMPA/PTHF molar ratio. However, molten films formed crystalline soft segments instead of crystalline hard segments during slow cooling.

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Section: Resultsmentioning

confidence: 98%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

The effect of change of ionomer/polyol molar ratio on dispersion stability and crystalline structure of films produced from hydrophilic polyurethanes

Senevirathna

Amarasinghe

Karunaratne

et al. 2016

J of Applied Polymer Sci

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Functional Zwitterionic Polyurethanes as Gate Dielectrics for Organic Field‐Effect Transistors

Sun,

Hu,

Chen

et al. 2024

Adv Elect Materials

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The development of polymeric dielectrics with a high dielectric constant is of great significance for flexible low‐voltage organic field‐effect transistors (OFETs). Herein, functional polyurethanes (PUs) with nitro and sulfobetaine zwitterionic groups are synthesized, and their electrical properties, mechanical properties, and the performances of OFET devices using these zwitterionic PUs as gate dielectrics are studied. Compared with sulfobetaine zwitterion‐containing PUs, nitro‐containing PUs (NO2‐PUs) show higher dielectric constant up to 6.5. Both zwitterionic PUs enhance the OFET performances, while the effect of NO2‐PU is more significant. Devices using NO2‐PU‐15 that contains 15 moL% nitro groups as the dielectric layer show the best performance and a threshold voltage (Vth) of as low as −0.02 V together with two orders’ increase of the mobility is observed, compared with the devices using PU without nitro groups. This study provides a new method to improve the dielectric constant of polymeric dielectrics, which is valuable for flexible/stretchable and wearable electronic devices.

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Practical two‐step chain extension method to prepare sulfonated waterborne polyurethanes based on aliphatic diamine sulphonate

Mou¹,

Wang²,

Yu³

et al. 2020

J of Applied Polymer Sci

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We reported a novel synthesis route to fabricate sulfonated aliphatic waterborne polyurethane dispersions (SWPU) only based on 2‐[(2‐aminoethyl) amino] ethane sulphonate sodium (AAS‐Na) by two‐step chain extension method with the assistance of acetone and water cosolvent. When AAS‐Na was added, only less than 50% of AAS‐Na was incorporated into polyurethane chain in the first‐step chain extension and the residual AAS‐Na formed molecular aggregates which were insoluble in acetone due to the high polarity of AAS‐Na. Subsequently, the mixture of acetone and water was added, the residual AAS‐Na aggregates dissolved, undertaking the further second‐step chain extension reaction, and the ultimate reaction conversion of AAS‐Na rose to more than 90%. The mechanism for acetone and water cosolvent to affect the preparation of SWPU dispersions was studied, as well as the water resistance, mechanical properties and hydrolysis resistance of as‐prepared SWPU dispersions. With the decrease of AAS‐Na content from 2.0% to 1.2%, the peak area of the melting peaks for SWPU films increased, as well as the water resistance. And the as‐prepared polyester SWPU exhibited good hydrolytic stability.

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Synthesis, characterization and properties of waterborne polyurethanes based on two different ionic centers

Cited by 30 publications

References 22 publications

The effect of change of ionomer/polyol molar ratio on dispersion stability and crystalline structure of films produced from hydrophilic polyurethanes

The effect of change of ionomer/polyol molar ratio on dispersion stability and crystalline structure of films produced from hydrophilic polyurethanes

Functional Zwitterionic Polyurethanes as Gate Dielectrics for Organic Field‐Effect Transistors

Practical two‐step chain extension method to prepare sulfonated waterborne polyurethanes based on aliphatic diamine sulphonate

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