Comparison of hydrogen bonding in polydimethylsiloxane and polyether based urethane and urea copolymers

Yılgör, Emel; Burgaz, Engin; Yurtsever, E.

doi:10.1016/s0032-3861(99)00245-1

Cited by 237 publications

(206 citation statements)

References 13 publications

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“…Single chain and double chain urea-based anionic surfactants (-alanine derivatives) [14] and anionic gemini surfactants derived from cysteine [15] showed better tendency to adsorb at the air/water interface than to form micelles. Urea-based gemini surfactants with octyl chains displayed cmc values comparable to other carboxylate surfactants of higher hydrocarbon chain length (decyl and dodecyl chains) [15] which is attributed to the hydrogen bonding ability of urea group [16]. Increase of micelle ionization degree and decrease in anion selectivity of cetyltrimethylammonium bromide and cetyltrimethylammonium chloride micelles in presence of urea indicates a preferential headgroup solvation by urea squeezing the counterions out of the Stern layer [17].…”

Section: Introductionmentioning

confidence: 82%

Urea-based gemini surfactants: Synthesis, aggregation behaviour and biological activity

Pisárčik

Pupák

Devı́nsky

et al. 2016

Colloids and Surfaces A: Physicochemical and Engineering Aspect

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Section: Introductionmentioning

confidence: 82%

Urea-based gemini surfactants: Synthesis, aggregation behaviour and biological activity

Pisárčik

Pupák

Devı́nsky

et al. 2016

Colloids and Surfaces A: Physicochemical and Engineering Aspect

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“…Dther peak at 1075 cm -1 is attributed to the stretching of C−D−C groups. The peak at 2269 cm -1 corresponding to the N=C=D residual groups and it only appears for CAPU, indicating that the reaction is not still complete or that the proportions are not for TPU) are attributed to the C=D free and H-bond (C=D) urethane respectively 11,30 and that at 3345 cm -1 N-H group stretch.…”

Section: Infrared Spectroscopymentioning

confidence: 99%

“…The PAni incorporation increases the T g from 3 °C to 18 °C for CAPU/SPAN 2.0 membranes and from 3 °C to 25 °C for the CAPU/PAni TSA membranes. The increase on T g due to the PAni incorporation can be explained considering the formation of H-bonds 30,32 between PAni amine groups and PU urethane groups as shown in Figure 6. The difference between CAPU/SPAN 2.0 and CAPU/PAni TSA temperatures can be explained by the stronger steric effect in the SPAN 2.0 than in the PAni TSA due to sulphonic group linked chemically to the aromatic ring, which would disfavor the formation of the H-bonds.…”

Section: Thermal Analysismentioning

confidence: 99%

Castor oil and commercial thermoplastic polyurethane membranes modified with polyaniline: a comparative study

et al. 2013

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The study of conducting polymeric membranes is decisive in some areas, as in fuel cells and electrodialysis. This work aims the study of membranes using conventional and conductive polymers blends. Two types of polyurethane were used as conventional polymers, commercial thermoplastic polyurethane and polyurethane synthesized from castor oil and 4-4-dicyclohexylmethane isocyanate. Two kinds of conducting polymers were used, polyaniline doped with organic acid and a self doped polyaniline. The polymers and the membranes were characterized by electrical conductivity, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA) and scanning electron microscopy (SEM). The synthesis of the membranes produced was proper, featuring a complete reaction, analyzed by FTIR. The membranes also showed good mechanical properties and thermal stability (≈ 220 °C). Among the membranes studied, the polyaniline doped with p-toluenesulphonic acid obtained higher thermal and viscoelastic properties. Thus they can be used in separation techniques using membranes.

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“…Besides a crystalline or at least highly ordered phase, soft and hard segments form corresponding phases which are partially soluble in each other [16][17][18][19][20][21]. Solubility depends very much on the interaction of the components, the urethane groups are capable of forming specific interactions, H-bonds with each other, but also with the soft segments [22,23]. Depending on preparation conditions, the final structure of the product is determined by kinetic effects, but a very large extent by interactions [24].…”

Section: Introductionmentioning

confidence: 99%

Specific interactions, structure and properties in segmented polyurethane elastomers

Bagdi

Molnár

Sajó

et al. 2011

Express Polym. Lett.

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Abstract. Two sets of segmented polyurethane (PU) elastomers were prepared from 4,4!-methylenebis(phenyl isocyanate) (MDI), 1,4-butanediol (BD) and a polyester or a polyether polyol, respectively. The molecular mass of both polyols was 1000 g/mol. The stoichiometric ratio of isocyanate and hydroxyl groups was 1 and the polyol/total diol ratio changed from 0 to 1 in 0.1 steps. One step bulk polymerization was carried out in an internal mixer and the samples were compression molded for testing. The results proved that specific interactions determine the phase structure and properties of these materials. Crystallinity was approximately the same in the two types of polyurethanes and the amount of relaxing soft segments was also similar. The determination of interaction parameters from solvent absorption and differences in glass transition temperatures indicated stronger interaction between hard and soft segments in the polyester than in the polyether polyurethane. Larger transparency of the polyester PU indicated the formation of smaller dispersed particles of the hard phase. The larger number of smaller hard phase units led to the formation of more physical cross-links distributed more evenly in the polymer. These differences in the phase structure of the polymers resulted in stronger strain hardening tendency, larger strength and smaller deformations for the polyester than for the polyether polyurethane.

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Comparison of hydrogen bonding in polydimethylsiloxane and polyether based urethane and urea copolymers

Cited by 237 publications

References 13 publications

Urea-based gemini surfactants: Synthesis, aggregation behaviour and biological activity

Urea-based gemini surfactants: Synthesis, aggregation behaviour and biological activity

Castor oil and commercial thermoplastic polyurethane membranes modified with polyaniline: a comparative study

Specific interactions, structure and properties in segmented polyurethane elastomers

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