A review on microphase separation measurement techniques for polyurethanes

Gholami, Mahdi; Haddadi‐Asl, Vahid; Jouibari, Iman Sahebi

doi:10.1177/87560879221088939

Cited by 24 publications

(17 citation statements)

References 141 publications

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“…Due to the influential role of phase separation on PU properties, a myriad of approaches including Fourier‐transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), scanning electron and transmission electron microscopy (SEM and TEM), small angle x‐ray scattering (SAXS), and so forth have been employed to study the microphase separation of PUs 35,36 …”

Section: Polyurethanesmentioning

confidence: 99%

“…34 Due to the influential role of phase separation on PU properties, a myriad of approaches including Fouriertransform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), scanning electron and transmission electron microscopy (SEM and TEM), small angle x-ray scattering (SAXS), and so forth have been employed to study the microphase separation of PUs. 35,36 As a synthetic polymer, the most significant feature of PU is adjustability. PUs can be fabricated with different hard and soft segments and processing parameters to represent versatile properties and to be appropriate for various applications.…”

Section: Polyurethanesmentioning

confidence: 99%

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A review on electrically conductive polyurethane nanocomposites: From principle to application

Jafarzadeh,

Farzaneh,

Haddadi‐Asl

et al. 2023

Polymer Composites

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Polyurethanes (PUs) thanks to the occurrence of phase separation and biphasic structure prevail over other polymer matrixes for impregnation of conductive fillers and production of conductive composites. A number of carbonous fillers including carbon black, carbon fiber, carbon nanotube, graphite and its derivatives, and fullerene can be loaded into the PU matrixes to impart electrical conductivity. The properties of the carbonous fillers, the filler/PU interactions, and the method of compositing determine the conductive performance of the composite. It is possible to modulate the properties of the conductive PU composites and employ them for a number of electronic applications including but not limited to the strain sensors, electromagnetic interference shielding materials, supercapacitors, and tissue engineering scaffolds. In the present review, first, the distinctive properties of PU as a matrix of conductive composites have been discussed. Then, various carbon fillers loaded into the PU matrixes and their structural and conductive properties have been debated. Thereafter, the fabrication methods of the conductive composites as well as the influential parameters on the electrical properties of the composites have been reviewed to provide an insight into how fulfill a PU composite with the desired electrical performance. And finally, a number of applications of conductive PU composites have been put forward.Highlights Polyurethanes are very capable matrixes for conductive composites. Carbonous fillers can be loaded into the PU matrixes to impart conductivity. Conductive PU composites are employed for a number of electronic applications. Herein, properties, fillers, and applications of PU composites are reviewed.

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Section: Polyurethanesmentioning

confidence: 99%

Section: Polyurethanesmentioning

confidence: 99%

A review on electrically conductive polyurethane nanocomposites: From principle to application

Jafarzadeh,

Farzaneh,

Haddadi‐Asl

et al. 2023

Polymer Composites

Self Cite

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“…When rigid segments segregate from the flexible segment, the final PU increases its degree of crystallinity. However, the crystallinity also depends on other factors, such as the symmetry or the nature of both the diisocyanate and the chain extender, as well as the preparation procedure [ 4 , 12 , 14 , 15 , 16 , 17 ]. The melting point of the final PU is also affected by the composition of the rigid segment; in particular, the melting temperature increases with the content of the rigid segment.…”

Section: Introductionmentioning

confidence: 99%

The Role of Diisocyanate Structure to Modify Properties of Segmented Polyurethanes

Asensio

Ferrer

Nohales³

et al. 2023

Materials

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Segmented thermoplastic polyurethanes (PU) were synthetized using a polycarbonatediol macrodiol as a flexible or soft segment with a molar mass of 2000 g/mol, and different diisocyanate molecules and 1,4-butanediol as a rigid or hard segment. The diisocyanate molecules employed are 3,3′-Dimethyl-4,4′-biphenyl diisocyanate (TODI), 4,4′-diphenylmethane diisocyanate (MDI), 4,4’-Methylenebis(phenyl isocyanate) 1-isocyanato-4- [(4-phenylisocyanate)methyl]benzene and 1-isocyanate-4-[(2-phenylisocyanate) methyl]benzene (ratio 1:1) (MDIi), isophorone diisocyanate (IPDI), and hexamethylene diisocyanate (HDI). The polyurethanes obtained reveal a wide variation of microphase separation degree that is correlated with mechanical properties. Different techniques, such as DSC, DMA, and FTIR, have been used to determine flexible–rigid segment phase behavior. Mechanical properties, such as tensile properties, Shore D hardness, and “compression set”, have been determined. This work reveals that the structure of the hard segment is crucial to determine the degree of phase miscibility which affects the resulting mechanical properties, such as tensile properties, hardness, and “compression set”.

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“…In contrast, the weaker hydrogen bonding between urethane-ether or urethane-ester groups gives rise to phase mixing. 10 Thus, the proportion of hydrogen bonds formed between the HS (NH…O C) might be used as a measure of the extent of phase separation. The fraction of hydrogen bonds between the hard and SS (NH…O) represents the extent of phase mixing between hard and soft segments.…”

Section: Introductionmentioning

confidence: 99%

“…The strongest hydrogen bonding between urethane–urethane groups is responsible for the microphase separation. In contrast, the weaker hydrogen bonding between urethane–ether or urethane–ester groups gives rise to phase mixing 10 . Thus, the proportion of hydrogen bonds formed between the HS (NH…OC) might be used as a measure of the extent of phase separation.…”

Section: Introductionmentioning

confidence: 99%

Waterborne polyurethane dispersions based on polypropylene glycol/polycarbonate diol: Evaluation of their use as wood protective coatings

Alves,

Pacheli Heitmann,

Ayres

et al. 2023

J of Applied Polymer Sci

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When exposed to the open air, the wood can change its physical and structural properties due to the combined effect of ultraviolet radiation, oxygen, humidity, atmospheric pollutants, and microorganisms. The demand for durable coatings with application to wooden structures or pieces is always a relevant topic. Waterborne polyurethane (WPU) dispersions as wood protective coatings might be attractive, especially outdoors. In this work, WPU dispersions have been synthesized from isophorone diisocyanate and different ratios of polypropylene glycol and polycarbonate (PC) diol. Synthesized polyurethanes were applied to wood surfaces as a coating. The results showed that the partial and total replacement of polypropylene glycol (PPG) by PC influences the mechanical, thermal, and structural properties of the films obtained from aqueous polyurethane dispersions. In addition, a simple and promising methodology based on Fourier‐transform infrared (FTIR) spectra was proposed to determine the polycarbonate content in poly(carbonate‐ether‐urethane). The synthesized coatings reduced water absorption by the wood, especially the one with a 25:75 polycarbonate to PPG ratio. The applied coating does not impact the final color of the wood, allowing a natural aging effect. Polyurethanes are promising for use as coatings for wood.

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A review on microphase separation measurement techniques for polyurethanes

Cited by 24 publications

References 141 publications

A review on electrically conductive polyurethane nanocomposites: From principle to application

A review on electrically conductive polyurethane nanocomposites: From principle to application

The Role of Diisocyanate Structure to Modify Properties of Segmented Polyurethanes

Waterborne polyurethane dispersions based on polypropylene glycol/polycarbonate diol: Evaluation of their use as wood protective coatings

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