Effect of soft/hard segments in poly (tetramethylene glycol)-Polyurethane for water barrier film

Kang, Kitaek; Jee, Chanhyuk; Bae, Ji‐Hong; Jung, Hun Young; Kim, Byeong Joo; Huh, PilHo

doi:10.1016/j.porgcoat.2018.04.014

Cited by 28 publications

(10 citation statements)

References 10 publications

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“…Regarding the T g , the PUR developed in this work has a much lower glass-rubber transition temperature than other polyurethane developed elsewhere for applications as transducer encapsulation (T g at around 0°C) [8] and also as water barrier film (T g in the range of -40°C). [9] www.advancedsciencenews.com www.ms-journal.de A lower glass-rubber transition temperature is necessary because these types of equipment (transducers) may be submitted to dynamic mechanical loading at lower temperatures, which could lead to a glass-rubber transition even at higher temperatures than regular T g obtained by DSC.…”

Section: Resultsmentioning

confidence: 99%

“…[4,6,8] An increase in mechanical properties, together with a restriction for water diffusion, can also be achieved by the incorporation of a chain extender in the PUR formulation. Kang et al (2018) and Schwerz et al (2016) showed that the use of short-chain diol to increase crosslink density, hard segment content and mechanical properties, also enhances the barrier to water transmission. [9,10] Therefore, it is known by the scientific community that the addition of fillers and chain extenders favor the barriers for water diffusion.…”

Section: Introductionmentioning

confidence: 99%

“…Kang et al (2018) and Schwerz et al (2016) showed that the use of short-chain diol to increase crosslink density, hard segment content and mechanical properties, also enhances the barrier to water transmission. [9,10] Therefore, it is known by the scientific community that the addition of fillers and chain extenders favor the barriers for water diffusion. Despite that, a comprehensive study to understand the influence of each ingredient on the mechanical, thermal, electric, and acoustic properties of PUR elastomers used for the encapsulation of hydroacoustic transducers is not yet addressed by the literature.…”

Section: Introductionmentioning

confidence: 99%

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Evaluation of Polyurethane Elastomers for Encapsulation of Hydroacoustic Transducers

Lemos

Lima

Cunha

et al. 2020

Macromolecular Symposia

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Hydroacoustic transducers are devices capable of converting mechanical energy from acoustic waves into electrical energy, and vice versa, through piezoelectric elements connected to electronics that need to be protected from contact with the water. This tightness is provided by the encapsulation of the transducers with elastomers. The use of fillers and chain extenders are known to promote a barrier for water diffusion, but it would inevitably change the other properties of the elastomer. Thus, this work aims to evaluate the effects of filler and chain extender addition on the properties of polyurethane elastomers (PUR) for this application. Thermogravimetric, thermomechanical, glass‐rubber transition temperature, hardness, and dielectric loss analyses are performed. It is observed an increase in the dielectric loss, hardness, and thermal stability with the addition of mineral fillers and carbon black. The addition of chain extender promoted a greater hardness in the final elastomer, but has no measurable effects on the dielectric loss, and decreased the thermal and dimension stability with temperature. Glass‐rubber transition temperatures remain in the range from –78 to –80 °C, which is in the acceptable range for the application as encapsulants.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Evaluation of Polyurethane Elastomers for Encapsulation of Hydroacoustic Transducers

Lemos

Lima

Cunha

et al. 2020

Macromolecular Symposia

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“…The tensile strength (32.0 MPa) of PTMG 2k -HMDI 2.5 was higher than those of all the reported PTMG-based TPUs, and PTMG 2k -HMDI 2.5 possessed a high elongation at break above 1300% simultaneously (Figure c). ,,,,,− This demonstrates that the robust and stretchable PTMG-based TPU can be prepared by selecting HMDI with BDO as HSs and PTMG with a relatively high molecular weight of 2000 g·mol –1 as SSs without introducing other chemical bonds, such as disulfide bond, transition metal complexation, borate ester, etc.…”

Section: Resultsmentioning

confidence: 86%

“…(b) Stress–strain curves of three samples of HMDI-based TPUs with different molecular weights of 1000 and 2000 g·mol –1 in PTMG segments. (c) Ashby plot of “tensile strength” and “elongation at break” of PTMG 2k -HMDI 2.5 and other PTMG-based TPUs reported in the literature. ,,,,,− …”

Section: Resultsmentioning

confidence: 99%

Robust Stretchable Thermoplastic Polyurethanes with Long Soft Segments and Steric Semisymmetric Hard Segments

Zhang

2020

Ind. Eng. Chem. Res.

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Thermoplastic polyurethane (TPU) elastomers based on polyoxytetramethylene glycol (PTMG) with 2000 g·mol–1 as soft segments (SSs) and isocyanates as well as their reaction with butanediol as hard segments (HSs) were synthesized. The three-dimensional supramolecular networks were constructed in TPU by the formation of physical HSs-rich domains via microphase separation, hydrogen bonding, and microcrystallization, which are dominated by the chemical structure of HSs. The robust stretchable TPU with an excellent tensile strength of 32 MPa and elongation of 1378% at break could be successfully prepared, and no crystallization happened to keep the elasticity even at a low temperature (−90 °C) when the steric semisymmetric bis(4-isocyanatocyclohexyl)methane (HMDI) was introduced into HSs-rich domains. The crystallinity and ordered hydrogen bonding content decreased in HSs-rich domains with increases in steric hindrance and asymmetry of diisocyanates. A new approach was developed to construct the high-performance TPUs by introducing long PTMG SSs for the flexibility and elasticity and steric semisymmetric HMDI hard segments.

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Effect of chain extender length and molecular architecture on phase separation and rheological properties of ether-based polyurethanes

Pourmohammadi‐Mahunaki

Haddadi‐Asl

Roghani‐Mamaqani

et al. 2021

Polym. Bull.

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Effect of soft/hard segments in poly (tetramethylene glycol)-Polyurethane for water barrier film

Cited by 28 publications

References 10 publications

Evaluation of Polyurethane Elastomers for Encapsulation of Hydroacoustic Transducers

Evaluation of Polyurethane Elastomers for Encapsulation of Hydroacoustic Transducers

Robust Stretchable Thermoplastic Polyurethanes with Long Soft Segments and Steric Semisymmetric Hard Segments

Effect of chain extender length and molecular architecture on phase separation and rheological properties of ether-based polyurethanes

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