Structure and properties of segmented poly(urethaneurea)s with relatively short hard-segment chains

Sakurai, Shinichi; Sakaue, Harunori; Nakamura, Takeshi; Banda, Lameck; Nomura, Shunji

doi:10.1002/1099-0488(20000701)38:13<1716::aid-polb50>3.0.co;2-x

Cited by 23 publications

(8 citation statements)

References 35 publications

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“…Materials. The poly(urethane-urea) (PUU) used in this study was synthesized using a procedure similar to that described by Sakurai et al 49 In this procedure, 4,4′-diphenylmethane diisocyanate (MDI) was reacted with poly(tetramethylene oxide) (PTMeO, M W ) 1800 g/mol) to form the prepolymer with diisocyanate end caps, which was subsequently dissolved in N,N-dimethylacetamide (DMAc). 1,2-Ethylenediamine (EDA) and diethylamine (DEA) were added to the prepolymer solution, where EDA was the chain extender and DEA was the chain terminator.…”

Section: Methodsmentioning

confidence: 99%

In-Situ Studies of Structure Development during Deformation of a Segmented Poly(urethane−urea) Elastomer

Yeh¹,

Hsiao²,

et al. 2003

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The structural development of a segmented poly(urethane-urea) (PUU) elastomer containing a low concentration of hard segment during deformation was studied by simultaneous mechanical and optical measurements (rheooptical techniques). Specifically, in-situ wide-angle X-ray diffraction and smallangle X-ray scattering using synchrotron radiation and time-resolved Fourier transform infrared spectroscopy were applied to investigate the segmental orientation of PUU chains during cyclic elongation and recovery. Formation of two different domain microstructures is characterized with changes in strain. These microstructures consist of lamellar hard domains and highly stressed nanofibrils consisting of alternating hard and crystalline soft domains. By comparing the X-ray scattering and vibrational spectroscopic data, a morphological model of hard-and soft-segment microphase separation, orientation, and strain-induced crystallization in the soft segments was obtained.

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Section: Methodsmentioning

confidence: 99%

In-Situ Studies of Structure Development during Deformation of a Segmented Poly(urethane−urea) Elastomer

Yeh¹,

Hsiao²,

et al. 2003

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“…The properties for the pure PUU film agreed well with the literature values of high ductility that report elongations at break over 800%. 36 In fact, the films prepared in this study were so stretchable that they did not break inside the strain limits of the UniVert test stand, which has a practical maximum extension of <35 mm (Table 1 and Figures 3 and S14). In addition, films returned to their original size upon relaxation, as expected for an elastomer.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Strong, Ductile MOF–Poly(urethane urea) Composites

et al. 2021

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Metal–organic framework (MOF)–polymer hybrid materials have been investigated for use in personal protective equipment (PPE) for combating chemical threats. However, few of these composite materials have demonstrated the desired processability or balance of strength and ductility suitable for modern textiles. In this work, a poly(urethane urea) (PUU) polymer was synthesized to mimic solution-processable spandex for MOF composites that have combined advantages for both the force the composite can withstand (strength) and the ability of the material to deform under strain (ductility). UiO-66/PUU mixed matrix membranes (MMMs) with up to 50 wt % UiO-66 MOF showed both high strength and ductility. UiO-66 and UiO-66-NH2 MMMs with PUU mechanically outperformed previously studied 50 wt % MOF/poly(vinylidene difluoride) (PVDF) MMMs. Testing of MMMs against the chemical warfare agent simulant dimethyl-4-nitrophenylphosphate (DMNP) revealed that the polymer plays an important role, with UiO-66-NH2/PUU MMM showing the fastest hydrolysis rate. Ductile fibers of 50 wt % UiO-66 and UiO-66-NH2 PUU composites were successfully prepared and showed remarkable handling properties and activity toward DMNP hydrolysis with 50 wt % UiO-66-NH2/PUU fibers performing better than any of the MMMs tested. These MOF–polymer composites could also be electrospun into nanofiber mats, which further illustrates the diverse range of processing techniques available for these materials.

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“…Considering that the ambient temperature is higher than the melting points of the PTMO segment, the PTMO chains in the original state are assumed to be in random coil conformations, i.e., Gaussian chains. This assumption was successfully employed for PTMO in PUU, 65 PTMO in T4T-PTMO copolymers, 66 and PBT-PTMO copolymers. 67 The unperturbed root-mean-square end-to-end distance of PTMO can be calculated by eq 11.…”

Section: ■ Experimental Sectionmentioning

confidence: 99%

Reversible–Irreversible Transition of Strain-Induced Crystallization in Segmented Copolymers: The Critical Strain and Chain Conformation

Zhu

Zhou

Wang

et al. 2021

ACS Appl. Polym. Mater.

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The formation, growth, and melting of the strain-induced crystallization (SIC) structures of poly(tetramethylene oxide) (PTMO) were studied during the step-cycle deformation of poly(ether-b-amide) (PEBA) elastomers by Fourier transform infrared (FTIR) spectroscopy, wide-angle X-ray diffraction (WAXD), and small-angle X-ray scattering (SAXS). Whether SIC structures can either completely fuse or partially persist upon full relaxation of the stress depends on the maximum strain before sample retraction. After small and medium strains, the SIC can fully melt, i.e., reversible SIC. SIC can be partially retained after larger strain, i.e., irreversible SIC, which resulted from not only a higher equilibrium melting point but also a substantially higher plastic strain. For the reversible−irreversible transition, at the critical strain, PTMO chains of the soft segment were extended fully with all-trans zig-zag conformation after the lamellae of the hard segment completely fractured and greatly aligned. The three-stage microscopic model about the PEBA deformation proposed in our previous paper [Zhu, P.et al. Strain-induced Crystallization of Segmented Copolymers: Deviation from the Classic Deformation Mechanism. Macromolecules 2017, 50, 3911 3921] was improved by adding a more detailed description of the SIC behaviors for the stage between the onset strain and the critical strain, as well as for the stage after the critical strain. The findings could help design elastomers with high tensile strengths and low residual strains.

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Structure and properties of segmented poly(urethaneurea)s with relatively short hard-segment chains

Cited by 23 publications

References 35 publications

In-Situ Studies of Structure Development during Deformation of a Segmented Poly(urethane−urea) Elastomer

In-Situ Studies of Structure Development during Deformation of a Segmented Poly(urethane−urea) Elastomer

Strong, Ductile MOF–Poly(urethane urea) Composites

Reversible–Irreversible Transition of Strain-Induced Crystallization in Segmented Copolymers: The Critical Strain and Chain Conformation

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