Effect of surface modification of colloidal silica nanoparticles on the rigid amorphous fraction and mechanical properties of amorphous polyurethane–urea–silica nanocomposites

Oğuz, Oğuzhan; Candau, Nicolas; Bernhard, Stéphane; Söz, Çağla Koşak; Heinz, Özge; Stochlet, Grégory; Plummer, C. J. G.; Yılgör, Emel; Jonáš, Alexandr; Menceloǵlu, Yusuf́ Z.

doi:10.1002/pola.29529

Cited by 7 publications

(8 citation statements)

References 84 publications

(136 reference statements)

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“…The copolymers were synthesized by the two-step polymerization technique, also known as the prepolymer method. The detailed procedure followed was previously reported by our group. − All reactions were performed in 500 mL three-necked round-bottom Pyrex reaction flasks equipped with a mechanical overhead stirrer, a thermometer and a funnel, with temperature control provided by a heating mantle. The isocyanate-terminated PEO prepolymer solution in THF with 50 wt % solids content was prepared at 60 °C.…”

Section: Methodsmentioning

confidence: 99%

Geometric Confinement Controls Stiffness, Strength, Extensibility, and Toughness in Poly(urethane–urea) Copolymers

et al. 2021

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Achieving a unique combination of stiffness, strength, extensibility, and toughness in sol-cast poly(urethane−urea) (PU) copolymer films is a challenge since these properties arein general mutually exclusive. Here we demonstrate that geometric confinement of the basic building blocks controls stiffness, strength, extensibility, and toughness in PU films. Our results suggest that the severity of geometric confinement can be tuned by adjusting (i) soft segment molecular weight (SSMW) and (ii) drying temperature (DT) thanks to their effects on the structure formation via microphase separation and/or (confined and/or bulk) crystallization. It is therefore possible to produce (i) soft (no notable confinement) and (ii) stiff, strong, extensible, and tough (severe confinement) materials without changing any other parameter except SSMW and DT. The former has a typical physically cross-linked network and shows a welldefined elastomeric behavior with an elastic modulus (E) of 5−20 MPa, a tensile strength (σ max ) of 30−35 MPa, an extensibility (ε) of 1000−1300%, and a toughness (W) of 90−180 MJ m −3 . The latter, on the other hand, possesses an elegant hierarchical structure containing tightly packed secondary structures (7 2 -helix, 4 1 -helix, and antiparallel β-sheets) and displays an elastoplastic behavior with an E of 400−700 MPa, a σ max of 45−55 MPa, an ε of 650−850%, and a W of 200−250 MJ m −3 . Hence, our findings may be of interest in designing advanced materials containing synthetic replica of the secondary structures found in protein-based materials. The structure formation in the materials with this structural hierarchy is driven by the confined crystallization of helical poly(ethylene oxide) (PEO) chains in subnanometer urea channels, whichto the best of our knowledgeis a phenomenon wellknown in host−guest systems but has not yet demonstrated in PU copolymers, and complemented by the "bulk" crystallization of PEO and/or the microphase separation.

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Section: Methodsmentioning

confidence: 99%

Geometric Confinement Controls Stiffness, Strength, Extensibility, and Toughness in Poly(urethane–urea) Copolymers

et al. 2021

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“…Among SMPs, thermoplastic polyurethanes − (TPUs), that is, segmented polyurethane, polyurea, and poly(urethane–urea) (PU) copolymers, have received considerable attention due to the large design space offered by urethane–urea chemistry, promising practically unlimited numbers of macromolecular architectures with various programmable shape-memory capabilities. A large number of studies on stimuli-responsive TPUs with various shape-memory functions are available in the literature. − Some studies more specifically focus on the effects of structural design parameters on the shape-memory capabilities of TPUs , or their use in different forms and/or applications. , TPUs are, in general, physically cross-linked networks of linear macromolecules consisting of soft and hard segments (HSs). In shape-memory applications, soft segments (SSs) are employed as switching domains, whereas HSs serve as netpoints that provide stability and enforce the permanent shape of the material.…”

Section: Introductionmentioning

confidence: 99%

Stiff, Strong, Tough, and Highly Stretchable Hydrogels Based on Dual Stimuli-Responsive Semicrystalline Poly(urethane–urea) Copolymers

Candau

Stoclet

Tahon

et al. 2021

ACS Appl. Polym. Mater.

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There has been a considerable interest in developing stiff, strong, tough, and highly stretchable hydrogels in various fields of science and technology including biomedical and sensing applications. However, simultaneous optimization of stiffness, strength, toughness, and extensibility is a challenge for any material, and hydrogels are well-known to be mechanically weak materials. Here, we demonstrate that poly(ethylene oxide)-based dual stimuli-responsive semicrystalline poly(urethane−urea) (PU) copolymers with high hard segment contents (30 and 40%) can be utilized as stiff, strong, tough, and highly stretchable hydrogels with an elastic modulus (4−10 MPa) tens to hundreds of times higher than that of conventional hydrogels (0.01−0.1 MPa), strength (7−13 MPa) and toughness (53−74 MJ• m −3 ) fairly comparable to those of the toughest hydrogels reported in the literature, and stretchability beyond 10 times their initial length (1000−1250%). In addition, the shapememory program has been used to tune the room temperature stiffness and strength of the studied PU copolymers. Finally, the materials show fast shape recovery (less than 10 s) during both heat-and water-activated shape memory cycles, which can be adjusted by a simple modulation of the hard segment content and/or soft segment molecular weight. Our findings may be of interest in emerging biomedical and sensing applications.

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“…After the external force is released, the molecular chain spontaneously returns to the curled form and elastic recovery occurs. In the molecular structure of CPUF, the large-molecular-weight diol units offer elasticity, while the crystalline part of the hard segments makes the elasticity of the soft segments occur in a confined area, avoiding the relative slips of molecular chains and as such the stress relaxation …”

Section: Resultsmentioning

confidence: 99%

“…In the molecular structure of CPUF, the large-molecular-weight diol units offer elasticity, while the crystalline part of the hard segments makes the elasticity of the soft segments occur in a confined area, avoiding the relative slips of molecular chains and as such the stress relaxation. 18 Figure 6 illustrates the tensile recovery curves of CPUF and MPUF at a 300% elongation, from which the 300% elastic recovery ratio and the stress attenuation ratio were studied, as given in Table 4. It can be seen that MPUF had a 300% elastic recovery ratio lower than CPUF because, with the addition of poly(HDMI-TBDEA), the molecular chains slipped after strain generation, which reduced the internal energy stored in the molecular chain, and could not be recovered after the external force was removed.…”

Section: X-ray Diffractionmentioning

confidence: 99%

Polyurethanes Based on Dicyclohexylmethane 4,4′-Diisocyanate and N-tert-Butyldiethanolamine for Enhancing the Dyeability of Fiber toward Acid Dye

Jing

Miao

et al. 2023

ACS Appl. Polym. Mater.

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Conventional polyurethane fiber (CPUF) has been widely used in clothes, but it is difficult to color CPUF into a deep hue with acid dyes. In this work, it is proposed that polyurethane is synthesized using dicyclohexylmethane-4,4′-diisocyanate (HMDI) and N-tert-butyldiethanolamine (TBDEA), named poly(HMDI-TBDEA), and is added to a CPUF spinning solution to prepare a modified polyurethane fiber (MPUF) which has an enhanced dyeability toward acid dyes. It is assumed that poly(HMDI-TBDEA) brings tertiary amine groups and tert-butyl groups to MPUF, of which the tertiary amine groups can be protonated under acidic conditions and electrostatically adsorbs anionic ions of acid dyes, and the tert-butyl groups disrupt the ordered arrangement of hard segments in polyurethane to increase the accessible area for acid dyes. The synthesis of poly(HMDI-TBDEA) was validated by proton and carbon nuclear magnetic resonance spectroscopy (1H and 13C NMR) and gel permeation chromatography. MPUF was characterized by differential scanning calorimetry, thermogravimetry, X-ray diffraction, and the tensile test. The study revealed that the addition of poly(HMDI-TBDEA) disrupted the ordered arrangement of the hard segments and strengthened the soft segments but had no obvious influence on the thermal stability. In comparison with CPUF, MPUF exhibited approximately the same elastic recovery, despite a drop in the elongation at break and the break strength. The zeta potential test demonstrated that MPUF might be protonated for enhanced electropositivity under acidic conditions. MPUF displayed superior dyeability than CPUF when dyed with C.I. Acid Orange 7 at pH 3.

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Effect of surface modification of colloidal silica nanoparticles on the rigid amorphous fraction and mechanical properties of amorphous polyurethane–urea–silica nanocomposites

Cited by 7 publications

References 84 publications

Geometric Confinement Controls Stiffness, Strength, Extensibility, and Toughness in Poly(urethane–urea) Copolymers

Geometric Confinement Controls Stiffness, Strength, Extensibility, and Toughness in Poly(urethane–urea) Copolymers

Stiff, Strong, Tough, and Highly Stretchable Hydrogels Based on Dual Stimuli-Responsive Semicrystalline Poly(urethane–urea) Copolymers

Polyurethanes Based on Dicyclohexylmethane 4,4′-Diisocyanate and N-tert-Butyldiethanolamine for Enhancing the Dyeability of Fiber toward Acid Dye

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