Lysine‐based functional blocked isocyanates for the preparation of polyurethanes provided with pendant side groups

Yin, Jie; Wildeman, Jur; Loontjens, Ton

doi:10.1002/pola.27658

Cited by 7 publications

(5 citation statements)

References 50 publications

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“…Thermoplastic polyurethane (TPU) 1–4 is a linear polymer composed of diisocyanate, low molecular weight glycol and chain extender. TPU is widely used in all aspects of life, which combines the thermoplasticity of plastic and the high elasticity of rubber, and has excellent wear resistance and solvent resistance 5–7 . As a linear polymer, TPU has a wide adjustment range of hardness and mechanical properties.…”

Section: Introductionmentioning

confidence: 99%

The effect of mixed soft segment on the microstructure of thermoplastic polyurethane

Cui

Wang

Pan

et al. 2021

J of Applied Polymer Sci

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In this work, we fixed the hard segment content (Ch%) and synthesized thermoplastic polyurethane (TPU) elastomers with one‐soft segment (HTPB‐PU, PTMG‐PU, and PCL‐PU) and bi‐soft segment (PTMG‐HPU and PCL‐HPU), using 4,4′‐diphenylmethane diisocyanate, 1,4‐butanediol, and different oligomer diols as raw materials. This work was used to explore the impact of two polar diols (polytetrahydrofuran diol [PTMG]; polycaprolactone diol [PCL]) of the hydroxy‐terminated polybutadiene (HTPB)‐based TPU on the microstructure and macroscopic properties. Using Fourier transform infrared spectroscopy, X‐ray diffraction, and differential scanning calorimetry to characterize TPU, the results showed that the introduction of PCL was better than PTMG in promoting microphase mixing and crystallization, and reducing microphase separation. This result was closely related because the carbonyl group in PCL was stronger than the ether bond in PTMG in forming hydrogen bonds with ─NH bond. Through mechanical test and isopropyl alcohol (IPA) resistance test, the results showed that HTPB‐based TPU with PCL (PCL‐HPU) significantly improved tensile strength and elongation at break, and only a small reduction of Young's modulus was observed. PCL‐HPU had the best retention of the IPA resistance of HTPB‐based TPU.

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Section: Introductionmentioning

confidence: 99%

The effect of mixed soft segment on the microstructure of thermoplastic polyurethane

Cui

Wang

Pan

et al. 2021

J of Applied Polymer Sci

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“…These agents are defined as isocyanates, which have been reacted with a material to prevent its reaction at room temperature with compounds that usually react with isocyanates, but will permit the reaction to occur at higher temperatures . For this purpose, for example, phenols, − oximes, − or lactams − are reacted with isocyanates . This concept is appealing concerning the tuned reactivity and the lower toxicity in the polyurethane synthesis step, but it does not deal with the aspect of the upstream isocyanate formation itself.…”

Section: Introductionmentioning

confidence: 99%

Polythionourethane Thermoset Synthesis via Activation of Elemental Sulfur in an Efficient Multicomponent Reaction Approach

Wolfs

Ribca

Meier

et al. 2023

ACS Sustainable Chem. Eng.

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For the transition toward a safer and more sustainable production of polymeric materials, new synthetic concepts need to be developed. Herein, we describe a catalytic, solvent-free synthesis approach for novel thionourethane thermoset materials, in which the diisothiocyanate reactant is generated in situ via a sulfurization of isocyanides with elemental sulfur, preventing the exposure and handling of the diisothiocyanate. In this one-pot procedure, castor oil fulfills a dual role: (i) acting as the solvent for the in situ diisothiocyanate synthesis in the first step and (ii) reacting as the polyol component in the subsequent thionourethane thermoset formation. The kinetics of the consecutive two steps were studied in detail via real-time IR measurements, and the thermoset crosslinking step was found to be thermally triggerable after the diisothiocyanate reactant is quantitatively formed, enabling high control over the curing process of the system. Differential scanning calorimetry, thermogravimetric analysis, and rheological measurements were performed to investigate the thermal and mechanical properties of the novel thionourethane thermosets and then compared to analogous polyurethane materials. Our results demonstrate an unprecedented approach for thermoset synthesis via an in situ reagent synthesis, i.e., the generation of isothiocyanates from isocyanides by catalytic activation of elemental sulfur, and subsequent thermally triggerable thermosetting with a polyol, resulting in materials with appealing properties.

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“…However, the -NCO is prone to failure in water, and thus IPTS cannot be hydrolyzed and cannot be condensed into polymer coating. In order to solve this problem, caprolactam (CPL) can be used as a blocking agent to block the -NCO, which renders the -NCO inactive at room temperature and able to withstand extended exposure to water without deterioration [39][40][41][42]. Furthermore, the CPL-blocked -NCO can undergo unblocking reaction and release -NCO again at high temperatures.…”

Section: Introductionmentioning

confidence: 99%

A simple method to enhance the interface properties of carbon fibre/polyamide 6 composites: Grafted caprolactam-blocked 3-isocyanatopropyltriethoxysilane on carbon fibre surface

Sun

Zhu

Cai

et al. 2023

Preprint

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Introducing the isocyanate group on the carbon fibre (CF) to improve surface activity is an effective modification method. Still, its application in the industrial field is restricted because the modification process is harmful to the environment and isocyanate is easy to fail. In this paper, 3-isocyanopropyltriethoxysilane (IPTS) has been blocked with caprolactam (CPL) have been prepared. By adjusting the hydrolysis conditions and concentration of the modified coupling agent solution, the CPL-blocked IPTS was grafted to the surface oxidized CF, and the CF-reinforced polyamide 6 (PA6) composites were prepared. After treating CF with 1.0wt% coupling agent solution, the composites’ interlaminar shear strength (ILSS) reached 52.53 MPa, which was 23.83% greater than that of the desized CF/PA6 composites. High-temperature composite molding caused CPL-blocked IPTS to unblock, and the isocyanate that was released thermally intereacted with the terminal amino group of PA6 to establish a high strength interface through covalent grafting, which was the main reason for improving ILSS. This study indicates that this method is safe and simple and can effectively improve the interface properties of CF/PA6 composites.

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Lysine‐based functional blocked isocyanates for the preparation of polyurethanes provided with pendant side groups

Cited by 7 publications

References 50 publications

The effect of mixed soft segment on the microstructure of thermoplastic polyurethane

The effect of mixed soft segment on the microstructure of thermoplastic polyurethane

Polythionourethane Thermoset Synthesis via Activation of Elemental Sulfur in an Efficient Multicomponent Reaction Approach

A simple method to enhance the interface properties of carbon fibre/polyamide 6 composites: Grafted caprolactam-blocked 3-isocyanatopropyltriethoxysilane on carbon fibre surface

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