Aspartate-based polyurea coatings: ambient cure process and inevitable transformation of urea groups into hydantoin cycles in polyurea networks and their impact on film properties

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389013%3A_____%2F24%3A00585865" target="_blank" >RIV/61389013:_____/24:00585865 - isvavai.cz</a>

Alternative codes found

RIV/00216208:11320/24:10491351

Result on the web

<a href="https://www.sciencedirect.com/science/article/pii/S0300944024002418?via%3Dihub" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0300944024002418?via%3Dihub</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.porgcoat.2024.108449" target="_blank" >10.1016/j.porgcoat.2024.108449</a>

Result language

angličtina

Original language name

Aspartate-based polyurea coatings: ambient cure process and inevitable transformation of urea groups into hydantoin cycles in polyurea networks and their impact on film properties

Original language description

Polyurea protective coatings have gained large interest from research and application in coating and gel polyelectrolyte areas due to their durability, excellent thermal, and mechanical stability, and the possibility of cure without the use of any catalyst or solvent. In this study, we address a chemical mechanism of the aspartate amine–isocyanate cure that involves an unexpected transition of urea bonds into hydantoin bonds. Three aspartic esters (ASPEs) with varying chemical structures were used to study model high-solid (≥60 wt.-% solid content) polyurea coatings. Two linear aliphatic ASPEs with flexible backbones that were prepared using the aza-Michael addition, and a commercial cycloaliphatic aspartic ester (Desmophen® NH 1420) were used as polyurea-based network precursors and were crosslinked with the plant-based tri-isocyanate Desmodur® eco N 7300. The coatings were cured under ambient conditions, and the effect of the molecular structure, chain length of ASPE, cure time, and the simultaneous chemical crosslinking and solvent evaporation on the coating properties were thoroughly investigated. The chemical changes that occurred throughout the film depths were analyzed by FTIR and Raman confocal microscopy. The study revealed the inherent transformation of urea bonds to substituted hydantoin rings. The intensity of transformation depended on the mobility of the polyurea network chain segments in ASPEs. The thermal and mechanical properties characterized by DSC, TGA, uniaxial tensile test, and microindentation hardness test showed the softening effect of the hydantoin group on the networks effective within weeks after the NCO primary cure.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10404 - Polymer science

Project

—

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2024

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Progress in Organic Coatings

ISSN

0300-9440

e-ISSN

1873-331X

Volume of the periodical

192

Issue of the periodical within the volume

July

Country of publishing house

NL - THE KINGDOM OF THE NETHERLANDS

Number of pages

22

Pages from-to

108449

UT code for WoS article

001239509200001

EID of the result in the Scopus database

2-s2.0-85192236016