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Efficient Inhibition of Re‐blocking During the Deblocking of Blocked Isocyanates
Author(s) -
Aso Fumihiro,
Masuda Kohei
Publication year - 2020
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.202002817
Subject(s) - chemistry , isocyanate , silane , ketone , blocking (statistics) , decomposition , aryl , combinatorial chemistry , polymer chemistry , polyurethane , organic chemistry , statistics , alkyl , mathematics
Abstract 3‐Silylpropanols bearing allyl or aryl groups on the silicon atom were found to act as isocyanate blocking agents that can allow to deblock with efficient inhibition of re‐blocking. As a result of the inhibition, the isocyanates blocked by 3‐silylpropanols showed an exceptional lower deblocking temperature than by a conventional aliphatic alcohol. The inhibition is based upon the decomposition reaction of 3‐silylpropanols to a 5‐membered cyclic silane and propylene or arene, where β‐silyl cation intermediates may play a key role. The new blocked isocyanates can tolerate water, whereas previously well‐known low‐temperature‐deblockable agents, such as methylethyl ketone oxime (MEKO), are not generally compatible with water.