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001-es BibID:	BIBFORM079608
035-os BibID:	(Scopus)85021695084 (WoS)000406962300002
Első szerző:	Nagy Lajos (vegyész)
Cím:	Kinetics of Uncatalyzed Reactions of 2,4'- and 4,4'-Diphenylmethane-Diisocyanate with Primary and Secondary Alcohols / Lajos Nagy, Tibor Nagy, Ákos Kuki, Mihály Purgel, Miklós Zsuga, Sándor Kéki
Dátum:	2017
ISSN:	0538-8066
Megjegyzések:	The kinetics of the uncatalyzed reaction of an industrially important 50/50blend of isomers of 4,4·-diphenylmethane-diisocyanate (4,4-MDI) and 2,4·-diphenylmethane-diisocyanate (2,4·-MDI) with primary and secondary alcohols was studied using high-performance liquid chromatography coupled with photodiode array detector. The alcoholssuch as 1-propanol, 2-propanol, 1-hexanol, 2-hexanol, 3-hexanol, 1-methoxy-2-propanol, and3-methoxy-1-propanol were used in high molar excess to diisocyanate in toluene at 80?C, andpseudo?first-order dependences on the concentrations of 4,4·-MDI and 2,4·-MDI were found.Appropriate treatments of the kinetic data allowed us to determine the corresponding pseudo?first-order rate constants. According to the kinetic results, the reactivity of the isocyanate groupin the para-position is about four to six times higher than that of the ortho-positioned iso-cyanate group, depending on the reacting alcohol. Furthermore, the substitution effect, i.e.,change in the reactivity of the free isocyanate group after the other has been reacted, was foundfor both 4,4·-MDI and 2,4·-MDI isomers. The differences in the reactivities of the isocyanategroups of 2,4·-MDI and 4,4·-MDI isomers before and after one of two isocyanate groups hasbeen reacted are explained in terms of partial positive charges on the corresponding carbonylcarbon atom calculated by high-level quantum chemical calculations. In addition, the UV-spectral properties of the products obtained by quenching the reactionmixture with methanol are also discussed in light of practical implications.
Tárgyszavak:	Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk
Megjelenés:	International Journal of Chemical Kinetics. - 49 : 9 (2017), p. 643-655. -
További szerzők:	Nagy Tibor (1988-) (vegyész) Kuki Ákos (1966-) (villamosmérnök) Purgel Mihály (1982-) (vegyész) Zsuga Miklós (1944-) (polimer kémikus) Kéki Sándor (1964-) (polimer kémikus)
Pályázati támogatás:	GINOP-2.3.2-15-2016-00041 GINOP ÚNKP-16-3 Egyéb K-116465 egyéb
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
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