Reactivity of hydroxyl end groups in a series of low molecular weight polyesters

Valuyev, V.I.; Shlayakhter, R.A.; Apukhtina, N.P.; Тигер, Р. П.; Èntelis, S.G.; Korol'kova, Z.S.

doi:10.1016/0032-3950(67)90346-2

Cited by 17 publications

(2 citation statements)

References 10 publications

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“…However, studying the effect of molecular weight of hydroxyl‐terminated oligoesters on their reactivity with isocyanates, other authors19 have found the decrease of the second‐order rate coefficients with increasing molecular weight of poly(diethylene glycol) adipate in uncatalyzed reaction with phenyl isocyanate ([NCO] = [OH] = 0.1 equiv/L) in chlorobenzene at 110 °C: …”

Section: Resultsmentioning

confidence: 99%

Fluoropolyethers end‐capped by polar functional groups. IV. A novel approach to the evaluation of reactivities of hydroxy‐terminated ethoxylated fluoropolyethers in the tin(IV)‐catalyzed reactions with isophorone diisocyanate

Khomko

Mashlyakovskiy

Tonelli

2004

J. Polym. Sci. A Polym. Chem.

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The effect of catalyst dibutyltin dilaurate (DBTDL) on the kinetics of urethane formation reactions of ␣,-bis(hydroxy)-terminated fluoropolyethers Fomblin ® Z-DOL TXs (FPEs) of various molecular weights and poly(oxyethylene) glycol PEG-400 with isophorone diisocyanate (IPDI) in hexafluoroxylene (HFX) and tetrahydrofuran (THF) at 40°C and NCO:OH ϭ 2:1 have been studied in a broad range of catalyst (0.10 -9.00) ϫ10 Ϫ4 M and total reagents (10.0 -60.1 wt %) concentrations. The rate of tin-catalyzed second-order reactions (with respect to diol and diisocyanate) was found to be proportional to the square root of catalyst concentration [DBTDL] 0.5 both in low polar (HFX) and polar (THF) solvents. Effect of catalyst saturation was revealed for all the reaction systems at higher DBTDL concentrations as well as the appearance of the limiting catalyst concentrations C lim below which the rates of reaction were close to zero. Based on these findings new effective rate coefficients have been derived kЈ eff ϭ k cat /(C cat 0.5 Ϫ C lim 0.5 ) that are independent of the total reagent concentration in the range of 10.0 -60.1 wt % ([OH] ϭ 0.10 -0.91 equiv/L). This new approach highlights that the rate of the tin-catalyzed urethane formation reactions of ␣,-bis(hydroxy)terminated fluoropolyethers Z-DOL TXs with IPDI in HFX at 40°C and NCO:OH ϭ 2:1 increases significantly with increasing MW of FPE from 776 up to 3405.

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Section: Resultsmentioning

confidence: 99%

Fluoropolyethers end‐capped by polar functional groups. IV. A novel approach to the evaluation of reactivities of hydroxy‐terminated ethoxylated fluoropolyethers in the tin(IV)‐catalyzed reactions with isophorone diisocyanate

Khomko

Mashlyakovskiy

Tonelli

2004

J. Polym. Sci. A Polym. Chem.

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“…At the same time, rate of reaction IPDI catalyzed by DBTDL, with PBA exceeds PCL at 1.4 and 3 times, respectively. That difference in oligoesterdiols reactivity can be explained by the distinction of rotational isomeric forms, or conformations, of their molecules in acetone[17], which significantly affect the molecular organization of the solution.…”

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confidence: 99%

Kinetic Features of Isophorone Diisocyanate and Oligoesterdiols Reaction under Waterborne Polyurethane Synthesis Conditions and the Preparation of the Polymer Dispersions

Karpov

Dzhalmukhanova²,

Chernyayev³

et al. 2020

KEM

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Kinetics of urethane formation from isophorone diisocyanate and polycaprolactone diol and poly(butylene adipate) in acetone was studied by IR spectroscopy. It was found that poly(butylene adipate) is the most reactive oligoesterdiol, with the reaction being both non-catalyzed and catalyzed by dibutyltin dilaurate. It was shown that the cycloaliphatic group of isophorone diisocyanate is an order of magnitude more active than the aliphatic one in catalytic reactions of isophorone diisocyanate with investigated oligoesterdiols. Furthermore, waterborne polyurethanes based on the studied oligoesterdiols were synthesized and characterized by DLS, DSC, and TGA methods.

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Copolymères séquencés poly(oxyéthylène)/poly(oxyéthylène‐oxyadipoyl) à charnières uréthane

Galin

1972

Makromol. Chem.

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R~S U M~:Nous avons 6tudit la cinetique de la reaction du bis(4-isocyanatop1i~nyl)mtthane (MDI) et du 1-mtthyl-2.4-diisocyanatobenzbne (2.4-TDI) sur le poly(oxytthy1tne) (POE, an = 2 750) et le poly(oxytthyltneoxyadipoy1) (PAE, wn = 2 350) en solution dans le tolubne ou le dioxanne, et pour un rapport constant [NCO]/[OH] = 2. I1 est possible d'obtenir, dans des conditions exptrimentales bien dttermintes, des aprepolymbres>> porteurs de groupements terminaux isocyanate. Ces ccprBpolymtress prtsentent cependant une stabilitt limitte dans le temps, qui se manifeste par un accroissement de la masse moltculaire moyenne et de la fonctionnalitt, risultant de la formation de liaisons allophanate intermoltculaires. Ce processus est en particulier acctltrt dans le cas des POE.La polycondensation en solution Iiomoghe entre ((prkpolymbren PAE w.w'-diisocyanate et POE conduit 1 des copolymhes sequences lineaires, dans lesquels le nombre moyen de sequences (3 1 2 0 ) et la longueur de la sequence POE (2750 < %, , < 10600) peuvent varier dans un assez large domaine. L'architecture de ces macromoltcules est caractiriste par l'alternance rtgulibre de sequences hydrophobes PAE et hydrophiles POE reliies entre elles par des charnibres urtthane. Ces mattriaux constituent des modtles inttressants dans le domaine des copolymtres stquencts cristallisables douts de proprittts amphipatiques, et dans celui des 6lastombres polyurtthane. ZUSAMMENFASSUNG:Es wurde die Kinetik der Reaktion des Bis(4-isocyanatophenyl)methans (MDI) und des 1-Methyl-2.4-diisocyanatobenzols (2.4-TDI) mit Poly(oxyathy1en) (POE, mn = 2 750) sowie mit Poly(oxyathylenoxyadipoy1) (PAE, xn = 2 350) in Toluol oder Dioxan bei konstantem Verhaltnis [NCO]/[OH] = 2 untersucht. Bei Wahl bestimmter experimenteller Bedingungen konnen ,,Prapolymere" mit Isocyanat-Endgruppen erhalten werden. Die Stabilitat dieser Polynieren ist jedoch begrenzt. Eine Nebenreaktion fuhrt zur Erhohung des Molekulargewichtes und zur Bildung neuer funktioneller Gruppen, als Folge der Bildung intermoleknlarer Allophanat-Bindungen. Dieser Prozen verliuft schneller im Falle des POE als im Falle des PAE. Die Polykondensation eines ,,Prapolymeren", PAE, w.w'-Diisocyanats und eines POE fuhrt zu linearen Block-Copolymeren, in denen die mittlere Zahl der Sequenzen (3 bis 20)sowie die Lange der POE-Sequenzen weitgehend (2 750 < xn < 10 600) variieren konnen.Die Struktur dieser Polymeren ist charakterisiert durch regelmaeiges Alternieren hydrophober PAE-und hydrophiler POE-Blocke, die durch Urethanverbindungen miteinander verbunden sind. Diese Produkte sind interessante Modelle auf dem Gebiet kristallisierbarer amphipatischer Block-Copolymerer und der Polyurethan-Elastomeren.

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Reactivity of hydroxyl end groups in a series of low molecular weight polyesters

Cited by 17 publications

References 10 publications

Fluoropolyethers end‐capped by polar functional groups. IV. A novel approach to the evaluation of reactivities of hydroxy‐terminated ethoxylated fluoropolyethers in the tin(IV)‐catalyzed reactions with isophorone diisocyanate

Fluoropolyethers end‐capped by polar functional groups. IV. A novel approach to the evaluation of reactivities of hydroxy‐terminated ethoxylated fluoropolyethers in the tin(IV)‐catalyzed reactions with isophorone diisocyanate

Kinetic Features of Isophorone Diisocyanate and Oligoesterdiols Reaction under Waterborne Polyurethane Synthesis Conditions and the Preparation of the Polymer Dispersions

Copolymères séquencés poly(oxyéthylène)/poly(oxyéthylène‐oxyadipoyl) à charnières uréthane

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