Preparation of monodisperse polyethylene oxides by gel permeation chromatography of discontinuous polymer-homologous series

Abstract Starting from triethylene glycol, monodisperse polyethylene oxides of a molecular weight (MW) up to 2000 (degree of polymerisation (DP) During the first step the ditosylate of triethylene glycol is reacted with the sodium alkoxide of the same diol at room temperature. The condesation product (polymer homologues of triethylene glycol) was separated by molecular distillation and yielded the pure oligomers nonaethylene glycol (DP = 9, MW 414) and pentadecaethylene glycol (DP = 15, MW = 678), as proved by gel chromatography. During the next step the polymer homologues of nonaethylene glycol were synthesised in a similar way. The pure oligomers hepteicosa (DP = 27, MW = 1207) and pentat…

Gelchromatographie. 7. Mitt.: Die auflösung bei der trennung von oligomeren

Die optimalen Bedingungen und die Anwendungsgrenzen der Gelchromatographie zur Trennung von Gemischen in Einzelkomponenten werden diskutiert. Die Wahl eines Gels mit geeigneter Porengrosenverteilung hat einen entscheidenden Einflus auf die erzielbare Trennung. Niedermolekulare Polystyrole, Polybutylmethacrylate, Polyathylenoxide, Polyexpoxide und verschiedene Tenside werden getrennt. Eine polymerhomologe Reihe last sich etwa bis zum Polymerisationsgrad 15 in einzelne Glieder trennen; bis zum Polymerisationsgrad 30 sind in den Schreiberkurven nicht vollstandig aufgeloste Peaks zu erkennen. Optimal conditions and limits of application for gelchromatographic separation of mixtures into signle …

The reaction of ethylene glycol, 1,4-butanediol, 1,6-hexanediol, 3,6-dioxaoctane-1,8-diol (triethylene glycol), poly(ethylene oxide)s with Mn = 300,1000 and 3000, or with poly(propylene oxide)s with Mn = 425 and 2000 in excess with AIBN leads to the corresponding bis(hydroxyalkyl) 2,2′-azodiisobutyrates (1a–i). These initiators are suited to synthesize telechelics. With equimolar amounts of AIBN and 3-oxapentane-1,5-diol (diethylene glycol), poly(ethylene oxide)s with Mn = 300, 1000 and 12000, poly(propylene oxide) with Mn = 425, or with poly(tetrahydrofuran) with Mn = 1000 and 2000 polymeric azoinitiators of structure 2 are formed. Blockcopolymers may be synthesized by means of these polym…