The cationic ring-opening polymerzation of 1,3,dtrioxocane (TO) in presence of benzyl alcohol occurs in accordance with the activated monomer mechanism. In addition to their molecular weight distribution the reaction products exhibit a distribution of their end-functionality caused by transacetalization. livo-dimensional chromatography, including size-exclusion and highperformance liquid chromatography, was used to characterize quantitatively the molecular weight and functionality distribution. The postulated mechanism leading to a functionality distribution is supported by the experimental results obtained.0 1990, HUthig & Wepf Verlag, Base1CCC 0025-1 16X/90/%03.00
Poly(alky1ene adipate)diols having molar masses of 1500,2000 and 3000 were stored at temperatures of 25 and 60 "C in the presence of low amounts of different alcohols and some polyurethane (PUR) catalysts, such as dibutyltindilaurate (DBTL),
Die HClO4‐initiierte Polymerisation von 1,3‐Dioxepan (DE) in Gegenwart von Poly(ethylenglycol) (M̄n = 600 g/mol, PEG 600) verläuft unter Übertragung auf die OH‐Gruppen des Poly(ethylenglycols). Es werden Blockcopolymere gebildet. Durch protoneninitiierte Spaltungs‐ und Neuverknüpfungsreaktionen an den acetalischen Sauerstoffatomen kommt es zur Bildung von DE‐Homopolymeren und Blockcopolymeren mit mehr als einer PEG 600‐Struktureinheit im Molekül. Diese Austauschreaktionen führen dazu, daß sich letztlich die als statistisch am wahrscheinlichsten anzusehende mittlere Struktur herausbildet.
Dilute solutions of poly/6-[4-(4-methoxyphenoxycarbonyl)phenoxy]hexyl methacrylate) (1 a, structure-based IUPAC name poly(l-(6-[4-(4-methoxyphenoxycarbonyl)phenoxy]hexyloxycar-bonylJ-1 -methylethylene)) were investigated by means of size-exclusion chromatography (SEC), osmometry, light scattering, and viscometry. It was found that the universal calibration of SEC is not valid with this polymer and that dilute solution properties (intrinsic viscosity, second virial coefficient) are at variance with predictions from the two-parameter theory of polymer solutions. The latter discordance is explained on the basis of the theory of hydrodynamic properties of wormlike chains which takes into account the effective diameter of the chain. The characteristic ratio (C, = 15,l) and the Kuhn segment length (A-' = 28. lo-' cm) were estimated. The polymer-solvent interaction parameter was shown to decrease in the series of solvents: 1,1,2,2-tetrachloroethane, chloroform, tetrahydrofuran, N,N-dimethylformamide. The interaction of the solvents with the side groups was shown to be the determining factor. a) Structure-based IUPAC name: poly(l-(6-[4-(4-methoxyphenoxycarbonyl)phenoxy]hexyloxy-carbonylJ-1 -methylethylene). 0 1993, Hiithig & Wepf Verlag, Basel CCC 0025-1 16X/93/$05.00
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