Polymerization of lactams, XLI. Molecular characterization of linear and branched polycaprylolactam

Abstract

Samples of linear polycaprylolactam have been prepared and fractionated, and the [q]-M, relationship has been established in m-cresol. Statistically branched samples have been obtained by copolymerizing 8-caprylolactam with bislactams. The degree of branching as well as the branching ability of different bislactams are discussed and compared with the corresponding data for branched polycaprolactams. ZUSAMMENFASSUNG : Lineares Polycapryllactam wurde hergestellt und fraktioniert, und die [q]-w-Beziehung in m-Kresol wurde bestimmt. Statistisch verzweigte Proben wurden durch Copolymerisation von 8-Capryllactam mit Bislactamen erhalten. Der Verzweigungsgrad und die Fahigkeit zur Verzweigung verschiedener Bislactame wird diskutiert und mit den entsprechenden Daten fur verzweigte Polycaprolactame verglichen. * Communication XL: Makromol. Chem., in press.

Molecular Structure of the Complex of Hexano-6-lactam with Magnesium Bromide

“…[10] Magnesium bromide (Aldrich), used without further purification was dried at 20 8C/20 Pa for 24 h. Benzene was distilled and dried over sodium.…”

Reactivity of 6-Hexanelactam Cyclic Oligomers, 1. Acidolysis

“…[12] The cyclic dimer of 6-hexanelactam was isolated [13] from the concentrated aqueous extracts of the polyamide rayon production (CHEMES, a. s., Humenné, Slovak Republic), recrystallized three times from methanol and dried similarly to 6-hexanelactam. Its purity, as determined by HPLC, was higher than 99.9%.…”

Polymerization of lactams, 94. Formation of cyclic oligomers in anionic polymerization of 6-hexanelactam

“…The shift of the cycle-chain equilibrium depends not only on temperature, but also on the structure of the monomer (number of atoms in the ring). In equilibrium polymerization products of the so-called higher lactams, above all 12-dodecanelactam 1,2) or 8-octanelactam 3) , the content of cyclic oligomers is several times higher than that of unreacted monomer. About 70% of the low-molecular extractable fractions of the equilibrium products of 6-hexanelactam polymerization consist of the unreacted lactam, the rest being the cyclic and linear oligomers.…”