Control of macromolecular architecture of polyamides by poly-functional agents. 2. Use of oligomerization in polycondensation study |
| |
Authors: | Cuiming Yuan Giuseppe Di Silvestro Franco Speroni Cesare Guaita Haichun Zhang |
| |
Institution: | 1. Università di Milano, Dipartimento di Chimica Organica e Industriale, INSTM Unità di ricerca di Milano, Via Venezian 21, I-20133 Milano, Italy;2. Rhodia Engineering Plastics, Via 1 Maggio, 80, Ceriano Laghetto (MI), Italy |
| |
Abstract: | In the first paper of the series, a statistical model for star-branched polycondenzation of AB type monomers in the presence of a polyfunctional agent RAf was completely developed. The analytical expressions obtained for the number-average (D?P?n?) and weight-average (D?P?w?) degree of polymerization, and the dispersion index (D) for whole polymer species, linear and star macromolecular chains, are now derived as function of the feed and of end-group analysis. Also the important molecular parameter, mole fraction of star-branched polymer, can be evaluated. Some numerical examples are presented. It is illustrated that the molecular weight properties of the linear and star-branched polymers in the mixture of the products, very important factors for the application of this kind of polymeric materials, can be determined starting from the feed and terminal group analysis. Polymerization and oligomerization of 6-aminocaproic acid were carried out in the presence of trimesic (T3) acid and 2,2,6,6-tetra(β-carboxyethyl)cyclohexanone (T4) and EDTA as tri- and terra-functional agents. The molecular weights calculated are in good agreement with those obtained by Size Exclusion Chromatography (SEC), end group analysis and NMR spectra. |
| |
Keywords: | molecular weight distribution polycondensation size exclusion chromatography (SEC) star polymers |
|
|