STRUCTURE OF POLY-OMEGA-DODECALACTAM OBTAINED IN BULK BY AN ANIONIC MECHANISM

The nascent structure of poly-omega-dodecalactam, nylon-12 (PA-12), ob tained during bulk polymerization of omega-dodecalactam by an anionic mechanism has been investigated. The omega-dodecalactam polymerization and PA-12 crystallization proceed in a successive manner. The influen ce of the type and concentration of the initiators and activators or m odifiers on polymerization rate, molecular weight of the obtained PA-1 2, crystallinity degree, crystal size, alteration of melting temperatu re and enthalpy, and crystal lattice parameters has been studied. The structural changes in PA-12 depending on polymerization conditions are studied by means of infrared spectroscopy, differential scanning calo rimetry, wide-angle X-ray scattering and polarized light optical micro scopy. It is established that the type of initiator and activator or m odifier as well as their concentration exert a substantial effect on t he formation of the supermolecular structure of the obtained modified PA-12. (C) 1997 Elsevier Science Ltd.