Jaroslav Králíček

On distribution of molecular weight in anionic polymerizates of caprolactam

Abstract Measurement has been made of the dependence of the molecular weight distribution on the ratio of the catalytic system components and on the polymerization time for polycaprolactam obtained by anionic polymerization. A bimodal character of the curves was observed for products made using molar ratios of activator ( N -benzoylcaprolactam) to initiator (sodium dihydro-bis(methoxyethoxy)aluminate) of 1:1 and 1:3, when the polymerization times were less than 1 hr. This course is explained by the influence of fast side-reactions, mainly condensations. For a ratio of 3:1 of the components of the catalytic system, smooth integral distribution curves are obtained, accounting for a very fast decrease in the strong base concentration in the initial stages of the polymerization.

Polymerization of lactams

SummaryThe anionic polymerization of 2-pyrrolidone is markedly affected by 1-(1-pyrrolin-2-yl)-2-pyrrolidone which probably influences the propagation reaction. A kinetic analysis of the polymerization process demonstrates its distinct similarity with non-activated polymerization. The polymers thus obtained possess a satisfactory thermal stability.

Effects of the reaction conditions on the anionic polymerization of 2-pyrrolidone

Abstract The effects of temperature and initiator and activator concentrations on the anionic polymerization of 2-pyrrolidone were studied. Potassium tert, butanolate and γ-butyrolactone served as initiator and activator respectively. The polymer yield and intrinsic viscosity of the polymer were employed as criteria for evaluating the polymerization process. The orthogonal central composition planning of the experiment was used as an approach to studying the problem; the results were processed to yield explicit mathematical equations by using a digital computer. In the region measured, the polymer yield as well as the intrinsic viscosity were found to increase with increasing temperature. initiator concentration and polymerization time.

Polymerization of lactams: 70. Anionic polymerization of 2-pyrrolidone accelerated with N-iminolactams

SummaryA pronounced acceleration of the anionic polymerization of 2-pyrrolidone (PD) occurs with the following N-iminolactams: 1-(1-pyrrolin-2-yl)-2-pyrrolidone (PDPD), 1-(1-azacyclohept-1-en-2-yl)-2-pyrrolidone (CLPD), and 1-(1-azacyclohept-1--en-2-yl)-1-aza-2-oxocycloheptane (CLCL). This acceleration effect on the anionic polymerization of PD initiated with 2-oxo-1-pyrrolidinylpotassium decreases in the sequence CLPD> PDPD > CLCL. The possible role of N-iminolactams in the system is discussed.