Mechanism of alternating inter‐intramolecular propagation. II. General kinetics

Abstract

SynopsisThe general kinetics of alternating inter-intramolecular propagation are presented and discussed. The major factor which determines the microstructure of the polymer, the relative rates of the intramolecular and intermolecular reactions is examined. From the general kinetics methods are proposed for the determination of the ratio of rate conatants for these reactions.[ml]/ [M3] = 1 + (kc/kll)(l/[Ml]o), where [ml] is the concentration of monomer units in the polymer, [M3] is the concentration of uncyclized units, [MI] is a parameter related to monomer concentration, k, is the rate constant for cyclization and k11 the rate constant for linear propagation. Other methods which may give information on the nature of the termination reaction are discussed.

Sonochemical cyclopolymerization of diallylamine in the presence of peroxomonosulfate

“…The observed kinetics in this study were similar to those observed for the polymerization of DA with PDS in the presence of ultrasound;16 this suggests that the mechanistic schemes may be similar. The results of the polymerization dynamics of symmetrical nonconjugated diolefin seem to indicate that whereas the initiation and termination processes are similar to those in monovinyl polymerization,13 it involves a different mechanism for propagation 18. Therefore, we propose a reaction scheme incorporating cyclopolymerization as the propagation step to derive the rate expression (Scheme ).…”

“…It is easy to believe that DA also would be expected to cyclize and give five‐membered cyclized units because the medium was polar and the [M] used here was also low. The formation of stable five‐ or six‐membered rings during cyclization is well known 18, 19. Mostly, DA and the quaternary ammonium salts (diallyldimethyl ammonium chloride) yield cyclopolymers consisting largely of five‐membered rings 21, 22…”

Polymerization of N,N′‐methylenebis(acrylamide) using potassium peroxydiphosphate–thiocarboxylic acid redox systems: A comparison

“…9,10,13,14 In the case of acrylic anhydride polymerization, discussions related to the possibility of five-membered ring formation over a six-membered one in polar media were given. 17,18 Low monomer concentration and polar media favored five-membered ring formation. During MBA polymerization a sevenor eight-membered ring can be expected to form in the propagation step.…”