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

Abstract

ABSTRACT:The kinetics of aqueous polymerization of the symmetrical nonconjugated divinyl monomer N,N-methylenebis(acrylamide) (MBA), was studied at 35ЊC and at constant ionic strength under nitrogen atmosphere involving potassium peroxydiphosphate (PDP) as oxidant with three different activators thiolactic acid (TLA), thiomalic acid (TMA), and thioglycollic acid (TGA). The rate of polymerization, R P , and rate of disappearance of peroxydiphosphate, 0R PDP have been followed while polymerization was initiated separately by the PDP-TLA/PDP-TMA/PDP-TGA redox systems. R P for the above three systems showed first-order dependences on both [ [activators] were observed with respect to 0R PDP in the above three systems. A reaction mechanism which involves complex formation between PDP and thiocarboxylic acid, propagation through intramolecularintermolecular reactions, degradative chain transfer reaction of the growing radical with PDP, and linear termination by the interaction of the chain radical with primary radical was proposed. The kinetic parameters for the three polymerization systems were calculated and compared.

Chemical Oxidative Polymerization and in situ Spectroelectrochemical Studies of a Sulfonated Aniline Derivative by UV−Visible Spectroscopy

“…Polymerization of DPASA is proposed to proceed through the formation of a radical cation of DPASA by the oxidation of DPASA with PDS (reactions (1) and (1a)). PDS was reported to initiate the polymerization of aniline/aniline derivatives by these type of reactions. − The DPASACR is further transformed into dimeric species accompanied by deprotonation . An electrophilic attack of dimer with DPASACR results in a trimeric cation radical, which upon subsequent deprotonation generates a neutral trimer.…”

“…PDS was reported to initiate the polymerization of aniline/aniline derivatives by these type of reactions. [33][34][35][36][37] The DPASACR is further transformed into dimeric species accompanied by deprotonation. 21 An electrophilic attack of dimer with DPASACR results in a trimeric cation radical, which upon subsequent deprotonation generates a neutral trimer.…”

“…21,25,32 The presence of an intercept in the plot has been explained by the autoacceleration effect caused by the heterogeneity of the medium. Gopalan and co-workers [33][34][35][36][37] explained the autocatalytic effect under the heterogeneous conditions where the polymer was precipitated. Through several studies [33][34][35][36][37] it was concluded that the heterogeneity of the medium resulted in autoacceleration in chemical oxidative polymerization of ANI and ANI derivatives in the presence of added fibers.…”

“…Gopalan and co-workers [33][34][35][36][37] explained the autocatalytic effect under the heterogeneous conditions where the polymer was precipitated. Through several studies [33][34][35][36][37] it was concluded that the heterogeneity of the medium resulted in autoacceleration in chemical oxidative polymerization of ANI and ANI derivatives in the presence of added fibers. Hence, the observed linear nature of the plot of R p vs [DPASA] (Figure 4, plot A), which was found to pass through the origin, indicates that the autoacceleration effect is not dominant in DPASA polymerization.…”

“…The above two equations suit in explaining the kinetics of PANI formation when autoacceleration by the formed polymer and surface effects on polymerization were dominant. From our research group, results have been reported on the establishment of the kinetic equation for the polymerization of ANI and o-toluidine [33][34][35][36][37] in the presence of added substrates, while the polymer was precipitating during the course of polymerization.…”