Radical polymerization of diallylamine compounds: From quantum chemical modeling to controllable synthesis of high‐molecular‐weight polymers

Abstract

ABSTRACT:We investigated the possibility to obtain high-molecular-weight (HMW) polymers from the monomers of the diallylamine (DAA) series using quantum chemical and experimental methods. Such monomers are known to polymerize into oligomeric products due to the reaction of the degradative chain transfer to the monomer. We studied potential energy profiles of the chain propagation and competing chain transfer reactions, viz., the free radical double bond addition and ␣-hydrogen radical abstraction, respectively, for a number of polymerization processes. Calculations were carried in the framework of the polarized continuum solvent model utilizing the procedure based on the semiempirical MNDO-PM3 background. It was found that the necessary condition for decreasing competitiveness of the chain transfer to the monomer is the availability of monomer molecules in only protonated form in the polymerizing system. Using these results, we developed the strategy for obtaining HMW polymers based on said monomers. We synthesized a monomer system (the equimolar salt of N,N-diallyl-N-methylamine and trifluoroacetic acid) that fully corresponds to such requirements. Novel HMW polymers were then synthesized by radical polymerization of this salt at soft conditions. We established that chain termination is controlled by the bimolecular mechanism. We showed that the degradative chain transfer transforms into the effective chain transfer. The mechanisms of the observed phenomena are discussed.

Secondary and Tertiary Polydiallylammonium Salts: Novel Polymers with High Antimicrobial Activity

“…In relation with this, of special interest is the high biocidal efficiency of novel water-soluble nonquaternary polymers of poly(diallylammonium) salts series (PDAAs) discovered by the authors, namely, the secondary poly(diallylammonium trifluoroacetate) (PDAATFA) and tertiary poly(diallylmethylammonium trifluoroacetate) (PDAMATFA), which have been synthesized recently. , The antimicrobial activity of secondary and tertiary PDAAs had not been reported before. Due to difficulties in preparation of polymers from monomers of the diallylamine (DAA) series in nonquaternary form, which are related to degradative chain transfer to monomer and kinetic chain termination, up to recently it was not possible to obtain secondary and tertiary PDAAs with a sufficiently high molecular mass. − We have proposed an approach that is essentially based on the creation in the polymerizing medium of a dominant amount of monomers of the DAA series in protonated form, owing to which the competitive ability of the chain transfer to monomer reaction diminishes and the degradative chain transfer transforms into the effective one . In accordance with this approach, the methods has been employed for the synthesis of novel monomer systems, namely trifluoroacetic salts of the monomers of DAA series, and the cationic polyelectrolytes on their bases.…”

Synthesis and modeling of new phosphorus‐containing acrylates

“…Davis and coworkers26, 27 used methyl radical addition to model the propagation reaction to probe the Q–e (activity charge) scheme. The methyl radical was chosen as a model for the propagating radical by Timofeeva et al,28 who carried out quantum chemical modeling of the radical polymerization of diallylamine compounds and achieved controllable syntheses of high‐molecular‐weight polymers.…”

Modeling the free radical polymerization of acrylates

“…We studied the potential energy profiles and the kinetics of chain propagation and the competing chain transfer reactions by considering the addition of the free radical to the double bond and the α‐hydrogen abstraction as shown in Figure 4. This strategy has already been used by Timofeeva et al 30, who carried out quantum chemical modeling of the radical polymerization of diallylamine compounds and had achieved controllable synthesis of high molecular weight polymers.…”