Controlled polymerization of acrylic acid under ⁶⁰Co irradiation in the presence of dibenzyl trithiocarbonate

Abstract

The polymerization of acrylic acid (AA) was performed under 60 Co irradiation in the presence of dibenzyl trithiocarbonate at room temperature, and welldefined poly(acrylic acid) (PAA) with a low polydispersity index was successfully prepared. The gel permeation chromatographic and 1 H NMR data showed that this polymerization displays living free-radical polymerization characteristics: a narrow molecular weight distribution (M w /M n ϭ 1.07-1.22), controlled molecular weight, and constant chain-radical concentration during the polymerization. Using PAAOSO C(AS)OSOPAA as an initiator, the extension reaction of PAA with fresh AA was carried out under 60 Co irradiation, and the results indicated that this extension polymerization displayed controlled polymerization behavior.

Xanthate‐Mediated Controlled/Living Free‐Radical Polymerization under 60Co γ‐Ray Irradiation: Structure Effect of O‐Group

“…In addition, we noted that the polymerization of St with X2 was a controlled process though it was very slow ( Table 1, entries [12][13], and the uncontrolled polymerization of MMA occurred under g-ray irradiation (Table 1, entries [14][15]. Similar results have been discussed in our previous work.…”

“…[1] Some prominent techniques have developed, such as living free radical nitroxide-mediated polymerization (NMP), [2][3][4] atom transfer radical polymerization (ATRP) [5][6][7][8] and the reversible addition-fragmentation chain transfer (RAFT) [9,10] process. More recently Bai et al found that controlled/living free radical polymerizations of vinyl monomers can be performed under 60 Co g-ray irradiation in the presence of dibenzyl trithiocarbonate [11][12][13] and dithiobenzoic acid, [14] though the g-ray irradiated polymerization is generally very difficult to control. Subsequently, Quinn et al reported the living free radical polymerizations of styrene [15] and methyl methacrylate, [16] and the graft polymerization of styrene onto a polypropylene solid phase [17,18] under g-ray irradiation with cumyl phenyldithioacetate and cumyl dithiobenzoate.…”

RAFT Polymerization of N‐Isopropylacrylamide and Acrylic Acid under γ‐Irradiation in Aqueous Media

“…Thus, in the past few years, g-irradiation has been increasingly used in the context of the RAFT process to obtain well-defined (living) polymers. [22][23][24][25] The mechanism of the RAFT process has been detailed elsewhere and the complexities of its mechanism will not be reiterated here. [26] While the present study employs radiolysis to generate the initiating radicals, in principle, there is no difference between g-initiated and thermally initiated polymerization.…”

Direct Synthesis of Controlled Poly(styrene‐co‐acrylic acid)s of Various Compositions by Nitroxide‐Mediated Random Copolymerization

“…[24] The controlled homopolymerization of acrylic acid was also performed at room temperature in the presence of dibenzyltrithiocarbonate, under 60 Co irradiation. [25] The MADIX process (macromolecular design via the interchange of xanthates) was successfully used in aqueous solution to prepare a welldefined poly(acrylic acid) homopolymer and hydrophilic copolymers based on acrylamide and acrylic acid. [26] A few other examples of copolymers bearing a poly(acrylic acid) sequence and synthesized using the RAFT technique can be found in the literature.…”