Reassessment of Free-Radical Polymerization Mechanism of Allyl Acetate Based on End-Group Determination of Resulting Oligomers by MALDI-TOF-MS Spectrometry

Predominant methyl radical initiation preceded by β-scission of alkoxy radicals in allyl polymerization with organic peroxide initiators at elevated temperatures

“…As discussed in our preceding article, 14 the intramolecular (backbiting) hydrogen abstraction that forms mid-chain radicals, which subsequently undergo b-scission of the main chain, resulting in poly(ABz) with a terminal ¼CH 2 group, and a new radical C 6 H 5 COOCH 2 CH 2 with high reinitiation reactivity, leads to the appearance of G-series peaks: Figure 6 MALDI-TOF-MS spectrum of oligomeric poly(ABz) (M n ¼4120) obtained at a conversion of 7.2% in the bulk polymerization of ABz using 0.1 mol l À1 DBPO for 30 min at 130 1C.…”

“…14,17 The allyl polymer (2.0 mg ml À1 ), DHBA matrix (20 mg ml À1 ) and NaI cationizing agent (1.0 mg ml À1 ) were dissolved in THF. Thereafter, 0.5 ml from each of these solutions was deposited on a stainless sample target by the overlayer method as follows: first deposition, matrix solution; second, cationizing agent solution and third, polymer solution.…”

“…[5][6][7] The wellknown allyl polymerization mechanism [8][9][10][11][12][13] is based on kinetic data alone, without structural identification. In our preceding study, 14 allyl acetate (AAc), a typical allyl monomer, was polymerized radically, and the resulting oligomeric poly(AAc)s were characterized using matrixassisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) to reassess the AAc polymerization mechanism proposed by Litt and Eirich; 13 their mechanism was based on results reported in the period . We propose a renewal of the wellknown reaction scheme for the free-radical polymerization of AAc.…”

Molecular Design of Core‐Shell Type Allylic Nanoparticles Based on Crosslinking Multiallyl/Multivinyl Copolymerizations

“…[4] In diallyl polymerization only the oligomeric primary polymer chain is formed and, moreover, its length is advantageously kept constant because a well-known degradative monomer chain transfer [11] or allylic hydrogen abstraction of growing polymer radical is an essential chain-forming reaction in allyl polymerization. [13] This situation is completely different from a common crosslinking multivinyl polymerization accompanied by the gel effect [14] which is induced as a result of reduced bimolecular termination, resulting in an enlargement of primary polymer chain length, eventually leading to microgel formation. [9,[15][16][17][18][19][20][21][22] Thus, the most significant difference between crosslinking multiallyl and multivinyl polymerization mechanisms is in the termination reaction.…”

Photo-initiated copolymerization of allyl and vinyl ethers with dialkyl fumarates: A mechanistic investigation by ESI mass spectrometry

“…In addition, b-scission and transfer reactions are frequently reported to take place in the absence [26] or in the presence of a chain transfer agent [27], to the solvent, to the monomer [28] or to the polymer [29]. MALDI-TOF-MS has been used not only to investigate propagation [30], but for evidencing irreversible termination in controlled free-radical polymerization [31]. The contribution of side reactions, such as intermolecular transesterification [32] or back-biting, which influence the microstructure of obtained copolymers, has been evaluated by both MS methods [33].…”