1:2‐sequence‐regulated radical copolymerization of naturally occurring terpenes with maleimide derivatives in fluorinated alcohol

Abstract

Naturally occurring bulky terpenes, such as (þ)-and (-)-limonene and (-)-b-pinene, were quantitatively copolymerized with maleimide (MI) derivatives (i.e., phenyl-, cyclohexyl-, ethyl-, and unsubstituted-MI) in PhC(CF 3 ) 2 OH solvent via selective 1:2alternating propagation governed by the penultimate effect, which resulted in 1:2-sequence regulated polymers with relatively high glass transition temperatures and optical activities. Similar petroleum-derived bulky olefins possessing cyclohexenyl, cyclohexyl, or additional a-methyl substituents were copolymerized with phenylmaleimide via preferential 1:2-alternating propagation with a slightly lower selectivity. A further decrease in the bulkiness of nonpolar olefins increased the 1:1-alternating sequence. The copolymerization of limonene and acrylonitrile also proceeded approximately via 1:1-alternating propagation, in which the penultimate effect was less observable. Furthermore, when methylene chloride was used instead of fluorinated alcohol for the copolymerization of limonene and phenylmaleimide, the length of the sequence of MI units increased. Thus, in addition to the characteristic MI skeleton, the bulky and rather specific structure of either limonene or b-pinene induces 1:2-selective propagation via the penultimate effect, whereas the fluoroalcohol diminishes the homopropagation of MI via a hydrogen bonding interaction with the MI unit. RAFT copolymerization of limonene and various MI derivatives in PhC(CF 3 ) 2 OH successfully proceeded to give the end-to-end 1:2-sequence-regulated copolymer with a selective initiating sequence and predominant capping sequence using an appropriate RAFT agent.

Sequence-Controlled Radical Copolymerization of N-Substituted Maleimides with Olefins and Polyisobutene Macromonomers To Fabricate Thermally Stable and Transparent Maleimide Copolymers with Tunable Glass Transition Temperatures and Viscoelastic Properties

“…Recently, Kamigaito et al reported the 1/r 12 value of 0.33 in the fluorinated cumyl alcohol, PhC(CF 3 ) 2 OH, for the same copolymerization system of O3 (M 1 )−PhMI (M 2 ). 55 The 1/r 12 value observed in this study was higher than the reported one, being ascribed to the solvent effects. 58,62 It was reported that the fluoroalcohol diminished the homopropagation of PhMI via a hydrogen bonding interaction with the carbonyl Table 1).…”

Synthesis, characterization and properties of a bio-based elastomer: polymyrcene

“…4 On the other hand, terpenes or terpenoids refer to one of the largest families of naturally occurring compounds and are secondary metabolites synthesized mainly by plants, particularly conifers. 8 To make use of the chemical functionalities (unsaturation, functional groups) present in terpene molecules, various chemical strategies and a wide range of polymerisation techniques [9][10][11][12][13][14][15][16][17][18][19] had been studied. Thus, due to their abundance in nature, there has been great interest in producing polymers with terpenes as either functional entities or as the main constituent.…”

Synthesis and Characterization of Thermoresistant Maleimide Copolymers and their Crosslinked Polymers

“…[17,18] The sophisticated AAB-type sequence structures were produced during the copolymerization under penultimate unit control (Scheme 1). [19][20][21][22] It was previously reported that the maleimide copolymers including an allyl group in the side chain were fabricated by the combination of olefin moieties with different reactivity. [23] This was unique method for the design of a new thermosetting system including radical reaction processes for polymerization and postpolymerization reactions.…”