Cationic Copolymerization of o-Phthalaldehyde and Vinyl Monomers with Various Substituents on the Vinyl Group or in the Pendant: Effects of the Structure and Reactivity of Vinyl Monomers on Copolymerization Behavior

Abstract

Cationic copolymerization of o-phthalaldehyde with various styrene derivatives and vinyl ethers was investigated, particularly focusing on the relationship between the structure and reactivity of vinyl monomers and the copolymerization behavior. In the case of styrene derivatives, the existence of α- or β-substituents (or cyclic structures) on the vinyl group was indispensable for efficient crossover reactions. Styrene derivatives with no substituents on the vinyl group did not undergo copolymerization with OPA. In contrast, various vinyl ethers other than α-substituted vinyl ethers underwent copolymerization with OPA. To realize alternating-like copolymerization, the use of vinyl monomers that have both large steric hindrance and highly reactive β-carbon was effective. In addition, copolymers that are degradable into low-molecular-weight compounds were successfully obtained from styrene derivatives.

Anionic Copolymerization of o-Phthalaldehyde with Epoxides: Facile Access to Degradable Polyacetals and Their Copolymers under Ambient Conditions

“…13,16,24,25 Recently, Aoshima and co-workers carried out at −78 °C the synthesis of various alternating copolymers via cationic copolymerization of OPA with vinyl ethers. 10,26,27 In all cases all the (co)polymerizations have to be carried out at lower temperature than T c (−36 °C) 9 of OPA irrespective of the comonomers used.…”

“…They have to be end-capped after polymerization to avoid depolymerization under ambient conditions. − Molar masses as high as 200 kg/mol were obtained . Some works report the modification of the thermal, mechanical, and chemical properties of PPA through their copolymerization with substituted benzaldyhyde, glyoxylate, − and phthalaldehyde derivative monomers; ,,− the synthesis of block copolymers through the macroinitiator approach has also been considered. ,,, Recently, Aoshima and co-workers carried out at −78 °C the synthesis of various alternating copolymers via cationic copolymerization of OPA with vinyl ethers. ,, In all cases all the (co)­polymerizations have to be carried out at lower temperature than T c (−36 °C) of OPA irrespective of the comonomers used.…”

Alternating-like Cationic Copolymerization of Styrene Derivatives and Benzaldehyde: Precise Synthesis of Selectively Degradable Copoly(styrenes)

“…α- or β-substituted St derivatives , were subjected to copolymerization with BzA because the substituents on the vinyl group were expected to reduce the frequency of the homopropagation and instead promote the crossover reactions with BzA. Indeed, various α- or β-substituted St derivatives were demonstrated to undergo frequent crossover reactions in cationic copolymerization with o -phthalaldehyde in our recent study . However, all the α- or β-substituted St derivatives employed in this study were ineffective for copolymerization (Table and Figures S12–S16) under these conditions.…”

“…Indeed, various αor β-substituted St derivatives were demonstrated to undergo frequent crossover reactions in cationic copolymerization with o-phthalaldehyde in our recent study. 29 However, all the αor β-substituted St derivatives employed in this study were ineffective for copolymerization (Table 3 and Figures S12− S16) under these conditions. In the case of α-methylstyrene (αMeSt), an αMeSt homopolymer and a cyclic trimer consisting of one αMeSt and two BzA units were obtained (entry 1 in Table 3).…”

Asymmetric Ion-Pairing in Stereoselective Vinyl Polymerization

“…AIP catalysis has been most successful for cationic polymerization in terms of its application to a variety of monomer substrates. Despite this success, there are limited reports of the stereoselective polymerization of 1,2-disubstituted alkenes, for example, propenyl ethers, to generate a ditactic polymer. , Given these polymers typically have high glass transition temperatures and are proposed as more sustainable alternatives to current glassy thermoplastics, control of their stereochemistry would enable a larger diversity of properties from these readily available and underexplored monomers. − A complementary goal is a continued pursuit of methods that provide stereoselective polymerization under living conditions, which would provide access to stereoblock materials or complex polymer architectures that could alter crystallization and thermomechanical and optical properties.…”