Takuya Isono

International audience

The AB2- and AB3-type miktoarm star copolymers consisting of maltoheptaose (MH, as A block) and poly(ε-caprolactone) (PCL, as B block), namely MH-b-(PCL)2 and MH-b-(PCL)3, were synthesized, and their nano-organization was characterized. The syntheses of MH-b-(PCL)2 and MH-b-(PCL)3 were carried out through two reaction steps: (1) preparation of linear and three-branched PCLs bearing an azido group on the chain center (N3-(PCL)2 and N3-(PCL)3) by the diphenyl phosphate-catalyzed ring-opening polym

This paper describes the synthesis of systematic sets of figure-eight- and tadpole-shaped amphiphilic block copolyethers (BCPs) consisting of poly(decyl glycidyl ether) and poly[2-(2-(2-methoxyethoxy)ethoxy)ethyl glycidyl ether], together with the corresponding cyclic counterparts, via combination of the t-Bu-P4-catalyzed ring-opening polymerization (ROP) and click cyclization. The clickable linear BCP precursors, with precisely controlled azido and ethynyl group placements as well as a fixed mo

Self-switchable polymerization is an attractive strategy for precisely controlling the microstructures and monomer sequences of polymers. To date, catalysts for the polymerization are generally limited to metal complex catalysts and some organocatalysts. In this article, we report that simple, inexpensive, and environmentally benign alkali metal carboxylate catalysts smartly switch between the ring-opening alternating copolymerization of epoxides with cyclic anhydrides and the ring-opening polym

Synchronously and thoroughly adjusting the chemical structure difference between two blocks of the diblock copolymer is very useful for designing materials but difficult to achieve via self-switchable alternating copolymerization. Here, we report self-switchable alternating copolymerization from a mixture of two different cyclic anhydrides, epoxides, and oxetanes, where a simple alkali metal carboxylate catalyst switches between ring-opening alternating copolymerization (ROCOP) of cyclic anhydri

The synthesis of well-defined four-armed star-shaped poly(butylene oxide) and figure-eight-shaped poly(butylene oxide)s (s-PBO and 8-PBO, respectively) with predicted molecular weights and narrow molecular weight distributions (Mw/Mns) was achieved by the t-Bu-P4-catalyzed ring-opening polymerization (ROP) of butylene oxide (BO). The t-Bu-P4-catalyzed ROP of BO using 1,2,4,5-benzenetetramethanol as the initiator produced s-PBOs having number-average molecular weights (Mn,NMRs) ranging from ca. 4

Three different self-assembled nanostructures, i.e., lamellar (Lam), hexagonally close-packed cylinder (Hex), and body-centered cubic (BCC), have been obtained from ABA triblock (MH-b-PCL-b-MH) and A2B star-branched copolymers ((MH)2-b-PCL) consisting of maltoheptaose (MH, as the A block) and polycaprolactone (PCL, as the B block). MH-b-PCL-b-MH and (MH)2-b-PCL were synthesized by the click reaction of the α,ω-diazido and α,α-diazido end-functionalized PCLs with N-maltoheptaosyl-3-acetamido-1-pr

Random and block copolymerizations of poly(l-lactide) (PLLA) and poly(d-lactide) (PDLA) macromonomers having an exo-norbornene group at the α- or ω-chain end (D/L ratio = 1/1, Mn = ca. 5000 g mol–1) were performed via ring-opening metathesis polymerization to produce the brush random and block copolymers consisting of parallel or antiparallel aligned PLLA and PDLA side chains on a poly(norbornene) backbone. The molecular weight and polydispersity index of the brush copolymers were in the range o

The combination of t-Bu-P4 and alcohol was found to be an excellent catalytic system for the controlled/living ring-opening polymerization (ROP) of N,N-disubstituted glycidylamine derivatives, such as N,N-dibenzylglycidylamine (DBGA), N-benzyl-N-methylglycidylamine, N-glycidylmorpholine, and N,N-bis(2-methoxyethyl)glycidylamine, to give well-defined polyethers having various pendant tertiary amino groups with predictable molecular weights and narrow molecular weight distributions (typically Mw/M

Nanofabrication based on block copolymer self-assembly is one of the most promising methods for producing nanopatterns with a sub-10 nm feature size. Although polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA) has been widely studied as a suitable template for nanofabrication, the insufficient incompatibility between the PS and PMMA blocks makes it difficult to achieve a microphase separation with the domain spacing of less than ca. 20 nm. We now present a simple and efficient method for th

Highly regioselective ring-opening polymerization of optically active methylglycolides was achived using P₂-<italic>t</italic>-Bu/alcohol system to produce alternating copolymer of lactic acid and glycolic acid.

A comprehensive study of the synthesis and LCST-type thermoresponsive properties of poly(glycidyl ether) homopolymers and their copolymers is described.

A novel synthesis of multicyclic polymers that feature ultradense arrays of cyclic polymer units has been developed by exploiting the cyclopolymerization of α,ω-norbornenyl end-functionalized macromonomers mediated by the Grubbs third-generation catalyst (G3). Owing to the living polymerization nature, the number of cyclic repeating units in these multicyclic polymers was controlled to be between 1 and approximately 70 by varying the initial macromonomer-to-G3 ratio. The ring size was also tuned

Poly(hydroxyalkanoate)s (PHAs) have gained significant attention because they readily biodegrade even under environmental conditions; however, expanding the applications of these polymers to a number of fields is hindered by their brittle nature. Blending with a soft biodegradable polymer, such as poly(ε-caprolactone) (PCL), is currently the best solution for improving the toughness of a PHA material without sacrificing biodegradability; consequently, the development of biodegradable compatibili

This paper describes the systematic investigation into the aqueous self-assembly of a series of block copolymers (BCPs) consisting of maltoheptaose (MH; as the A block) and poly(ε-caprolactone) (PCL; as the B block), i.e., linear AB-type diblock copolymers with varied PCL molecular weights (MH-b-PCL(2.5k,3.3k,5k,10k)), ABy-type (y = 2, MH-b-(PCL5k)2; y = 3, MH-b-(PCL3.3k)3), A2B2-type ((MH)2-b-(PCL5k)2), and AxB-type miktoarm star polymers (x = 2, (MH)2-b-PCL10k; x = 3, (MH)3-b-PCL10k), which ha