Distribution of the number of arms of (PSt)f−n-star-(PIs)n hetero-star block copolymers prepared via anionic living polymerization of macromonomers

Se, Kazunori; Yoshizawa, Akira

doi:10.1016/j.polymer.2009.09.041

Cited by 2 publications

(3 citation statements)

References 17 publications

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“…The α‐end‐styryl‐terminated PHIC macromonomer (St‐PHIC‐NH) was radically polymerized by AIBN in Bz to produce a polymacromonomer, (PHIC‐NH) f , where f is the number of side chains 31, 32. As shown in Table 3, the M w LALLS value of the (PHIC‐NH) 3.43 seems to be smaller than those of common polymacromonomers such as (PSt) f and (PHIC) f reported by other groups.…”

Section: Resultsmentioning

confidence: 99%

Selective complete decomposition of poly(n‐hexylisocyanate) and its use in a new molecular design method

Iwata

2011

J. Polym. Sci. A Polym. Chem.

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Poly(n‐hexylisocyanate) (PHIC‐NH) as a rod‐like polymer having a NH group at one end of the polymer chain was found to instantly (less than a few seconds) be completely decomposed by CH3O−Na+ in tetrahydrofuran/CH3OH under a mild experimental condition ([CH3O−Na+] < 1 mol L−1 at room temperature).The mechanism of the decomposition for the PHIC‐NH consists of two steps: the first is abstraction of the proton for PHIC‐NH by Na+ with a slow reaction rate, and the second is the consequent depolymerization of PHIC‐N− based on the equilibrium polymerization with a rapid depolymerization rate. The decomposition rate constants (kd) depend on Mw of PHIC‐NH, namely kd ∼ Mw−1.0. The decomposition of the PHIC‐NR having an end‐capped NR group was completely depressed. Using an “all or nothing” mechanism for the decomposition, the (PHIC)3.43 comb‐shaped polymer and polystyrene (PSt)‐graft‐(PHIC‐NH)4.28 graft copolymer were, respectively, decomposed to produce (PHIC‐NH)3.43–1.03 and PSt‐graft‐(PHIC‐NH)4.28–0 in a series with different numbers of PHIC‐NH combs and PHIC‐NH grafts by regulating the amount of CH3O−Na+ and the decomposition time. Molecular structure of (PHIC‐NH)3.43–1.03 and PSt‐graft‐(PHIC‐NH)4.28–0 was discussed from a viewpoint of PSt‐reduced chain dimension per molar mass. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011

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Section: Resultsmentioning

confidence: 99%

Selective complete decomposition of poly(n‐hexylisocyanate) and its use in a new molecular design method

Iwata

2011

J. Polym. Sci. A Polym. Chem.

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“…For the GPC measurements, two high-resolution columns (G2500H, G3000H, G400H and GMH-M, 7.8 mm x 60 cm; Tosoh Co.) were connected in a series. Special analysis was required to determine M n and M w values of the (PMSt) m polymacromonomers using GPC-LALLS [15,27].…”

Section: Molecular Characterizationmentioning

confidence: 99%

“…We have proposed another technique of purifying the styrenic macromonomers that is similar to that of purifying common monomers [14]. That is, the THF solution of the styrenic macromonomer and a cross-linked polystyrene particle containing benzophenone sodium (R-C 6 H 5 -CO -C 6 H 5 Na + ) as a purging reagent was stirred for 48 h and the purified macromonomer was then separated from the suspension by a glass filter under high vacuum [2,14,15]. This paper provides a different method of purifying and polymerizing the macromonomers [16][17][18] by using a concept of anionic living-equilibrium polymerization (ALEP) [19][20][21].…”

Section: Introductionmentioning

confidence: 99%

Kinetic and thermodynamic characteristics of anionic living-equilibrium polymerization for (p-Isopropenylphenethyl)poly(α-methylstyrene) macromonomer

Se¹,

Suzuki²

2010

Polymer

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The anionic living-equilibrium polymerization (ALEP) of (p-isopropenylphenethyl)poly(α-methylstyrene) macromonomer (PMStM) was studied: PMStM was simultaneously purified and initiated above a ceiling temperature (T c) and then propagated below T c. Three PMStMs (M n =1.77x10 3 , 3.65x10 3 , and 5.36x10 3) were prepared by the coupling of poly(α-methylstyryllithium) with p-isopropenylphenethyl chloride, and were polymerized to produce polymacromonomers, (PMSt) m (m = 9.5, 4.1, and 3.5) by n-BuLi in d 8-THF at temperatures below-10°C under high vacuum via ALEP. From kinetic studies using an 1 H NMR technique, the propagation rate constant (0.240, 0.110, and 0.079 l mol-1 s-1) at-78°C was found to be proportional to a reciprocal of M n of PMStM, and its M n dependence was discussed based on a simple diffusion-controlled theory. The thermodynamic characteristics of ΔH MSt (-7.48,-6.73, and-3.82 kJ mol-1) and ΔS MSt (-26.8,-24.1, and-13.7 J mol-1 K-1) were determined from a kinetic analysis, and their M n dependence was also discussed. The T C values for the three PMStM, including α-methylstyrene, were found to be the same (6.0°C).

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Distribution of the number of arms of (PSt)f−n-star-(PIs)n hetero-star block copolymers prepared via anionic living polymerization of macromonomers

Cited by 2 publications

References 17 publications

Selective complete decomposition of poly(n‐hexylisocyanate) and its use in a new molecular design method

Selective complete decomposition of poly(n‐hexylisocyanate) and its use in a new molecular design method

Kinetic and thermodynamic characteristics of anionic living-equilibrium polymerization for (p-Isopropenylphenethyl)poly(α-methylstyrene) macromonomer

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