Preparation of α-, ω-End-Functionalized Poly(n-hexyl isocyanate) Heterotelechelics

Lien, Le Thi Ngoc; Kikuchi, Moriya; Narumi, Atsushi; Nagai, Katsutoshi; Kawaguchi, Seigou

doi:10.1295/polymj.pj2008155

Cited by 13 publications

(18 citation statements)

References 23 publications

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“…After less than a few minutes of the polymerization, not only was the (PHIC‐NH) n not prepared but also all the St‐PHIC‐NH macromonomer was completely decomposed. This complete decomposition of PHIC‐NH has also been qualitatively reported based on initial studies of preparing poly(isocyanate) derivatives by Shashoua et al15 and by Iwakura et al16 In recent years, the chemical and thermal stabilization of poly(isocyanate) derivatives has also been studied by Hatada and coworkers17 and by Kawaguchi and coworkers 18. They have discussed the decomposition mechanism for the poly(isocyanate) derivatives and have tried to end‐cap them so as to make them stable when coming into contact with basic chemicals and heat.…”

Section: Introductionsupporting

confidence: 71%

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: Introductionsupporting

confidence: 71%

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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“…The low yield is most likely due to a low reprecipitation efficiency into methanol 22 and/or that depolymerization by back-biting occurs during termination. 27 Disagreement between [HIC] o / [Ini] o and n(NMR) is seen and is caused by low initiator efficiencies and/or depolymerization during termination. Of note on this table, however, is the fact that the values of M n determined from the 1 H NMR peak intensities based on anmethacrylate terminal group are almost identical to the number averaged molecular weight (M n ) determined by SEC calibrated with a series of PHICs, except for MA-EO 8 -HIC-n-Ac with a flexible octa(oxyethylene) chain.…”

Section: Resultsmentioning

confidence: 99%

“…The details have been described in previous papers. 22,27 The reaction was carried out using a three-necked 50 mL flask equipped with a tube containing dry triethylamine to trap HCl gas. In a dry box, to a solution of CpTiCl 3 (1.00 g, 4.56 mmol) in 5 mL dry THF, a solution of !-hydroxy-oligo(oxyethylene) methacrylate (MA-EO m -H) (m ¼ 1, 2, 4.5, 8) (4.56 mmol) in dry THF was slowly added for 30 min.…”

Section: Synthesis Of Titaniummentioning

confidence: 99%

“…The polymerization of HIC was carried out in a drybox; details of the procedure are described in previous papers. 21,22,27 In brief, MA-EO m -CpTiCl 2 and dichloromethane were added to a 20 mL flask fitted with a magnetic stir bar. After the initiator was completely dissolved, a desired amount of HIC was added, the flask was sealed off and taken out of the dry box.…”

Section: Synthesis Of Titaniummentioning

confidence: 99%

“…After the polymerization, the solution containing of a large excess amount of acetic anhydride as a terminator and a BF 3 OEt 2 as a catalyst was added to the solid reaction mixture. 27 The solid body was pulverized in the reaction mixture to disperse it. The dispersion was vigorously stirred for 24 h at room temperature.…”

Section: Synthesis Of Titaniummentioning

confidence: 99%

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Synthesis of Oligo(oxyethylene) Methacrylate-ended Poly(n-hexyl isocyanate) Rodlike Macromonomers and Their Radical Copolymerization Behavior with Methyl Methacrylate

Lien

Kikuchi

Narumi

et al. 2008

Polym J

Self Cite

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A series of novel poly(n-hexyl isocyanate) (PHIC) rodlike macromonomers having an -methacryloyloxyoligo(oxyethylene) group and an !-acetyl group (MA-EO m -HIC-n-Ac, where m and n are the degrees of polymerization of oxyethylene (EO) and HIC, respectively) have been prepared. They were prepared by living coordination polymerization of HIC using corresponding titanium(IV) alkoxide complexes as an initiator in CH 2 Cl 2 at room temperature, followed by termination with acetic anhydride as a terminator in the presence of BF 3 OEt 2 as a Lewis acid. The radical copolymerization behavior of MA-EO m -HIC-n-Ac (M 2 ) with methyl methacrylate (MMA) (M 1 ) in benzene at 60 C has thoroughly been investigated in order to evaluate an effect of a flexible oligo(oxyethylene) spacer (m) on the copolymerizability. The apparent reactivities (1=r 1 ) of MA-EO m -HIC-n-Ac are lower than for MMA (1/r 1 is ca. 0.52) and decrease slightly with increasing m. The copolymerizability of MA-EO m -HIC-n-Ac was compared with that of -4-vinylbenzyoxy-ended PHIC macromonomers (VB-HIC-n-H). The decrease in the copolymerizability of the methacrylate-ended PHIC macromonomers is most likely due to the incompatibilities among the macromonomer, comonomer, and propagating polymer chain, together with the fact that methacrylate itself is much more influenced by the polymerization conditions than a styrenic monomer.

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Synthesis and characterization of chiral poly(l‐lactide‐b‐hexyl isocyanate) macromonomers with norbornenyl end groups and their homopolymerization through ring opening metathesis polymerization to afford polymer brushes

Choinopoulos

Koïnis

Pitsikalis

2017

J. Polym. Sci. Part A: Polym. Chem.

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We report the synthesis of the novel half-titanocene alkoxide complex bischloro-g 5 -cyclopentadienyl(bicyclo[2.2.1]hept-5-en-2-oxy) titanium (IV), [CpTiCl 2 (O-NBE)]. This complex was employed for the synthesis of chiral poly(L-lactide-b-hexyl isocyanate) diblock copolymer bearing a norbornene end group with sequential addition of monomers. The poly(hexyl isocyanate) block is chiral due to the last L-lactide unit of the poly(L-lactide) block. This macromonomer was polymerized towards a chiral polymer brush structure with polynorbornene backbone and chiral poly(L-lactide-b-hexyl isocyanate) side chains using Grubbs first-generation catalyst. The polymers were characterized using size exclusion chromatography (SEC), nuclear magnetic resonance (NMR), and circular dichroism (CD) spectroscopy and their thermal properties were investigated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) analysis.

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Preparation of α-, ω-End-Functionalized Poly(n-hexyl isocyanate) Heterotelechelics

Cited by 13 publications

References 23 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

Synthesis of Oligo(oxyethylene) Methacrylate-ended Poly(n-hexyl isocyanate) Rodlike Macromonomers and Their Radical Copolymerization Behavior with Methyl Methacrylate

Synthesis and characterization of chiral poly(l‐lactide‐b‐hexyl isocyanate) macromonomers with norbornenyl end groups and their homopolymerization through ring opening metathesis polymerization to afford polymer brushes

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