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

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

doi:10.1295/polymj.pj2008165

Cited by 4 publications

(4 citation statements)

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“…In previous papers, we reported the synthesis and characterization of rod-like styryl-ended or α-methacryloyl-ω-acetyl ended poly( n -hexyl isocyanate) (PHIC) macromonomers (VB-HIC- N s − or MA-HIC- N s , − where N s is the weight-averaged degree of polymerization of HIC), their radical copolymerizabilities, , and conformational properties of the resulting rod brushes. ,, The value of λ M –1 of the rod brushes linearly increased with the increasing of N s that followed the scaling law of λ M –1 ∝ N s 1 . The observed power law exponent value could not be explained by the theories for the rod brushes …”

Section: Introductionmentioning

confidence: 99%

Graft Density Dependence of Main Chain Stiffness in Molecular Rod Brushes

et al. 2015

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The graft density dependence of main chain stiffness in rod brushes composed of a flexible linear polystyrene (PS) main chain and poly(n-hexyl isocyanate) (PHIC) rod side chains has thoroughly been investigated by static light (LS) and small-angle Xray scattering (SAXS) measurements in tetrahydrofuran (THF) at 25°C. A series of statistical graft copolymers having different graft densities (σ) and graft chain lengths (PS-g-HIC-N s -l g , where N s is the weight-averaged degree of polymerization of HIC and l g is the average distance (spacing) of the main chain between the side chain joints) were prepared by the nearly azeotrope radical copolymerizations of styrene (M 1 ) with PHIC macromonomers (M 2 ) (r 1 = 0.84 ± 0.1 and r 2 = 1.1 ± 0.3) in n-hexane or the bulk at 60°C. The compositional heterogeneities of the graft copolymers were carefully characterized by the ratio of the UV to RI signal in the SEC traces and the comparison with those predicted from the theory by Stejskal and Kratochvil [Macromolecules 1987, 20, 2624], implying that they were sufficiently small enough to allow one to study their dimensional characterizations. The graft density dependence of the root-mean-square cross-section radius of gyration (⟨S c 2 ⟩ 1/2 ) and the z-averaged root-mean-square radius of gyration (⟨S 2 ⟩ z 1/2 ) of PS-g-HIC-N s -l g was studied and rationalized as the function of σ and N s . The σ-dependence of ⟨S c 2 ⟩ 1/2 could be quantitatively described by the theory for the semiflexible comb whose main and side chains have different chain stiffness. The weight-averaged degree of polymerization of the main chain (N M ) dependence of ⟨S 2 ⟩ z 1/2 was also quantitatively described by the cylindrical wormlike chain model. It was found that the change in the main chain stiffness (λ b −1

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Section: Introductionmentioning

confidence: 99%

Graft Density Dependence of Main Chain Stiffness in Molecular Rod Brushes

et al. 2015

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“…Hydrogen atoms of the methylene groups of PHIC were as follow: (d, e, f, 1.263–1.326 ppm), (g, 1.445–1.521ppm), (h, 3.615–3.682 ppm). 19,20,23,24,30 The end of the chain (i) gives a weak peak at 7.074 ppm. 30,35,44 Number-average molecular weight (normalM¯normaln) and the number of units in each block of the copolymer were calculated from the 1 H NMR spectrum by the following equation 45 :Where I a , I c , and I i are the integrals of a, c, and i signals in Figure 2.…”

Section: Resultsmentioning

confidence: 99%

“…Recently, poly (n-hexyl isocyanate) (PHIC) and its copolymers have attracted considerable attention because of their potential applications and unique properties in areas such as chiral recognitions, optical switches, liquid crystals, degradable materials, nanocomposites, blend of polymers, electrical devices, biomaterials, nanowires, thermoreversible gels, and activators. [17][18][19][20][21][22][23][24][25][26][27][28][29][30][31] These copolymers are so important that various behaviors of linear and nonlinear block copolymers based on PHIC have been investigated by Vazaios et al 32 The known methods used for copolymerization of PHIC are reported in Table 1.…”

Section: Introductionmentioning

confidence: 99%

High-performance family of polymeric particles prepared from poly(phenylene oxide)-poly(hexyl isocyanate) liquid crystal block copolymer: synthesis and properties study

Semsarzadeh

Dadkhah

Sabzevari

2022

Polymers and Polymer Composites

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The poly (phenylene oxide)-block-poly (hexyl isocyanate) copolymers (PPO-b-PHIC)s were synthesized in various ratios of blocks using the organotitanium coordination method at room temperature. The copolymer particles were prepared by precipitation of concentrated solution of the copolymers in non-solvent under stirring. The synthesized copolymers and their particles were characterized by 1H and 13C nuclear magnetic resonance (1H and 13C NMR), Fourier transform infrared (FTIR) spectra, differential scanning calorimetry (DSC), polarized optical microscope (POM), thermogravimetric analysis (TGA) and scanning electron microscope (SEM). The effect of block ratio on the anisotropic-isotropic transition and liquid crystal texture of copolymers as a function of temperature and concentration of the solution was investigated. The polymeric particles tend to be aligned along the fibrillar direction by increasing the block ratio of amide in the copolymer.

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“…The details of the preparation and characterization of the macromonomer have been described in previous papers. [31][32][33] Briefly, the initiator, HEMACpTiCl 2 , was synthesized as follows. In a dry box, a solution of HEMA (4.56 mmol) in 5 ml of dry THF was slowly added to a solution of trichlorocyclopentadienyl titanium (4.56 mmol) in 5 ml of dry THF in a 50 ml three-necked flask with a magnetic stir bar and a tube containing dry triethylamine to trap the produced HCl.…”

Section: Preparation Of Phic Macromonomer (Ma-hic-61-ac)mentioning

confidence: 99%

Influence of the primary structure of the main chain on backbone stiffness of cylindrical rod brushes

Saito

Lien

Jinbo

et al. 2012

Polym J

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The dimensional properties of rod brushes consisting of a flexible polymethacrylate main chain and poly(n-hexyl isocyanate; PHIC) rod side chains have been studied using static light and small-angle X-ray scattering (SAXS) techniques in tetrahydrofuran (THF) at 25 1C. The results are compared with those consisting of a flexible polystyrene main chain and PHIC side chains (VB-HIC-N s-H, where N s is the weight-averaged degree of polymerization of HIC). The rod brushes were prepared through the radical homopolymerizations of a-methacryloyloxyethoxy-x-acetyl-PHIC macromonomer (MA-HIC-61-Ac) in n-hexane at 60 1C. The molecular weight dependence of the z-averaged mean-square radius of gyration (/R g 2 S z) of the brush is quantitatively described in terms of the wormlike cylinder model taking into account the end effects. The main chain stiffness parameter (k M À1) is determined to be 197 nm for poly(MA-HIC-61-Ac), which is approximately three times greater than that for poly(VB-HIC-62-H), which has a polystyrene main chain and the same rod length. The considerably larger stiffness in the polymethacrylate than in the polystyrene is most likely responsible for the larger effective excluded volume effects produced by the freely rotating spacer between the main chain and side rod. A single rod brush of poly(MA-HIC-61-Ac) on a mica surface is clearly observed using atomic force microscopy to reasonably demonstrate the cylindrical rod brushes.

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

Cited by 4 publications

References 28 publications

Graft Density Dependence of Main Chain Stiffness in Molecular Rod Brushes

Graft Density Dependence of Main Chain Stiffness in Molecular Rod Brushes

High-performance family of polymeric particles prepared from poly(phenylene oxide)-poly(hexyl isocyanate) liquid crystal block copolymer: synthesis and properties study

Influence of the primary structure of the main chain on backbone stiffness of cylindrical rod brushes

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