研究者詳細 - 増渕　雄一

論文 - 増渕　雄一

分割表示 212 件中 41 - 60 件目／全件表示 >>

Primitive Chain Network Simulations of Entangled Melts of Symmetric and Asymmetric Star Polymers in Uniaxial Elongational Flows 査読有り国際共著国際誌

Masubuchi Y., Ianniruberto G., Marrucci G.

Nihon Reoroji Gakkaishi 49 巻 ( 3 ) 頁： 171 - 178 2021年

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Nihon Reoroji Gakkaishi

Ianniruberto and Marrucci [Macromolecules, 46, 267-275, 2013] developed a theory whereby entangled branched polymers behave like linear ones in fast elongational flows. In order to test such prediction, Huang et al [Macromolecules, 49, 6694-6699, 2016] performed elongational measurements on star polymer melts, indeed revealing that, in fast flows, the elongational viscosity is insensitive to the molecular structure, provided the molecular weight of the "backbone" (spanning the largest end-to-end distance of the molecule) is the same. Inspired by these studies, we here report on results obtained with multi-chain sliplink simulations for symmetric and asymmetric star polymer melts, as well as calculations of the Rouse time of the examined branched structures (not previously determined by Ianniruberto and Marrucci). The simulations semi-quantitatively reproduce the experimental data if the Kuhn-segment orientation-induced reduction of friction (SORF) is accounted for. The observed insensitivity of the nonlinear elongational viscosity to the molecular structure for the same span molar mass may be due to several factors. In the symmetric case, the calculated Rouse time of the star marginally differs from that of the linear molecule, so that possible differences in the observed stress fall within the experimental uncertainty. Secondly, it is possible that flow-induced formation of hooked star pairs (or even larger aggregates) makes the effective Rouse time of the aggregate even closer to that of the linear polymer because the friction center moves towards the branchpoint of the star molecule. In the asymmetric case, it is shown that the stress contributed by the short arms is negligible with respect to that of the long ones. However, such stress reduction is balanced by a dilution effect whereby the unstretched arms reduce SORF as they decrease the Kuhn-segment order parameter of the system. As a result of that dilution, the stress contributed by the backbone is larger. The two effects compensate one another, so that the overall stress is virtually the same of the other architectures.

DOI： 10.1678/rheology.49.171

Scopus

Elasticity of Randomly Cross-Linked Networks in Primitive Chain Network Simulations 査読有り国際誌

Masubuchi Y.

Nihon Reoroji Gakkaishi 49 巻 ( 2 ) 頁： 73 - 78 2021年

担当区分：筆頭著者,　最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Nihon Reoroji Gakkaishi

Primitive chain network simulations for randomly cross-linked slip-link networks were performed. For the percolated networks, the stress-strain relationship was compared to the theories by Ball et al. [Polymer, 22, 1010 (1981)] and Rubinstein and Panyukov [Macromolecules, 35, 6670 (2002)]. The simulation results are reasonably reproduced by both theories when the contributions from cross-links and slip-links are determined irrespective of the network structure. The fraction of slip-links contained in the network thus obtained is model dependent, and it does not coincide with the number of active slip-links in the actual networks. This discrepancy between the theories and the simulation results is due to the network inhomogeneity.

DOI： 10.1678/rheology.49.73

Scopus

Linear Rheological Properties of Poly(Propylene Carbonate) with Different Molecular Weights 査読有り国際誌

Yang Lixin, Uneyama Takashi, Masubuchi Yuichi, Doi Yuya

Nihon Reoroji Gakkaishi 49 巻 ( 4 ) 頁： 267 - 274 2021年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：一般社団法人日本レオロジー学会

<p>The linear viscoelastic properties of poly(propylene carbonate) (PPC) melts having different molecular weights and narrow molecular weight distributions were studied. Some linear viscoelasticity parameters, including the plateau modulus and zero shear viscosity of PPC, were evaluated. The entanglement molecular weight of PPC was estimated to be 5.9 kg/mol, which is considerably lower than that previously reported for PPC with a broad molecular weight distribution.</p>

DOI： 10.1678/rheology.49.267

Complex Network Representation of the Structure-Mechanical Property Relationships in Elastomers with Heterogeneous Connectivity 査読有り国際誌

Yoshifumi Amamoto, Ken Kojio, Atsushi Takahara, Yuichi Masubuchi, TakaakiOhnishi

Patterns 1 巻 ( 8 ) 頁： 100135-1 - 100135-9 2020年11月

Short-time dynamics of a tracer in an ideal gas 査読有り国際誌

Nakai Fumiaki, Masubuchi Yuichi, Uneyama Takashi

PHYSICAL REVIEW E 102 巻 ( 3 ) 頁： 032104-1 - 032104-12 2020年9月

Primitive chain network simulations for the interrupted shear response of entangled polymeric liquids 査読有り国際誌

Yuichi Masubuchi, Yuya Doi, Takashi Uneyama

SOFT MATTER 16 巻 ( 28 ) 頁： 6654 - 6661 2020年7月

Fracture strain of composite with nonuniformly distributed reinforcing fibers 査読有り国際誌

Yamamoto Tetsuya, Masubuchi Yuichi, Doi Masao

JOURNAL OF RHEOLOGY 64 巻 ( 4 ) 頁： 933 - 939 2020年7月

Primitive chain network simulations for H-polymers under fast shear 査読有り国際共著国際誌

Masubuchi Yuichi, Ianniruberto Giovanni, Marrucci Giuseppe

SOFT MATTER 16 巻 ( 4 ) 頁： 1056 - 1065 2020年1月

Effects of Constraint-Release on Entangled Polymer Dynamics in Primitive Chain Network Simulations 査読有り国際誌

Masubuchi Yuichi

NIHON REOROJI GAKKAISHI 48 巻 ( 1 ) 頁： 37 - 42 2020年

Simulations of Startup Planar Elongation of an Entangled Polymer Melt 査読有り国際誌

Takeda Keiko, Masubuchi Yuichi, Sugimoto Masataka, Koyama Kiyohito, Sukumaran Sathish K.

NIHON REOROJI GAKKAISHI 48 巻 ( 1 ) 頁： 43 - 48 2020年

Multi-chain slip-spring simulations for polyisoprene melts 招待有り査読有り国際誌

Masubuchi Yuichi, Uneyama Takashi

KOREA-AUSTRALIA RHEOLOGY JOURNAL 31 巻 ( 4 ) 頁： 241 - 248 2019年11月

Retardation of Reaction Kinetics of Polymers due to Entanglement in Post-Gel Stage in Multi-Chain Slip-Spring Simulations 査読有り国際誌

Yuichi Masubuchi, Takashi Uneyama

Soft Matter 15 巻頁： 5109 – 5115 2019年6月

Characterization of critical gel state of polyamides by viscoelastic, thermal, and IR measurements 査読有り国際誌

Hirayama Takaya, Uneyama Takashi, Masubuchi Yuichi

RHEOLOGICA ACTA 58 巻 ( 5 ) 頁： 281 - 290 2019年5月

Contraction of Entangled Polymers After Large Step Shear Deformations in Slip-Link Simulations 招待有り査読有り国際誌

Masubuchi Yuichi

POLYMERS 11 巻 ( 2 ) 2019年2月

Comparison among multi-chain simulations for entangled polymers under fast shear 査読有り国際誌

Yuichi Masubuchi, Takashi Uneyama

ECS Transactions 88 巻 ( 1 ) 頁： 161-167 - 167 2019年2月

Effect of inertia on linear viscoelasticity of harmonic dumbbell model 査読有り国際誌

Takashi Uneyama, Fumiaki Nakai, Yuichi Masubuchi

Nihon Reoroji Gakkaishi 47 巻 ( 4 ) 頁： 143 - 154 2019年

担当区分：最終著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Nihon Reoroji Gakkaishi

<p>The overdamped (inertialess) dumbbell model is widely utilized to study rheological properties of polymers or other soft matters. In most cases, the effect of inertia is merely neglected because the momentum relaxation is much faster than the bond relaxation. We theoretically analyze the effect of inertia on the linear viscoelasticity of the harmonic dumbbell model. We show that the momentum and bond relaxation modes are kinetically coupled and the inertia can affect the bond relaxation if the momentum relaxation is not sufficiently fast. We derive an overdamped Langevin equation for the dumbbell model, which incorporates the weak inertia effect. Our model predicts the bond relaxation dynamics with the weak inertia effect correctly. We discuss how the weak inertia affects the linear viscoelasticity of a simple harmonic dumbbell model and the Rouse model.</p>

DOI： 10.1678/rheology.47.143

Scopus

Nonlinear Elongational Rheology of Unentangled Polystyrene and Poly(p-tert-butylstyrene) Melts 査読有り国際共著国際誌

Matsumiya Yumi, Watanabe Hiroshi, Masubuchi Yuichi, Huang Qian, Hassager Ole

MACROMOLECULES 51 巻 ( 23 ) 頁： 9710 - 9729 2018年12月

Relaxation Dynamics of Surface Fluctuations of Foam Films Decorated by Gel-Like Polymer-Surfactant Complexes 査読有り国際誌

Isoda Takuma, Masubuchi Yuichi, Yamamoto Tetsuya

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN 87 巻 ( 10 ) 2018年10月

Relaxation of Rouse Modes for Unentangled Polymers Obtained by Molecular Simulations 査読有り国際誌

Yuichi Masubuchi, Hiroto Takata, Yoshifumi Amamoto and Tetsuya Yamamoto

Nihon Reoroji Gakkaishi 46 巻 ( 4 ) 頁： 171-178 2018年9月

Comparison among multi-chain models for entangled polymer dynamics 査読有り国際誌

Masubuchi Yuichi, Uneyama Takashi

SOFT MATTER 14 巻 ( 29 ) 頁： 5986-5994 2018年8月

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