Takumitsu Kida

Strong adhesion of high-density polyethylene (HDPE) and isotactic polypropylene (iPP) with ethylene-styrene-butadiene (ESB) copolymers

Takumitsu Kida, Taiki Sekoguchi, Mana Ichii, Shusuke Kanomi et autres

Polyethylene (PE) and isotactic polypropylene (iPP) are the most widely used semi-crystalline polyolefins, but their inherent immiscibility limits the bonding of dissimilar polyolefins and the upcycling of mixed waste streams. Conventional compatibilizers, such as olefin block copolymers (OBCs), bridge the PE/iPP interface …

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Improved Heat Resistance of Polypropylene with Added Sorbitol Derivatives

Shohei Iwasaki, Mitsuko Inoue, Takahiro Inoue, Takumitsu Kida et autres

The influence of injection-molding temperature on the mechanical and thermal properties of isotactic polypropylene (PP) containing 0.4 wt.% of the nucleating agent 1, 3:2, 4-bis-O -(4-methylbenzylidene)-D -sorbitol (MDBS) was investigated. Isothermal crystallization measurements performed by differential scanning calorimetry revealed that MDBS at …

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Molecular-Weight Dependence of Tensile Properties of Nearly Monodisperse Linear Polyethylene Solids Synthesized Using a Phenoxyimine Catalyst

Takumitsu Kida, Ryō Tanaka, Yusuke Hiejima, Hiroki Takeshita et autres

The molecular-weight dependence of the tensile deformation of semi-crystalline polymers is complicated by their supermolecular structure. In this study, we systematically investigated the tensile properties of linear polyethylene (PE) using a unique series of nearly monodisperse samples ( M w / M …

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AWPP 2025 (Kanazawa, Japan)

Takumitsu Kida

Unveiling Distinct Humidity Sensitivity of Relaxation Properties in Vitrimer‐Like Materials with Hydrophilic, Bond Exchangeable Domains

Mikihiro Hayashi, Maho Suzuki, Shinji Suzuki, Koichi Maumi et autres

Trans-N-alkylation reactions have frequently served as bond exchange mechanisms in vitrimer-like materials, enabling sustainable functionality governed by relaxation dynamics. As a unique class of these materials, we have studied nano-phase-separated systems containing nanodomains of quaternized pyridines that undergo trans-N-alkylation bond exchange. In …

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Effects of stirring time on formation of microplastics fragmented from photo-aged polypropylene

Kazuya Haremaki, Takumitsu Kida, Yusuke Koide, Takashi Uneyama et autres

This paper examines the evolution of microplastic (MP) size distributions fragmented from photo-aged polypropylene (PP) in stirred water. PP specimens fragmented into MPs with their size of 1-30 μm after UV irradiation and stirring in laboratory settings. These laboratory-fragmented MPs were dispersed …

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Conference Report on the 9th Asia-Pacific Rim Conference on Rheology (A-PRCR2025)

Takumitsu Kida

The Pacific Rim Conference on Rheology (PRCR) is an international conference held every four years, bringing together rheologists from across the Pacific Rim.The previous conference was held in 2023 in Vancouver, Canada, shortly after the COVID-19 pandemic, and this time it was …

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Synthesis of long-chain branched multiblock polyolefin composed of isotactic polypropylene and ethylene-propylene copolymers via polymer cross-metathesis

Yuta Yanagi, Takumitsu Kida, Ryo Tanaka, Yuushou Nakayama et autres

Abstract Multiblock copolymers consisting of isotactic polypropylene ( i PP) and ethylene–propylene rubber (EPM) were successfully synthesized by cross-metathesis between these polymers bearing a small number of C = C bonds in the main chain. The C = C bonds for metathesis …

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Effect of Low‐Density Polyethylene on the Processability of a Tubular‐Blown Polypropylene Film

Yoko Fujii, Hoang‐Giang Dai Vo, Takumitsu Kida, Masayuki Yamaguchi et autres

ABSTRACT The effect of low‐density polyethylene (LDPE) on the processability of a tubular‐blown film of isotactic polypropylene (PP) was determined by evaluating its structure and mechanical properties. The LDPE addition provided strain hardening in transient elongational viscosity, and furthermore enhanced the flow‐induced …

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Crystallization of Biobased Long-Chain Aliphatic Polyesters as Sustainable Polymers: Effects of the Diol Structure in the Monomer Unit

Hiroki Takeshita, Akira Nishiyama, Xiuxiu Wang, Mika Kojima et autres

Abstract Biobased polyesters, recyclable sustainable polymers derived from renewable feedstock, are promising alternatives to petroleum-based polymers. The crystallization behavior, crystal structure, and supramolecular structures of a series of biobased long-chain aliphatic polyesters, consisting of a diester of 10-undecenoic acid with isosorbide (IS), …

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Microscopic load sharing of molecular chains of polyethylene solids with different structural variables evaluated by Rheo-Raman spectroscopy

Takumitsu Kida, Sanshiro Kimura, Hiroki Takeshita, Katsuhisa Tokumitsu

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Influence of Heat Treatment on Amorphous Structure and Mechanical Properties of Isosorbide-Based Bio-Polycarbonate

Kohei Kurihara, Hajime Nakajima, Takumitsu Kida, Hiroki Takeshita et autres

In the present study, we evaluated the influence of heat treatment on the amorphous structure and mechanical properties of isosorbide-derived bio-based polycarbonate (Bio-PC) to enhance its functionality. We compared the physical and mechanical properties of Bio-PC with those of petroleum-based polycarbonate (Petro-PC) …

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