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Author

Makoto Kato

Other affiliations: Denso
Bio: Makoto Kato is an academic researcher from Toyota. The author has contributed to research in topics: Polymer & Polyolefin. The author has an hindex of 24, co-authored 117 publications receiving 5633 citations. Previous affiliations of Makoto Kato include Denso.


Papers
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Journal ArticleDOI
Masaya Kawasumi1, Naoki Hasegawa1, Makoto Kato1, and Arimitsu Usuki1, Akane Okada1 
TL;DR: In this paper, the dispersibility of 10-A-thick silicate layers of the clays in the hybrid was investigated by using a transmission electron microscope and X-ray diffractometer.
Abstract: Polypropylene (PP)−clay hybrids (PPCH) have been prepared by simple melt-mixing of three components, i.e., PP, maleic anhydride modified polypropylene oligomers (PP-MA), and clays intercalated with stearylammonium. The dispersibility of 10-A-thick silicate layers of the clays in the hybrids was investigated by using a transmission electron microscope and X-ray diffractometer. It is found that there are two important factors to achieve the exfoliated and homogeneous dispersion of the layers in the hybrids: (1) the intercalation capability of the oligomers in the layers and (2) the miscibility of the oligomers with PP. Almost complete hybrids were obtained in the case where the PP-MA has both intercalation capability and miscibility. The hybrids exhibit higher storage moduli compared to those of PP especially in the temperature range from Tg to 90 °C. The highest relative storage modulus at 80 °C of the hybrid based on a mica and the miscible PP-MA is as high as 2.0 to that of PP and is 2.4 to that of the ...

1,379 citations

Journal ArticleDOI
Naoki Hasegawa1, Masaya Kawasumi1, Makoto Kato1, Arimitsu Usuki1, Akane Okada1 
TL;DR: In this paper, polypropylene-clay hybrid (PPCH) was prepared using a maleic anhydride-modified PP oligomer (PP-MA) as a compatibilizer.
Abstract: Polypropylene-clay hybrids (PPCH) were prepared using a maleic anhydride-modified PP oligomer (PP-MA) as a compatibilizer. PP was melt-blended with organophilic clay which was intercalated with PP-MA. In these PPCHs, the particles of silicate layers were dispersed at the nanometer level. The particles became smaller and were dispersed more uniformly, as the ratio of PP-MA to the clay was increased. The dynamic storage moduli of the PPCHs were higher than that of PP up to 130°C. For example, the modulus of the PPCH with 5 wt % clay and 22 wt % PP-MA was 1.8 times higher compared to that of PP at 80°C. As the dispersibility of the clays was improved, the reinforcement effect of the clays increased. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67: 87–92, 1998

667 citations

Journal ArticleDOI
TL;DR: The synthesis of polypropylene (PP) oligomer-clay intercalation compounds was studied by using three kinds of PP oligomers and organophylic clay.
Abstract: The synthesis of polypropylene (PP) oligomer—clay intercalation compounds was studied by using three kinds of PP oligomers and organophylic clay. PP oligomers were two types of maleic-anhydride-modified PP oligomers containing different amount of maleic anhydride groups and one type of hydroxy modified PP oligomer. Organophylic clay was sodium-ion-exchanged montmorillonite with octadecylammonium ion (C18—Mt). PP oligomer was mixed with C18—Mt at 200°C. Maleic-anhydride-modified PP oligomer, which was of high acid value type, and hydroxy-modified PP oligomer were intercalated between silicate layers of clay; and PP oligomer—clay intercalation compounds were synthesized successfully. But maleic-anhydride-modified PP oligomer, which was of low acid value type, was not intercalated. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 1781–1785, 1997

536 citations

Journal ArticleDOI
01 Apr 2002-Polymer
TL;DR: The tensile strength of the EPDM-clay hybrid loading 4-wt% clay exhibited 2.0 times higher value compared to that of neat EPDm at 25-°C.

315 citations


Cited by
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TL;DR: A review of the academic and industrial aspects of the preparation, characterization, materials properties, crystallization behavior, melt rheology, and processing of polymer/layered silicate nanocomposites is given in this article.

6,343 citations

Journal ArticleDOI
TL;DR: In this article, a review of polymer-layered silicate nanocomposites is presented, where the polymer chains are sandwiched in between silicate layers and exfoliated layers are more or less uniformly dispersed in the polymer matrix.
Abstract: This review aims at reporting on very recent developments in syntheses, properties and (future) applications of polymer-layered silicate nanocomposites. This new type of materials, based on smectite clays usually rendered hydrophobic through ionic exchange of the sodium interlayer cation with an onium cation, may be prepared via various synthetic routes comprising exfoliation adsorption, in situ intercalative polymerization and melt intercalation. The whole range of polymer matrices is covered, i.e. thermoplastics, thermosets and elastomers. Two types of structure may be obtained, namely intercalated nanocomposites where the polymer chains are sandwiched in between silicate layers and exfoliated nanocomposites where the separated, individual silicate layers are more or less uniformly dispersed in the polymer matrix. This new family of materials exhibits enhanced properties at very low filler level, usually inferior to 5 wt.%, such as increased Young’s modulus and storage modulus, increase in thermal stability and gas barrier properties and good flame retardancy.

5,901 citations

Journal ArticleDOI
TL;DR: Modulus, ultimate strength and thermal stability follow a similar trend, with values for functionalized graphene sheet- poly(methyl methacrylate) rivaling those for single-walled carbon nanotube-poly(methyl methamphetamine) composites.
Abstract: Polymer-based composites were heralded in the 1960s as a new paradigm for materials. By dispersing strong, highly stiff fibres in a polymer matrix, high-performance lightweight composites could be developed and tailored to individual applications. Today we stand at a similar threshold in the realm of polymer nanocomposites with the promise of strong, durable, multifunctional materials with low nanofiller content. However, the cost of nanoparticles, their availability and the challenges that remain to achieve good dispersion pose significant obstacles to these goals. Here, we report the creation of polymer nanocomposites with functionalized graphene sheets, which overcome these obstacles and provide superb polymer-particle interactions. An unprecedented shift in glass transition temperature of over 40 degrees C is obtained for poly(acrylonitrile) at 1 wt% functionalized graphene sheet, and with only 0.05 wt% functionalized graphene sheet in poly(methyl methacrylate) there is an improvement of nearly 30 degrees C. Modulus, ultimate strength and thermal stability follow a similar trend, with values for functionalized graphene sheet- poly(methyl methacrylate) rivaling those for single-walled carbon nanotube-poly(methyl methacrylate) composites.

3,245 citations

Journal ArticleDOI
07 Jul 2008-Polymer
TL;DR: In this paper, the technology involved with exfoliated clay-based nanocomposites and also include other important areas including barrier properties, flammability resistance, biomedical applications, electrical/electronic/optoelectronic applications and fuel cell interests.

2,917 citations

Journal ArticleDOI
TL;DR: Delamination of LDHs is an interesting route for producing positively charged thin platelets with a thickness of a few atomic layers, which can be used as nanocomposites for polymers or as building units for making new designed organic- inorganic or inorganic-inorganic nanomaterials.
Abstract: Layered double hydroxides (LDHs) are a class of ionic lamellar compounds made up of positively charged brucite-like layers with an interlayer region containing charge compensating anions and solvation molecules. Delamination of LDHs is an interesting route for producing positively charged thin platelets with a thickness of a few atomic layers, which can be used as nanocomposites for polymers or as building units for making new designed organic-inorganic or inorganic-inorganic nanomaterials. The synthesis of nanosized LDH platelets can be generally classified into two approaches, bottom-up and top-down. It requires modification of the LDH interlamellar environment and then selection of an appropriate solvent system. In DDS intercalated LDHs, the aliphatic tails of the DDS- anions exhibit a high degree of interdigitation in order to maximize guest-guest dispersive interactions. Bellezza reported that the LDH colloids can also been obtained by employing a reverse microemulsion approach.

2,616 citations