Author
Shiro Kobayashi
Other affiliations: Tohoku University, Iwate University, Max Planck Society ...read more
Bio: Shiro Kobayashi is an academic researcher from Kyoto University. The author has contributed to research in topics: Polymerization & Monomer. The author has an hindex of 63, co-authored 566 publications receiving 15902 citations. Previous affiliations of Shiro Kobayashi include Tohoku University & Iwate University.
Papers published on a yearly basis
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TL;DR: The development of polymer-clay nanocomposite materials, in which nanometer-thick layers of clay are dispersed in polymers, was first achieved about 15 years ago as mentioned in this paper.
Abstract: The development of polymer-clay nanocomposite materials, in which nanometer-thick layers ofclay are dispersed in polymers, was first achieved about 15 years ago. Since then, the materialshave gradually become more widely used in applications such as automotive production. The first practicalnylon-clay nanocomposite was synthesized by a monomer intercalation technique; however, the productionprocess has been further developed and a compound technique is currently widely used. A polyolefinnanocomposite has been produced by the compound method and is now in practical use at small volumelevels. In this review, which focuses on nylon- and polyolefin-nanocomposites, detailed explanationsof production methods and material properties are described. This article contains mainly the authors’work, but aims to provide the reader with a comprehensive review that covers the works of otherlaboratories too. Lastly, the challenges and directions for future studies are included.
291 citations
274 citations
TL;DR: An overview on recent developments of oxidative polymerizations of phenols, particularly focusing on the coupling selectivity, can be found in this article, where three reaction mechanisms are discussed: coupling of free phenoxy radicals, coupling of the phenoxonium cation coordinated to catalyst complexes, and coupling through the phenoxide cation.
269 citations
TL;DR: This article describes the recent progress of enzymatic polymerization technique, developed mainly during this decade, which utilizes enzymes of hydrolases and oxidoreductases as catalysts.
Abstract: Enzymatic polymerization denotes an in vitro polymerization via nonbiosynthetic pathways catalyzed by an isolated enzyme. This article describes the recent progress of this polymerization technique, developed mainly during this decade. The polymerization utilizes enzymes of hydrolases and oxidoreductases as catalysts. This new method of polymer synthesis provided natural polysaccharides like cellulose, amylose, xylan, and chitin, and unnatural polysaccharides catalyzed by a glycosidase from well-designed monomers, various functionalized polyesters catalyzed by lipase from a variety of monomers, and polyaromatics materials catalyzed by an oxidoreductase and an enzyme model complex from phenols and anilines. An oxidoreductase also initiated vinyl polymerizations. Characteristic features of enzymatic polymerizations are discussed, including the importance of the combination of substrate monomer and enzyme. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 3041–3056, 1999
237 citations
214 citations
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TL;DR: The current knowledge in the structure and chemistry of cellulose, and in the development of innovative cellulose esters and ethers for coatings, films, membranes, building materials, drilling techniques, pharmaceuticals, and foodstuffs are assembled.
Abstract: As the most important skeletal component in plants, the polysaccharide cellulose is an almost inexhaustible polymeric raw material with fascinating structure and properties. Formed by the repeated connection of D-glucose building blocks, the highly functionalized, linear stiff-chain homopolymer is characterized by its hydrophilicity, chirality, biodegradability, broad chemical modifying capacity, and its formation of versatile semicrystalline fiber morphologies. In view of the considerable increase in interdisciplinary cellulose research and product development over the past decade worldwide, this paper assembles the current knowledge in the structure and chemistry of cellulose, and in the development of innovative cellulose esters and ethers for coatings, films, membranes, building materials, drilling techniques, pharmaceuticals, and foodstuffs. New frontiers, including environmentally friendly cellulose fiber technologies, bacterial cellulose biomaterials, and in-vitro syntheses of cellulose are highlighted together with future aims, strategies, and perspectives of cellulose research and its applications.
6,098 citations
TL;DR: Reaction Mechanism, Synthesis of Urea and Urethane Derivatives, and Alcohol Homologation 2382 10.1.
Abstract: 4.3. Reaction Mechanism 2373 4.4. Asymmetric Synthesis 2374 4.5. Outlook 2374 5. Alternating Polymerization of Oxiranes and CO2 2374 5.1. Reaction Outlines 2374 5.2. Catalyst 2376 5.3. Asymmetric Polymerization 2377 5.4. Immobilized Catalysts 2377 6. Synthesis of Urea and Urethane Derivatives 2378 7. Synthesis of Carboxylic Acid 2379 8. Synthesis of Esters and Lactones 2380 9. Synthesis of Isocyanates 2382 10. Hydrogenation and Hydroformylation, and Alcohol Homologation 2382
3,203 citations
TL;DR: In this article, the authors summarize the basic physical concepts and the microstructural features of equilibrium and non-equilibrium nanostructured materials (NsM) and make an attempt to summarize their properties.
2,629 citations
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
TL;DR: It is proposed that the exponential and power function models of the species-area relationship result from the way in which individuals are distributed among species, and specific values of the slope of the power function are often construed to * Order of authorship determined by the toss of a coin.
Abstract: Regional differences in species number have puzzled naturalists ince the early 1800's, and explanations account for a large part of modern ecological research. Two venerable observations form the cornerstone of our knowledge on the subject: The number of species within a taxonomic group tends to increase with decreasing latitude (see Fischer 1960; Pianka 1966); and the number of species within a taxonomic group tends to increase with increasing area (see Preston 1960, 1962; Williams 1964; MacArthur and Wilson 1967; Simberloff 1972). Despite early research on the latter trend (the species-area relationship), ecologists have studied it intensely only in the last 50 yr. The relationship was originally envisioned as an empirical tool and used in three principle ways: (1) to determine optimal sample size and sample number, (2) to determine the minimum area of a \"community,\" and (3) to predict the number of species in areas larger than those sampled. All three uses are discussed by Kilburn (1966). More recently interest in the species-area relationship has focused on mechanistic explanations, its precise mathematical descriptions, and interpretations of parameters derived from these mathematical descriptions. Williams (1964) and Preston (1960, 1962) have proposed that the exponential and power function models (\"exponential model\" throughout his paper also refers to the species/log area transformation, and \"power function\" also refers to the log species/log area transformation) of the species-area relationship result from the way in which individuals are distributed among species. Williams' (1964) exponential model, which emphasizes habitat heterogeneity, was considered important by many plant ecologists but is now largely ignored. Preston's (1960, 1962) power function model was based on the assumption of a dynamic equilibrium of species exchanges between islands in an archipelago. This assumption led to the equation of the power function model with the idea of a dynamic equilibrium as expounded by MacArthur and Wilson (1963, 1967), such that an adequate fit of this model to observed species numbers has been viewed as support of the equilibrium hypothesis (Grant 1970; Diamond 1973; Simpson 1974). The interplay of the equilibrium hypothesis and the power function model of the species-area relationship has led to interpretation of the slope and intercept of the power function model exclusively in the context of the equilibrium hypothesis. In particular, specific values of the slope of the power function are often construed to * Order of authorship determined by the toss of a coin. t Present address: Department of Biology, University of South Florida, Tampa, Florida 33620. Am. Nat. 1979. Vol. 113, pp. 791-833. c) 1979 by The University of Chicago. 0003-0147/79/1306-0002$03.26
2,083 citations