Graft copolymerization of styrene onto polyisoprene was carried out to explore the possibility for recycling waste rubber into useful materials. Natural rubber (Mn= 266000) converted to the corresponding polymers with lower molecular weight by heating at 300°C under an air or nitrogen atmosphere (air : Mn= 23600, N₂ : Mn= 37600), respectively. Further, the radical copolymerization of lower molecular weight polyisoprene (Mn= 9910; 44 mmol per a natural rubber unit) with styrene (44 mmol) was carried out in bulk at 80°C for 2h, in the presence of 2, 2'-azobis (isobutyronitrile) (5 mol%) under the air atmosphere, resulting in giving the corresponding grafted copolymer in 88.6 % yield, the composition of which was 1 / 1.12 ([isoprene unit] / [styrene unit])

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Composite films composed of a polyimide, an epoxy resin and a silver filler were prepared. Thermal and mechanical properties of the composite films were studied in detail via dynamic mechanical analysis, thermal mechanical analysis, and tensile tests. Furthermore, the morphological change of the films with increasing silver filler content was discussed through comparison between experimental and theoretical data calculated from the certain rules of mixture about modulus and coefficient of thermal expansion. These analyses suggested that fillers would restrict the phase separation and the microbrownian motion of the matrix resin. As the filler volume content increases, the distance between the adjacent flake-like fillers decreases, resulting in the promotion of the above effects. On the other hand, while the addition of the epoxy resin mechanically reinforces the film by the formation of the network structure, its excessive addition makes the film be brittle by the increased crosslinking density, resulting in a peak in tensile strength at 20 phr epoxy resin content.

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Toughening was investigated on a self-adhesive matrix resin,-for high performance composites. Carboxyl-modified acrylonitrile-butadiene rubber was fractionated to use as modifiers. The matrix resin was a mixture consisting of tetraglycidyl diaminodiphenyl methane, dicyclopentadienyl-type epoxy resin and bisphenol A diglycidylether epoxy resin, and cured with 4, 4'-diaminodiphenyl sulfone. The effectiveness of a modifier as a toughener depended on its molecular weight and amount added. The modifiers, having Mw 110,000 and 300,000, were effective for toughening the matrix resin : 50% increase in the fracture toughness was attained by modifying. But a the higher molecular weight modifier (Mw 590,000) was less effective for toughening. In examining the modified resin morphology by SEM and TEM, sea and island structures with well-dispersed rubber particles were observed in the content of 5phr or 10phr rubber (Mw 110,000). When using the higher molecular weight rubber (Mw 300,000) in the same amount, also the sea and island structures were observed with the existence of rubber particles slightly aggregated. Anyway, both morphologies were effective to enhance the toughness of the matrix resin.

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Preparation of a new class of organic/inorganic polymer hybrid (nano glass) (3) from novolac (1) is described. 3 was prepared by the acid-catalyzed sol-gel reaction of phenyltrimethoxysilane (PhTMOS) (2) in the presence of 1. 3 was transparent film and showed high heat stability. The dispersion of two components was the utilization of π-π interaction between phenyl ring of silica matrix and that of novolac.

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Organic-inorganic hybrid materials have been produced by using the sol-gel process originating in inorganic chemistry with the organic metal chemistry originating in organic chemistry. The purpose is the development of a highly useful material by hybridization. Research aiming at designing the material with a new structure and performance has also been increasing notably in the past several years.
Especially, organic silicon chemistry attained the molecular design and composition of organic-inorganic hybrid materials similar to organic polymers. For example, of polysilsesquioxanes (T8) having a cage structure was co-polymerized with the organic compound (diyne) to produce T8 diyne, which was excellent in heat resistance, mechanical, and dielectric properties.
Further research has been studied on reaction control for minimizing the particle size of MOx, for self-organization in the inorganic compounds besides silicon, and so on. The possibility of creating the transparent conductivity film was suggested by our company through the hybridization of ITO nano particles with soluble polypyrol.

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Today, so-called “Plastic Lining” has been much interested in anti-corrosion related fields.
The word “Lining” originally means a sort of coating which is coated on the interior surface of a container, like a “liner” called as the interior side of Western style clothes. The purpose of the lining is not only to protect the substance of container from being corroded, but also to keep the contents clean, by selecting an appropriate anti-corrosive material for lining without exuding or penetrating any contaminating ingredients.
So, the lining film thickness has to be relatively thicker for protecting the substrate from the penetration of environments (gases and or liquids). The clear and authorized definition of the word “Lining” can not be found, even so, we can get a good understanding in ASTM D 5161-96 with a better explanation close to definition. There are two categories of “Lining”. One is “Water-proofing” and another is “Anti-corrosion”.
From the standpoint of demand, a market size of the former seems to be larger than that of the latter. Though there can be found some differences between them in such as anti-corrosion performance, those are going on to be adjusted. The history of “Lining” is so long that wood, bricks, ceramics (glass), lead rubber and so forth have been applied.
In the beginning of the 20^th century, thanks to the good development of coal and petroleum chemical industries, many kinds of plastic lining have been used and become well-known. Also, in lining technologies, the mechanical strength of lining layers is much improved by reinforcing fibers.
“FRP Water-proofing” is now becoming popular from these reasons.
In a series of reports on “Plastic Lining-Trends”, to begin with the authors summarize “FRP Water-proofing, echnologies and trends with plastics” which is much common and closer to everyday people.

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