Dismantlable adhesives, which achieve enough adhesion strength in use and easy debonding on demand,have attracted much attention from industrial and academic perspectives. Dismantlable adhesives are one ofpromising materials and technology for resource and energy savings. In this review article, the examples ofdismantlable adhesives based on various stimuli-responsive polymeric materials were introduced. Especially,design and development of dismantlable adhesives using reactive polymers, such as degradable polymers,cross-linkable polymers, and side-chain reactive polymers, were explained in detail.

Bamboo, perennial woody grass, grows widely in zones with a wet season ranging from the tropics totemperate areas. It grows faster than any woody plant, and its uses have, since ancient times, ranged frombasic tools to industrial materials. Recently, some studies implied that bamboo has a potential as fiber crop forthe production of cellulose nanofibers. They have attracted significant interest because of their high Young’smodulus, high strength, and low coefficient of thermal expansion, combined with low weight, biodegradability,and renewability. Bamboo cell wall have some chemical specifies as woody grass species. This review describesthe chemical characterization of bamboo and bamboo fibers and its potential use as reinforcing material suchas cellulose nanofiber.

Adhesion between zirconia as dental material and organic polymer as opaquer resin was confirmed to besufficiently strong using 3-methacryloyloxypropyltrimethoxysilane （MPTS） as a primer after sandblasting.Since pentaerythritol tetrakis ［3- (mercaptopropionate）］ acts as a primer for adhesion of precious metals,an ethanol solution of MPTS and the thiol was successfully utilized for the adhesion of opaquer irrespectiveof adherend. Application of the mixture as a multipurpose primer （ML） also enhanced the adhesive strengthafter thermalcycling whereas debonding occurred without priming. It should be emphasized that ML withoutany acidic compound, which might degrade MPTS, is featured by a long shelf-time. A stepped surfacestructure consisting of parallel grooves was carved on zirconia using a computer-aided design/computer-aidedmanufacturing system, and the surface structure was found to significantly strengthen adhesion to opaquer bysandblasting and priming with ML. A model of front tooth was prepared by building up of composite resin onzirconia or titanium frame, indicating that the fracture strength of the model was enhanced by priming withML to a level greater than that required by the actual occlusal force. Thus, the present study confirmed theutilities of ML as multipurpose primer and the stepped structure as effective surface treatment of zirconia.

The purpose of this study is clarifying the contamination source and suitable cleaning method of stainlesssteel（ SS） standard adherend for peel test of pressure-sensitive adhesives（ PSA）. For this purpose, fourkinds of PSA tapes consisting of rubber, polyacrylic polymer, styrenic block copolymer and silicone polymeras base polymer and SS foil as model adherend were used. Two kinds of cleaning methods were employedbefore peel test: the heat cleaning（ the SS foil was wiped with nonwoven fabric containing methyl ethyl ketonethree times → the same process with toluene was done → heated at 175 °C for 1 h → the cleaning withmethyl ethyl ketone and toluene was repeated） and the ultrasonic cleaning in toluene for 1 h. As a result, thepeel strength increased after the heat cleaning for three kinds of tapes, on the other hand, hardly increasedafter the ultrasonic cleaning. From the X-ray photoelectron spectroscopy（ XPS） analysis, the content ratioof C element on SS foil surface was high even after the cleaning process. Further, it increased by the storageat room temperature. The estimated contamination source was the lubricating oil used in the cold-rolling ofSS. It was confined in the surface concave portion during the cold-rolling process and oozing out throughsurface fine pores gradually. It was found that the heat cleaning was effective for lessening the influence ofcontamination.