In order to create a sustainable society, the recycling of polymeric materials is an extremely significantproblem to be solved. Polyurethanes are industrially important polymeric materials, and their recycling intoraw chemicals is extensively reported. In this review, the development of thermal and chemical recyclingmethodologies is described, with a focus on the novel chemical recycling of polyurethanes by hydrolysisreactions.Recently, we found a carbonic acid-catalysed hydrolytic system for polyurethanes. In this reaction,pressurised CO₂ is loaded into a mixture of polyurethane and water. The CO₂ dissolves in water to formcarbonic acid that functions as an acid catalyst for the hydrolysis. After the reaction is complete, CO₂ iseasily removed from the reaction system by venting the vessel. The hydrolysis reaction affords raw chemicals（diamine and alcohol） from polyurethanes in high yields with high purity and selectivity. The hydrolysisbehaviour is dependent on the chemical structure of the polyurethanes, and the reaction conditions such asthe CO₂ pressure.The reaction conditions in our system are relatively mild compared to those in a similar system in waterwithout CO₂. Moreover, strong-acid or strong-base catalysts are not required, thus removing the needto neutralise the reaction mixture and isolate the reaction products. CO₂ is abundant, cheap, minimallyhazardous, non-flammable, easily available, and easily removable. Therefore, this hydrolysis of polyurethanewith CO₂ is an environmentally friendly chemical-reaction-based method.

Various kinds of applications using water-soluble polymers were introduced in this review. pH-responsiveunimer micelles were prepared via conventional random copolymerization. The random copolymer formedunimer micelles at acidic condition, while it expanded at basic conditions due to electrostatic repulsion of thependant anions. Also pH-responsive diblock copolymers were prepared via controlled radical polymerization.The diblock copolymer dissolved as a unimer state in basic water, while it formed micelles in acidic conditions.To prepare inorganic metal oxide hollow nanoparticles, we used a water-soluble ABC type triblock copolymer.The polymer micelle formed from the triblock copolymers can be used as a template, which was decomposedby calcination to prepare inorganic hollow nanoparticles. Oppositely charged diblock copolymers containingwater-soluble nonionic block can form water-soluble polyion complex（ PIC） micelles and vesicles. Controlledradical polymerization is powerful tool to prepare new designed water-soluble polymers.

一液性湿気硬化型シアノアクリレート接着剤の接着強度の向上について検討した。単純重ね合せ継手を用いて，接着剤が硬化した後，加熱を行い，加熱温度及び加熱時間が接着強度に及ぼす影響について調べた。さらに，加熱によって変色した破断面の表面色を定量的に測定し，接着強度との関係について調べた。被着体は一般構造用圧延鋼材SS400 とし，接着面の表面性状を一定とした。接着時と硬化時の湿度は一定とし，十分接着剤が硬化した後，加熱した。その結果，常温で硬化した後，加熱を行うことで接着強度は上昇する傾向が見られた。しかし，加熱時の温度が高すぎる場合，接着強度は低下する傾向が見られた。また，破断面の表面色を測定することで接着継手のおおよその強度が予測可能であることを示した。

3-グリシドキシプロピルトリメトキシシラン（ GPTMS） でシリカ粒子の表面処理を行い，その熱重量（TG） 分析による重量減少カーブから処理層のキャラクタリゼーションを検討した。このために，アルコール洗浄前後の処理粒子，モノマー状GPTMS やGPTMS のオリゴマーのTG カーブを比較した。処理粒子のTG カーブは，3 段階の重量減少を示した。アルコール洗浄後の処理粒子とオリゴマーのTG カーブは，第3 段のみであった。表面処理粒子のTG カーブの各段の成分は，以下であると考えた。第1 段は物理吸着GPTMS 分子の蒸発，第3 段は，化学吸着と物理吸着のオリゴマー，および化学吸着したGPTMS 分子である。第2 段は，表面と水素結合を形成したGPTMS 分子と推定した。アルコール洗浄前後のTG カーブの比較は，処理層のキャラクタリゼーションに有用であることが分った。

To obtain organic-inorganic hybrid materials, control of interface between the organic and the inorganic phases is critically important. In the major cases, the surface of inorganic particles are modified by organic functional groups to make the particles miscible to the organic materials. The formation methods for organicinorganic hybrid materials according to this approach are widely investigated. Alternatively, there can be an approach that modifies the surface of organic phase to be compatible with inorganic phase. We have been investigating the formation of organic-inorganic hybrid materials via the latter approach. In this review, our resent results concerning the electrodeposition and electroless plating of inorganic materials onto the modified organic surfaces are shown. The electrodeposition of metal oxide onto the polymer particle adsorbed electrode revealed that the metal oxide deposition prefers the anionic polymer particle surface. Also, the electrodeposition of metal oxide onto the layer-by-layer（LbL）treated electrode showed that the charged surface can control the crystal orientation of the metal oxide and layered metal hydroxide. The LbL treatment can be applied to the metal electroless plating onto PET and PEN film. It revealed that the charge of the organic surface plays an important role to direct the selective nucleation onto the organic surface and thus obtained nuclear induces the formation of various inorganic materials.