The organic solvents included in paints are harmful to the human and environment. Therefore, alternative paint using water as a solvent has attracted a lot of attention. However, there remains technical issue in both of solubility of resins and water resistant of the coated film. We focused on poly(N-methylolacrylamide), the N-methylol groups of which react each other and lose hydrophilic hydroxyl groups due to self-condensation by heating. We revealed that the polymer was soluble in water while the cured one was not soluble in water. Moreover, the coated film containing a silane coupling agent remained intact in water even after 24 h.

Macroporous organic－inorganic polymer hybrids were prepared from polyvinyl pyrrolidone, and inorganic alkoxides in the presence of extract from used tea leaves. To a reaction mixture of polyvinyl pyrrolidone and tetramethoxysilane, extract from used tea leaves and HCl aqueous solution in methanol were added. The resulting mixture was constantly stirred at room temperature for 1 h and heated and dried at 60 ℃ for 2 weeks. When the tea extract was used, the turbid polymer hybrids were obtained. In the SEM image of the obtained polymer hybrids, spherical pores were observed. The corresponding polymer hybrids were a macroporous material having a pore size from 7.57 to 18.49 μm. Therefore, we succeeded in finding that the used tea leafs were able to utilize for the synthesis of novel macroporous materials.

Lowering of water absorption for epoxy resin by the addition of silica particle and silane coupling agent (SCA) was investigated. The water absorption decreased with the increase of silica content. Bonding, hydrocarbon, and fluorocarbon type SCAs were employed. The bonding type has glycidoxy or amino groups that react with epoxy resin, whereas the other types have only hydrophobic chains. The water absorption was lower for the hydrocarbon type than the bonding type. The fluorocarbon type SCA was also effective at zero and low silica content. Modification of the epoxy phase by SCA addition had a more dominant effect than interfacial adhesion for the lowering of water absorption, whereas it had been conventionally considered that interfacial adhesion had a more dominant effect. Two addition methods were compared, a pre-treatment method and an integral blend method in which all components were mixed simultaneously. The integral blend method was found to be superior to the pre-treatment method for water absorption contrary to the conventional view.

The solid catalyst coated sand is coated with meta-xylene sulfonic acid, and the catalytic action causes cross-linking by the methylene bond of the methylol groups of the furfuryl alcohol, etc. , and growth into a three dimensional network structure. At this time, large amounts of water are produced. If the water can be discharged effectively, the reaction rate is also improved. Anhydrous magnesium sulfate changes the state of water generated during the reaction into magnesium sulfate hydrate by hydration. This hydration is very fast, resulting in the dramatic increase in the hardening rate of the binder, which contributes the improvement of the dimensional accuracy of the mold and realizes ultra-high performance 3D laminated molding mold.

With the variety of porous polymers developed to date, the first half of this review aims to provide an overview of five types of porous supramolecular networks. that offer the opportunity of self-assembled 2D/3D nanostructures; Metal organic framework (MOF), Hydrogen-bonded framework (HOF), Porous organic polymer (POP) and Porous organic cages (POC). While porosity of MOF, HOF and COF networks, can be achieved by using reversible metal coordination bond, hydrogen bond and covalent bond, POP and POC are made by introduction of space-controlled groups and intrinsic porosity. The latter half of this review provides an overview of silicates, polysilsesqueoxane and silicone that have potential for extending MOF and POP networks to them. The HOF and COF networks of silanol and silanepolycathecolate extended very recently are also explained.