Japanese lacquer durability

Kumanotani J 1983 Japanese lacquer - a super durable coating. Proposed structure and expanded application. In Carraker C D Jr, Sperling L H (eds) Polymer application of renewable-resource materials. Plenum Press New York, 225-248 (Polymer Sci Technol 17 225-248)... 

JAPANESE LACQUER-A SUPER DURABLE COATING (PROPOSED STRUCTURE AND EXPANDED APPLICATION)... 

What gave Japanese lacquer this durability This intigulng question launched the author on a quest which started some 25 years... 

PROOF OF DURABILITY OF JAPANESE LACQUER COATING (MEASURING DYNA-MECHANICAL PROPERTIES AGAINST STORAGE TIME)... 

Despite historically long human experience of the use of the lacquer wares, there was no scientific data evidencing the excelling durability of Japanese lacquer when we began the study of Japanese lacquer in our laboratory. 

This proved to be the first scientific data evidencing the high durability of the Japanese lacquer films, though obviously the 20 years span in this case is very short to make a comparison with an unchanging record of 1,000 years. 

Considering these findings we here propose a cell structure for the durable Japanese lacquer film the lacquer film is composed of cells or grains of 0.1 ym size packed densely in the film. The cells have plant gum wall with polymerized urushiol inside, and are firmly... 

In this cell structure model, the plant gum provides a protective barrier towards diffusion of oxygen into the polymerized urushiol inside, resulting in and explaining the high durability of Japanese lacquer films. Since the plant gum is hygroscopic, absorption of humidity would break down the barrier characteristics, and thereby causes degradation of the polymerized urushiol in the lacquer film, but a combination with hydrohobic polymerized urushiol results in a cell structure wall of low humidity absorption. 

Morphological Synthesis Assuming the aforementioned cell structure model is reasonable for durable Japanese lacquer, a morphological synthesis is one possible way to synthesize the Japanese lacquer, independent of the constituents of the sap. We thus succeeded in the preparation of reactive colloidal particle-containing alkyd resins... 

Since the petroleum crises, all renewable natural resources have been intensively sought and studied to develop urgently needed materials for the future. Since Japanese lacquer will dry at room temperatures in the presence of laccase, this Japanese lac qjer is an energy conserving coating material, an excellent characteristic which may be added to its great durability. 

In addition,considering that the super surable properties of Japanese lacquer is dependent on the cell structure made up of urushiol ( a phenolic compound) and plant gum (polysaccharides), based on this model, this cell structure in theory, generally speaking, could be expanded to improve the durability of all synthetic polymeric materials in a combination with polysaccharides which are most aboundant, being made by cultivable plants utilizing the endless resources of sun rays, water and carbon dioxide. Much research is contemplated. 

Five chapters covering oils and lacquers comprise section four. The structural changes accounting for the extraordinary durability of Japanese lacquer are described along with expanded applications. 

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