A study of the Chinese organic–inorganic hybrid sealing material used in “Huaguang No.1” ancient wooden ship

Chu-nam putty is a special organic–inorganic hybrid material invented by ancient Chinese people. It was prepared by mixing tung-oil, lime and oakum (plant fibers like jute, ramie and so on) with excellent sealing performance. The invention and application of Chu-nam putty in wooden ship lead to improvement in sailing technology and ship safety issue. In this paper, the analytical results of a piece of chu-nam putty which was discovered in “Huaguang No.1” ancient ship are presented. The results show that the components of chu-nam putty are calcite, carboxylate and unsaturated esters by means of FT-IR, XRD and TGA/DSC. And the FT-IR and cross-section microscopic analysis confirm that the oakum was from jute. Comparing with the modeling putty samples it is found that the outstanding sealing performance of chu-nam putty comes from the coordination reaction of Ca2+ from the Ca(OH)2 and the oxidation aggregation reaction of Cdouble bond; length as m-dashC double bonds in unsaturated fatty acid.