Study Of Interpenetrating Polymer Networks Based On Raw Lacquer

Interpenetrating polymer networks (IPN's)based on raw lacquer were prepared in the present work. The properties and the film-forming performances of the IPN's coating were also studied. Firstly, the lacquer sap should be stired at room temperature in order to decrease the water phase fraction . At that time, aerobic oxidation of urushiol takes place. So that, the lacquer sap can be blended with the resin easily. Raw lacquer/multihydroxyl polyacrylate resin, raw lacquer/acrylic-silicon resin, raw lacquer/polymer of cardanol formaldehyde diethylenetriamine (RL/PCD) IPN's were synthesized. Secondly,the reaction mechanism of the raw lacquer and isocyanates was proposed. Results show, adding isocyanates as the third components of the IPN's could effectively improve their compatibility, and enhance the interation between the components then reduce the drying time of the coating.The proper proportions between raw lacquer and resins were got by the physico-mechanical properties test. Scanning electron microscopy (SEM) shows that just the same as the sap of lacquer, the IPN's emusion are water in oil type. The glass transition temperatures (T_g) of the IPN film are reduced because of the linear resin. Adding isocyanates as the third components of the IPN has improved the compatibility and interpenetrating extent of IPN's and increased the glass transition temperatures. The weather stability and heat-resistant of the films are also perfected. Besides, RL/PCD films exhibit both chemical resistance and weather resistance.Results show that the preparation of IPN's make use of all the components of raw lacquer. With outsthanding physico-mechanical properties and chemical resistance, the result IPN films exhibit weather stability. Therefore, IPN technology is useful to develop the natural production, especially the Chinese lacquer, and it may also provide a reliable theoretical basis for the study and research on new material.