Study Of Modification And Weatherability Of Raw Lacquer

Raw lacquer,one of natural products of high quality,has been applied for more than 7000 years in our country,which can form film of hard wearing,bright and super dur-ability.However,law lacquer has some disadvantages in its application,such as,it is not easy to paint due to its high viscosity;it need specific curing conditions;it presents poor resistance to weather.In this paper,some basic researches have been done to explore how to improve lacquer film's weather resistance.The lacquer(Laccase is active and coating can be solidified into film)is the main object in the study.According to lacquer's morphology and its film-forming mechanism,traditional refining technology and spontaneous curing method were used to make raw lacquer/tung oil mixture films.Then,the effects on photooxidation aging property of acrylic resin and light stabilizers(UV351,UV770,nano Ti02 and nano Si02)to raw lacquer/tung oil mixture films were studied.The mixture films' structure were confirmed by FT-IR,SEM and XPS.Through the experiments of natural aging,artificial accelerated aging and the tests of water contact angle,TG,DMA,conventional physical properties and the mixture films' properties were analyzed.In terms of old lacquer(called dead lacquer),the film was formed by thermal polymerization and adding curing agent to urushiol extracted from dead lacquer.The light resistance and oxygen aging properties of dead lacquer/tung oil mixture films and urushiol polyurethane composite films were studied,Then,the effects on photooxidation aging property of light stabilizers(UV531?UV770 and Nano titania)and montmorillonite to dead lacquer/tung oil mixture films were studied.The mixture films' structure were confirmed by similar characterization method.The results show that tung oil,acrylic resin,light stabilizers UV531and light stabilizers UV770 can all improve the weather resistance of lacquer film,among which UV770 presents best.We also found that the use of tung oil,synthetic resin and light stabilizers fully activates the components of lacquer,which enables the mixture films to keep the original excellent performances of lacquer films.The researches may broaden raw lacquer's application and provide theory evidence for its development.