Study On Drying And Rheological Properties Of Modified Raw Lacquer

Raw lacquer,one of natural lacquer of high quality,has been applied for more than several thousand years in China.It is a kind of natural water-in-oil?W/O?type emulsion and is also an important nature resource in our country.Raw lacquer has natural and environment-friendly properties,as well as excellent physical properties such as high corrosion resistance,highly durability,antibacterial and good gloss.However,raw lacquer also has some shortcomings,such as:sensitization of raw lacquer,poor weather resistance,high drying conditions,and high viscosity of lacquer liquid and difficult construction.In this paper,for the problem of specific temperature and humidity required for the natural solidification film formation process of raw lacquer,we compound raw lacquer with quick-drying agent or improving the refining process to reduce the natural solidification film formation time of raw lacquer and to study the physical and mechanical properties and rheological properties of the modified lacquer.Provide experimental and theoretical basis for high performance and construction of raw lacquer.Using the composite method,the natural lacquer and the quick-drying agent A,B,and C were separately composited to prepare the modified quick-drying raw lacquer,and the film was cured under two drying conditions,and the physical and mechanical properties?drying performance,Adhesion,hardness?of the modified lacquer film and rheological properties?viscosity,relationship between shear stress and shear rate,non-Newtonian index n,storage modulus,loss modulus?of modified lacquer were studied.The results show that the addition of fast-drying agents A,B and C can improve the drying film formation rate of raw lacquer under two drying conditions.Among them,under the low temperature drying condition of temperature T=20?C and relative humidity R=60%,the drying rate of the quick drying agent B is increased by 88%;when the m _{quick drying agent B}:m _lacquer=10:100,the adhesion of the modified lacquer film is improved by 4levels;the hardness of all the modified lacquer films is not variety.In addition,the modified lacquer liquid is pseudoplastic fluid;under the measurement conditions of angular velocity?=6 rad/s,the viscosity of the modified lacquer m _{quick-drying agent A}:m _lacquer=8:100 and m _{quick-drying agent B}:m _lacquer=8:100 is reduced,and the viscosity of the modified lacquer of m:_{quick-drying agent C}:m _lacquer=10:100 is increased;the Newtonian of the above three modified lacquer lacquers is enhanced,both the modulus G'and the loss modulus G"change.According to the change of water content and laccase activity during the lacquer refining process,we study the effect of refining time on physical and mechanical properties?drying performance,adhesion,hardness?of the refined lacquer film and the rheological properties of the refined lacquer?viscosity,shear,stress vs shear rate,non-Newtonian index n,thixotropy,storage modulus,loss modulus?.The results show that under the dry condition of T=25? and R=85%,the dry film formation rate of refined lacquer increases,among which the refined lacquer with solid content of 72%?74%,the filming rate of solid dry drying increases 20%;the hardness and adhesion of all refined lacquer films are basically unchanged.In addition,the refined lacquer lacquers are pseudoplastic fluids;under the measurement conditions of angular velocity ?=6 rad/s,the viscosity of the refined lacquer liquid is reduced;the Newtonian properties of the refined lacquer liquid are enhanced,the thixotropy is reduced,both the modulus G'and the loss modulus G"increase,and the viscoelasticity increases.According to the different production processes of Ti Zhuang lacquer and black push lacquer?direct purchase?,we study the physical and mechanical properties?drying performance,adhesion,hardness?of Ti Zhuang lacquer and black push lacquer film and the rheological properties?viscosity,shear,stress vs shear rate,non-Newtonian index n,storage modulus,loss modulus?of Ti Zhuang lacquer and black push lacquer.The results show that under the dry condition of T=25? and R=85%,the film-forming rate of the dry-drying of Ti Zhuang lacquer is increased by 20%;the drying film-forming rate of black-painting lacquer is reduced by 10%;The hardness and adhesion of the Ti Zhuang lacquer and black push lacquer film are basically unchanged.In addition,both the Ti Zhuang lacquer and the black lacquer are pseudoplastic fluids;under the conditions of angular velocity ?=6 rad/s,the viscosity of the lacquer and the black lacquer increases;The Newtonian property is enhanced,the storage modulus G'and the loss modulus G"are both increased,and the viscoelasticity is improved.