Study On Performance Of Catalytically Modified Lacquer Wax And Lacquer-based Isopropyl Ester Microemulsion

Taxicodendron vernicifluum is one of traditional featured resources,which has a wide distribution range and a large planting area in China.Lacquer wax is a kind of oil extracted from lacquer seeds,which mainly consists of triglyceride,and has been widely utilized in the fields of daily practice chemicals,ink,high-grade cosmetics,plasticization and other fields.However,non-advanced processing technology,poor quality low melting point and dull color of lacquer wax(compared with Japanese wax)limit its fine utilization.Therefore,in this paper,methods such as catalytic hydrogenation and enzyme-catalysed esterification were used to prepare modified lacquer wax and lacquer wax based isopropyl ester(IPE).In addition,IPE microemulsion was prepared by pseudo-ternary phase diagram method,and its anti-tyrosinase activities,stability and sun protection properties were evaluated.The main results were as follows:1.Relative content of stearic acid,oleic acid and linoleic acid in the lacquer wax were acted as evaluation index,types and dosage of catalyst,pressure,reaction time and temperature were adopted as investigated factors,single factor experiment of lacquer wax hydrogenation was conducted,and stearic acid content between Japanese refined white wax and modified lacquer wax were compared.The experimental results showed that relative content of stearic acid in hydrogenated lacquer wax could reach 23.89% and iodine value of which could be reduced to 2.74mg/g,under the condition that dose of palladium carbon catalyst was 0.5%,hydrogen pressure was 0.3Mpa,reaction time was 2h,reaction temperature was 150?,and rotate speed was 500r/min.But elasticity of the hydrogenated lacquer wax decreased and easy to break because of high degree of saturation.In order to improve the performance of the hydrogenated lacquer wax,Sapium sebiferum(L.)Roxb.with high content of oleic acid and modified lacquer wax were compounded,and their hydrogenation process was researched.When the compounding ratio of hydrogenated lacquer wax and Sapium sebiferum(L.)Roxb.was 1:1,the relative content of stearic acid in the compounded wax was 17.48%,which is close to the the Japanese white wax with 17.60% of stearic acid.Meanwhile,the elasticity of compounded and hydrogenated lacquer wax was improved on account of rational ratio between oleic acid and linoleic acid.2.Single factor experiment and orthogonal experiment were used to optimize the process of transesterification of lacquer wax based isopropyl ester(IPE).Acid value of reactants were utilized as evaluation index,volume-mass ratio of isopropanol and lacquer wax,enzyme concentration,reaction temperature and time were employed as investigated factors,researching the influence of these factors on the lacquer wax enzyme-catalysed esterification.Results revealed that Novozyme 435 demonstrated the best enzyme-catalysed esterification effect.The optimal reaction condition was achieved at 10g/L of Novozyme 435,the 4:1(Isopropanol:Lacquer wax)of volume-mass ratio,140r/min of rotate speed and 36 h of reaction time at 55?.Under this condition,the acid value,viscosity and refractive index of IPE were 3.29mg/g,13.2m Pa?s and 1.441,repectively.By analyzing the GC-MS,IPE was made up of 73.64% of isopropyl palmitate,19.39% of isopropyl oleate,6.15% of isopropyl stearate and 0.82% of isopropyl linoleate.3.Lacquer wax based isopropyl ester(IPE)was used as oil phase to prepare transparent W/O microemulsions with thermodynamic stability.The pseudo-ternary phase diagram method was used to screen for optimum process of the HLB values of surfactant,cosurfactant and surfactant/cosurfactant(v/v).The type of IPE microemulsion was identified by conductivity detection and rheological properties,and prepared W/O IPE microemulsion with stable performance.The optimum formula of W/O IPE microemulsion was got by detecting its particle size and stability.The results showed that when ethanol was used as cosurfactant,Span80:Tween80=7:3 was utilized as compounding surfactant,mixed surfactant:cosurfactant = 2:1,the ratio of mixed surfactant and oil was 5:5,the low conductivity W/O IPE microemulsion was acheived.Moreover,the particle size of W/O IPE microemulsion was 20-50 nm,the solubilizing water content was 16% and the viscosity was 50 m Pa?s.4.The low conductivity W/O arbutin lacquer wax based isopropyl ester(AR-IPE)microemulsion were prepared using IPE as oil phase and 4% arbutin aqueous solution as aqueous phase.Firstly,the tyrosinase inhibition effect on the AR-IPE microemulsion was studied and the results indicated that IC50 value of AR-IPE microemulsion for tyrosinase was 1.617mg/m L.Then,ultraviolet spectrometry method was used to analyze the UV protection characteristic of IPE microemulsion,AR-IPE microemulsion and arbutin aqueous solution.The results showed that both IPE microemulsion and AR-IPE microemulsion had the ability to resist UVA and UVB.Finally,the stability of AR-IPE microemulsion was investigated by high-speed centrifugation and ultraviolet spectrophotometry.The results showed that AR-IPE microemulsion still kept clear and transparent after four weeks,and p H value and content of arbutin in which had a little variation.Therefore,AR-IPE microemulsion can be used as an new and effective whitening sunscreen preparation.