Study On The Chiral Characteristics,Preparation And Performance Of Functional Materials Of Aleuritic Acid

Aleuritic acid is an important multi-hydroxy fatty acid from forest products and a significant derived compound owned high value-added and could be obtained easily.The research on developing the new uses and fields of aleuritic acid were carried out.It is of great significance to clarify the stereochemical structure and enantiomer composition of aleuritc acid.In order to innovate applied forms of aleuritic acid and to promote the structural adjustment and upgrading of the shellac industry,these efforts including prepatation mehtod in constructing functional materials and exploration of their uses were made in this thesis.Therefore,the structural characteristics of polyhydroxy fatty acids of aleuritic acid were chose as pointcut.The main works of this thesis included in three aspects,stereochemical character research and construction of chiral stationary phase,preparation and performance of PHA materials based aleuritic acid,preparation and performance of polyester type polymer brushes based aleuritic acid.It has further studied on the design and preparation of functional materials based aleuritic acid and the conclusions were mainly summarized as follows:?1?Through HPLC-ELSD method,the optimum separation condition for enantiomeric separation of aleuritic acid was obtained that built though research of series influencing factors including mobile phase composition,mobile phase ration and column temperature.DAICEL CHIRAL PAK IF?25 cm×0.46 cm i.d.,5?m?column,0.5 m L/min flow rate of mobile phase,0.1%formic acid solution?40%?:acetonitrile?60%?of mobile phase composition,30?column temperature.The parameter setting of ELSD detector was evaporator temperature70?,drift tube was kept at 60?and carrier gas?high purity nitrogen?rate was set at 1.6L/min.The results show that aleuritic acid was enantiomer of threo configuration and the content of two enantiomers were 65.5%and 34.5%,respectively.Therefore,the ee value of aleuritic acid was 31%.The results from thermal dynamic reflect that there was a good linear relation among ln?,lnk and 1/T.The difference value of enthalpy change???H?between two enantiomers was-3453.0 J/mol and difference value of entropy change???S?was-7.6776J/mol.Both of the two negative value of enthalpy and entropy change revealed that resolution process of aleuritic acid enantiomers was controlled by entropy change.?2?Based on the detection resolution method by HPLC-ELSD,the resolution condition of stereoisomerism of aleuritic acid was established by supercritical fluid chromatography?SFC?method as follows:CHIRALPAK AY-H?3.0 cm I.D.×25 cm×5?m?column,carbon dioxide and alcohol volume ratio 70:30 of mobile phase,70m L/min speed,35?column temperature,208 nm detection wavelength,77.78 mg/m L injection concentration,3 m L injection volume every time.To the two samples prepared by mentioned above SFC method,the result indicated that A and B were stereoisomers of aleuritic acid by characterization of FTIR?¹H/¹³C-NMR?DSC?TG?XRD.Furthermore,A and B samples were confirmed as enantiomers of aleuritic acid by determination of specific rotation and vibrational circular dichroism?VCD?test.According to melting point of synthetic threo and erythro aleuritic acid deteced results in previous literature,the stereochemical composition of aleuritic acid was racemate and possibly composed by 9R,10R,16-trihydroxyhexadecanoic acid and 9S,10S,16-trihydroxyhexadecanoic acid.There may be no erythro configuration in aleuritic acid obtained by saponification process.?3?Three new chiral stationary phases,CSP1,CSP2 and CSP3,were prepared successfully though a stepwise coupled reaction by taking aleuritic acid as chiral arms.The main difference of structure of CSP1,CSP2 and CSP3 was chiral selectors,containing aleuritic acid only of CSP1,introducing?S?-?+?-2-Phenylglycinol and?1R,2R?-?+?-1,2-Diphenylethylenediamine of CSP2 and CSP3,respectively.The characterization result by DSC?TG?FTIR?EA and SSNMR,the coupled reaction happened along with the design route to the three CSPs.The grafting yield of CSP1,CSP2 and CSP3 were 12.40%,78.24%and32.67%,respectively?Among the 12 compounds with different chrial centre,CSP1successfully seperated 6 enantiomers of them.The chiral separation proportion was 50%.7 compounds were separated by CSP2 and 9 compounds by CSP3 and the chiral separation proportion were 58.3%and 75%,respectively.The results indicated that aleuritic acid showed a good application prospect in the terms of charial separation materials.?4?PHAs were synthesized by a green method,melt polycondensation,using two kinds of natural hydroxy fatty acids,aleuritic acid and lactic acid,as a source of chemical raw materials.The results showed that a novel SCE-mcl-PHA was obtained via polymerization of monomers at 150°C.When the polymerization lasted for 24 h,the monomers reacted completely and the free hydroxyl group of aleuritic acid was conserved as far as possible,thereby improving the hydrophilicity of the new CS-PHA.The mcl-PHA formed by the self-polymerization of aleuritic acid achieved similar level of tensile strength in commercially available PLA and PHBV.However,the results,detected by mechanical properties and SSNMR,indicated that the main copolymerization happened between the long-chain monomers and the introduction of active small molecule,lactic acid,played a blocker by esterification on the side chain.Furthermore,increasing ratio of short-chain lactic acid monomers?5%,10%,15%,and 20%?led to the formation of SCE-mcl-PHA,rapidly adjusting their properties from rigid to soft.The properties of SCE-mcl-PHA significantly changed by adding only 5%?wt%?lactic acid monomer.Fortunately,the results of cell culture showed that both mcl-PHA and SCE-mcl-PHA obtained by melt condensation showed minimum cytotoxicity compared with microbial PHA?PLA and PHBV?.?5?The aleuritic acid based prepolymer was prepared at 120?and reaction continuing12 h.The result of MALDI-TOF showed that the molecular weight of prepolymer distributed as a arithmetic progression between the 1 to 12 and the tolerance was 286.4.The average molecular weight?Mn?was detected as 1573 by acid base titration.It means that the DPn was approximatively 5.The structure and load rate of tannin were characterized by ¹³C-NMR?FTIR?TG?DSC?EA.It was found that the grafting ratio of aleuritic acid prepolymer was higher than the grafting ratio of tannin.The increase of carbon content reached 9.74%.Because of the influence factors like steric hindrance,the rise of carbon content of grafting tannin was just 1.5%.The adsorption test showed that the adsorbing capacity of polymer brush to the 5 metal ions,Cr³⁺?Fe³⁺?Ga⁴⁺?Ge⁴⁺?In⁴⁺was 42.98 mg/g,58.13 mg/g,58.65 mg/g,36.01 mg/g,53.73 mg/g.The total adsorption achieved 249.50 mg/g.