Synthesis And Properties Of Terpinene-based Surfactant And Adsorbent Resins

As a natural organic compound and renewable biomass resource,α-terpinene has an extensive use because a variety of chemicals and materials could be derived from it,which realizes its high value and contributes to the green development in our country.Three surfactants including tertiary amine N-oxide（TAO）,tertiary amine N-benzyl chloride（TABC）and tertiary amine N-methyl iodide（TAMI）were synthesized by Diels-Alder reaction from tertiary amine（TA）who is a derivative ofα-pinene.Their structures were characterized and their surface properties and bacteriostatic ability were investigated.Tests found that the critical micelle concentration（CMC）of TAO,TABC and TAMI are 3.39×10^-3,2.46×10^-3 and 2.37×10^-3 mol/L,and their surface tension(γ_CMC)are 33.0,25.2 and 26.4 m N/m,respectively,all are better than the commercial surfactant that is dodecyl dimethyl benzyl ammonium chloride（DDBAC）.The emulsifying time of TAO（528 s）,TABC（341.7 s）and TAMI（271 s）are enough long for them to have a good emulsification ability.Except for TAO,both TABC and TAMI have a good foaming performance and foam stability with the foaming height of 76.62mm and 87.77 mm,and the foaming stability of 0.85 and 0.87,respectively.In addition,TABC and TAMI perform well in calcium hard water stability test,while TAO is unstable.The result of contact angle experiments showed that all three surfactants could improve the wetting ability of water on organic and inorganic materials.Furthermore,TABC shows the best bacteriostatic effect on Staphylococcus aureus,with 21 mm in the diameter of bacteriostatic zone and 99.99%in the bacteriostatic rates.Adsorbents that rosin-based surfactants loaded on zeolite,kaolin and other carriers could effectively remove micro-pollutants from water.A key problem for their application is that their adsorbed active molecules on carrier readily loss in the water treatment process,which makes it a poor performance in regeneration and recycling.This problem can be uprooted by grafting surfactant molecules onto cross-linked resins.Accordingly,the cross-linking agent（TF）was synthesized by Diels-Alder reaction from the intermediate who is an esterifying and chlorinating derivative ofα-pinene.As a precursor,the polymer of tertiary amine（PTA）was prepared by suspension polymerization from 2-（Dimethylamino）ethyl methacrylate and TF.And the PTA was modified with iodomethane to obtain the polymer of quaternary ammonium iodide（PQAI）,with benzyl chloride to obtain the polymer of quaternary ammonium chloride（PQAC）,and with hydrogen peroxide to obtain the polymer of tertiary amine oxide（PTAO）.Then,the polymer of quaternary ammonium acetate（PQAA）was derived from the reaction of the PQAI and CH₃COOH.Their physicochemical structures were characterized by the Fourier Transform Infrared（FTIR）,the Scanning Electron Microscope（SEM）,and the isotherm nitrogen adsorption and desorption of Brunauer,Emmett and Teller（BET）.And their thermal stability were tested by thermogravimetry（TG）.Their adsorption performance for As（V）and methyl orange（MO）was evaluated by a batch preliminary experiments,which found that the PQAC had the best adsorption capacity on As（V）and MO,with their maximum adsorption amounts of 104.86 mg/g and 909.23 mg/g,respectively.Hence a detailed investigation was performed on the adsorption of PQAC for As（V）and MO in water,in which various factors on the adsorption property,such as initial concentration of solution,adsorbent dose,adsorption time,p H value,were assessed.The adsorption process was analyzed by adsorption kinetics,thermodynamics and equilibrium isotherms,as well as their reusability and regeneration performance.Finally,the adsorption mechanism of PQAC was proposed by FTIR and XPS.Tests found that the PQAC shows good removal performance for As（V）and MO with the theoretical maximum adsorption capacities of 116.21mg/g and 943.73 mg/g,respectively.The variational p H value has an impact on the adsorption of PQAC because the presence form of pollutant ions relies on the p H value,and the protonation degree of PQAC as well.The PQAC adsorption process of As（V）and MO conforms to the Langmuir isothermal adsorption model（R²>0.99 and R²>0.97）and the proposed secondary kinetics（R²>0.99 and R²>0.99）,indicating that the adsorption process is influenced by chemisorption mechanism and ion exchange.Further analysis of FTIR and XPS demonstrated that the nitrogen of quaternary ammonium is the most important site of PQAC for the adsorption of As（V）and MO.