| Nonionic polymer surfactants, which possess the power to absorb on the in terface of solution and behave many capabilities including emulsification,forming film, improving viscosity, flocculation, dispersion and solubilization, had been widely used in different fields including food, medicine, petroleum, chemical, de tergent, textiles, cosmetics and others. The preparation of glycidyl dehydroabiety ate (DHAGE), allyl dehydroabietyate (DHAAE) and the polymeric nonionic. surf actants including glycidyl dehydroabietyate grafted chitooligosaccharide (DHAGE-g-LMWCTS) and allyl dehydroabietyate grafted chitooligosaccharide (DHAAE-g-LMWCTS) were studied. Meanwhile, the surface activities, emulsifying power a nd foaming abilities of DHAGE-g-LMWCTS and DHAAE-g-LMWCTS had also been investigated..Dehydroabietic acid was isolated from disproportionated rosin using method of salt formation with ethanolamine as reactant. DHAGE was prepared through condensation reaction between sodium dehydroabietate,(DHA-Na) and epichloroh ydrin (ECH), and the effects of solvent type, catalyst type, reaction time, reacti on temperature and mass ratio of reactants on the yield of DHAGE were invest igated. The structure of product was characterized by FT-IR, GC-MS and 1H N MR, and the content of DHAGE in the product was determined by measuring t he epoxy value. Experimental results indicated the suitable condition for prepari ng the DHAGE was as following:xylene was utilized as solvent, tetrabutyl am monium bromide (TBAB) was as catalyst, reaction time was 4.0 h, reaction tern perature was 95℃ and the mass ratio of ECH versus sodium dehydroabietate was 4.0:1.0, and the yield of DHAGE was 83.1% under this condition.DHAAE was synthesized using acyl chloride and DHA-Na respectively. Th e experimental result of acyl chloride method was as follows:using dichlorometh ane as solvent,pyridine as deacid reagent,TEMPO as polymerization inhibitor,reac tion time was 5.0h,reaction temperature was 50℃ and the mole ratio of allyl al cohol versus dehydroabietic acid chloride was 1.0:1.0,and the yield of DHAAE was 82.0% under this condition.That of DHA-Na method was as follows:DMF was utilized as solvent, CTAB was as catalyst, reaction time was 7.0h,reaction t emperature was 45℃ and the mass ratio of allyl chloride versus sodium dehydr oabietate was 2.5:1.0, and the yield of DHAGE was 55.0% under this condition. The structure of DHAAE was characterized by FT-IR, GC-MS and 1H NMRA series of water-soluble chitooligosaccharide (LMWCTS) with different mo lecular weight was obtained through oxidative degradation of chitosan (CTS) wit h sodium nitrite as oxidant under different conditions. The DHAGE-g-LMWCTS was obtained through the reaction between DHAGE and LMWCTS, and the D HAAE-g-LMWCTS was obtained through the reaction between DHAAE and L MWCTS, respectively. The FT-IR and 1H NMR were utilized to characterize th e structure of products, and the grafting degree of polymeric nonionic surfactant s were determinated by gravimetric analysis, the surface tensions of solution co ncerned withpolymeric surfactants were measured by Du Nouy ring method, the emulsifying power concerned with polymeric surfactant was evaluated with tolu ene as model oil, and the foaming capabilities of DHAGE-g-LMWCTS and DH AAE-g-LMWCTS were investigated using oscillametric method.Experimental results of surface activities indicated the γcmc was decreased w ith the decrease of molecular weight of LMWCTS for DHAGE-g-LMWCTSs w hen the substituting degree was similar with each other. The critical micelle con centration (CMC) and γcmc of DHAGE-g-LMWCTSs, which substituting degree was 17.0% and the molecular weight of LMWCTS was 10814, were 1.5g/L and 52.47mN/m in aqueous solution, respectively. When the molecular weight of L MWCTS was 20879, the γcmc of DHAGE-g-LMWCTS was decreased with the i ncrease of its substituting degree, and CMC and ycmc of DHAGE-g-LMWCTS, which substituting degree was 28.0%, were 2.0g/L and 51.88mN/m in aqueous s olution, respectively.Experimental results of surface activities indicated the γcmc was decreased fir stly and then increased with the decrease of molecular weight of LMWCTS for DHAAE-g-LMWCTSs in aqueous solution when the substituting degree was si milar with each other. The CMC and γcmc of DHAAE-g-LMWCTS, which subst ituting degree was 20.5% and the molecular weight of LMWCTS was 24600, w ere 0.5g/L and 51.22mN/m in aqueous solution, respectively. When the molecula r weight of LMWCTS was 27357, the ycmc of DHAAE-g-LMWCTS was decrea sed with the increase of its substituting degree, and CMC and γcmc of DHAAE- g-LMWCTS, which substituting degree was 19.0%, were 2.0g/L and 51.99 mN /m in aqueous solution, respectively.Experimental results of emulsification and forming foam indicated the stabil ization times of emulsion of toluene were 211s,228s,14s,14s,114s and 52s when DHAGE-g-LMWCTS (its substituting degree was 19.5% and the molecul ar weight of LMWCTS was 27357), DHAAE-g-LMWCTS (its substituting degre e was 11.0% and the molecular weight of LMWCTS was 20879), LMWCTS (it s molecular weight was 27357),monoglyceride, sucrose esters and Span-80 wer e utilized as emulsifier, respectively. The initial heights of foam for theses surfa ctant were 16mm,18.3mm,0,0,0 and 6.0 mm when the mass concentration is 0.5g/100ml,respectively.All these results indicated the emulsifying power and th e capability for forming foam of DHAGE-g-LMWCTS and DHAAE-g-LMWCT S were superior to that of monoglyceride, sucrose esters and Span-80. |
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