| Fatty alcohol phosphate is one of the most important leather chemicals on the market.Gemini fatty alcohol phosphate surfactant has also been concerned.This kind of fine chemicals has been widely used in leather wet processing because of its multi-functional and combined effect.At present,the research focus is mainly on fatliquoring process of chrome tanned leather.In this paper,series Gemini fatty alcohol phosphate surfactants linked with polyethylene glycol were synthesized by using POCl3 as phosphorylation reagent,and the basic physicochemical properties of the products were studied.The products were applied to fat-liquoring process of sheep chrome tanned leather.The effects of alkyl chain and spacer chain length on leather fat-liquoring was discussed.The aim was to clarify the relationship between product structure and leather fat-liquoring,and provide theoretical basis for the development and application of Gemini phosphate leather chemicals.In this project,firstly,polyethylene glycol(PEG-400,PEG-600,PEG-800 and PEG-1000)and POCl3 were used for phosphorylation reaction,and then N-fatty alcohol(octanol,dodecanol,hexadecanol,octadecanol)was added for esterification reaction.Finally,four series of Gemini fatty alcohol phosphate surfactants(abbreviated as m-400,m-600,m-800,m-1000,m=8,12,16,18)were synthesized by hydrolysis and neutralization.The experimental results showed that the suitable temperature for phosphorylation reaction was 5?,the reaction time was 6 h,n(POCl3):n(PEG)=2:1;the appropriate temperature for esterification reaction was 30?,the reaction time was 4 h,n(POCl3):n(fatty alcohol)=1:1.The product was purified by recrystallization,and the product structure was characterized by infrared spectrum(FT-IR)and hydrogen nuclear magnetic resonance spectrum(1H-NMR),which proved that the target product formed by the reaction was consistent with the expected result.The effects of alkyl carbon chain and spacer chain length on the basic surface active properties of the products were studied by evaluating the emulsifying power,emulsion stability,particle size,surface activity,wettability,foaming and aggregation properties.The results showed that the physicochemical properties of the products with an alkyl carbon number of 8 were good.With an increase of alkyl carbon chain,the particle size and surface tension of the series products were increased,and the emulsifying properties,wettability and foam stability were decreased.With an increase of the spacer chain,the micelles formed by these Gemini surfactant solutions showed an increasing trend from linear to vesicle,ellipsoid and sphere.The surface tension was decreased,emulsification,wettability and foam stability were all improved.The surface tension of m-800(m=8)could be reduced to 26.3 mN/m.Series Gemini phosphate surfactants were used in fat-liquoring process of sheepskin chrome tanned leather.The effects of product structure on softness,mechanical strength,hydrophobicity,hygienic and antistatic properties of the fat-liquored leather were discussed.The results showed that with an increase of alkyl carbon chain,the softness,hydrophobicity and mechanical strength of fat-liquored leather were increased gradually.The fatliquoring performance of the products with carbon number of 16 were fine.With an increase of the spacer chain,the softness,hydrophobicity,mechanical strength and the vapor permeability of fat-liquored leather were decreased,and the antistatic property was increased gradually.In conclusion,the leather fat-liquored performance of m-400(m=16)was good,the softness,tensile strength and tear strength of fat-liquored leather were 9.84 mm,39.97 N/mm2,and 47.14 N/mm,respectively.Microscopic analysis showed that the leather fibers were loose and the fiber bundles were arranged regularly.The leather properties of 16-400 Gemini phosphate fatliquor compounded with mineral oil were further improved. |
PDF Full Text Request