Research Of Alkyl Polyglucoside Derivative/Ag-TiO₂/Soybean Phospholipids Nanocomposite Fatliquor

Fatliquor is one of the most widely used leather chemicals in leather industry.With increasing environmental concerns,vegetable oil-based chemicals are drawing more and more attention.Soybean phospholipids fatliquor has good electrolyte-resistance stability,it can also combine with Cr³⁺of wet-blue leather to enhance softness,fullness and waterproofing property of leather.Soybean phospholipids fatliquor and its fatliquored leather are easy to be attacked by mold because of the presence of unsaturated bonds and free fatty acids.In this thesis,soybean phospholipids were used to prepare fatliquor,and the soybean phospholipids fatliquor can form multi-point combination with collagen fibers.Then,organic antimold material and inorganic antimold material were added into soybean phospholipids fatliquor to improve its antimold ability.The nanocomposite fatliquor with good antimold ability was obtained by synergistic antimold effect of the natural antimold material and nano antimold material.The nanocomposite fatliquor was subsequently applied in fatliquoring process.Leather treated with nanocomposite fatliquor exhibited good antimold ability.The detailed research contents and major results are listed as following:?1?Soybean phospholipids fatliquor was prepared by terminal amino reaction,oxidation,and sulfite,respectively.The preparation process was optimized by investigating the usage ratios of raw materials,reaction time,and reaction temperature.The FT-IR result showed that the soybean phospholipids fatliquor was successfully prepared.TEM and DLS results showed that different aggregates gathered by self-assembling of micelles in the fatliquor with the increasing of soybean phospholipids fatliquor dosage.When the dosage of soybean phospholipids fatliquor was 8%,the micelle within fatliquor emulsion exhibited a single spherical structure with an average size of 170 nm,which is benefit to its penetration and dispersion into collagen fibers.The results of emulsion stability test showed that the prepared soybean phospholipids fatliquor had good dilution stability,electrolyte-resistance stability,and emulsifying property.The fatliquor was applied in fatliquoring process of goat upper leather.When the dosage of soybean phospholipids fatliquor was 8%,the softness and physical and mechanical properties of leather treated with soybean phospholipids fatliquor were close to those of the commercial fatliquor when its dosage was12%.The biodegradability results showed that the soybean phospholipids fatliquor had good biodegradability.Soybean phospholipids fatliquor can form combination with collagen fibers in different ways.Zeta potential,UV-Vis spectra and 2D IR spectra results showed that multi-point combination can be formed between phosphoric and sulfonic groups of soybean phospholipids fatliquor,including ionic bonds,coordination bonds and hydrogen bonds.?2?Alkyl glycoside derivatives?APGD?was obtained from alkyl glycoside?APG?,including alkyl glycoside sulfate?APGS?and alkyl glycoside sulfosuccinate?APGSS?,and the preparation processes were optimized.The longer the APGD alkyl chain was,the better antimold property of APGD was.C_12-14 alkyl glycoside sulfate?APGS1214?and C_12-14 alkyl glycoside sulfosuccinate?APGSS1214?had good antimold ability.The antimold ability of APGSS was better than APGS with same alkyl chain length.The APGD/soybean phospholipids composite fatliquors were prepared by introducing APGS1214 and APGSS1214 into the soybean phospholipids fatliquor.The APGD/soybean phospholipids composite fatliquor had good dilution stability and anti-electrolyte stability.The application results showed that the leather treated with APGSS1214/soybean phospholipids fatliquor had better comprehensive performance,comparing with APGS1214/soybean phospholipids fatliquor.When the dosage of APGSS1214 was 6%,the softness of leather was 8.85 mm,the tensile strength was 21.36 MPa,the elongation break was 74.4%,and the tear strength was 48.9N/mm.Moreover,the fatliquored leather exhibited good antimold ability.The inhibition zone of leather treated with APGSS1214/soybean phospholipids fatliquor was 1.2 mm for Aspergillus niger.Therefore,6%APGSS1214/soybean phospholipids composite fatliquor was selected as the alkyl glycoside derivative?APGD?/soybean phospholipids composite fatliquor in the following chapters.?3?The anatase TiO₂ nanoparticles were prepared using sol-gel method.The effects of butyl titanate concentration and reaction temperature on the morphology,size and crystal morphology of nano-TiO₂ were investigated and optimized.The optimization results showed that the mole ratio between tetrabutyl titanate and glycol was 0.90:50,the reaction temperature was 25?,and the reaction time was 8 h.When the mole ratio of tetrabutyl titanate and acetone was 1:100,spherical anatase TiO₂ nanoparticles with a dimater of 50?80 nm were prepared.Moreover,APGSS1214 was used to modify anatase TiO₂,and then introducing into APGD/soybean phospholipids composite fatliquor to prepare APGD/TiO₂/soybean phospholipids nanocomposite fatliquor.The results showed that nanocomposite fatliquor had good emulsion stability and antimold ability.The antimold ability was increased with the increasing of the dosage of TiO₂ nanoparticles.The application results showed that the softness remained unchanged with introduction of modified TiO₂.When the dosage of TiO₂ was 6%,the tensile strength of leather fatliquored with APGD/TiO₂/soybean phospholipids nanocomposite fatliquor was 25.3 MPa,the elongation break was98.9%,the tear strength was 77.0 N/mm,and the leather exhibited good antimold ability for Aspergillus flavus with 3.0 mm inhibition zone,and Aspergillus niger with 11.5 mm inhibition zone.?4?In order to further enhance the antimold ability of nanocomposite fatliquor,Ag was introduced to coat on the surface of the TiO₂ nanoparticles.The effects of raw material ratio and reaction time on the morphology,size and UV absorbance of nano Ag were systematically investigated.The results showed that when the mole ratio of AgNO₃ and NaBH₄ was 1:3,the reaction time was120 min,the Ag-TiO₂ nanocomposite particles exhibited better photocatalytic ability.APGD/Ag-TiO₂/soybean phospholipid nanocomposite fatliquor was then prepared by simple physical blending method.The DLS results showed that the particle size of APGD/Ag-TiO₂/soybean phospholipid nanocomposite fatliquor was higher than that of the APGD/TiO₂/soybean phospholipid nanocomposite fatliquor.And the effect of Ag loading on the particle size of APGD/Ag-TiO₂/soybean phospholipid nanocomposite fatliquor is not obvious.The antimold ability of APGD/Ag-TiO₂/soybean phospholipid nanocomposite fatliquor increased with the increasing of Ag loading.When the Ag loading was2.5%,the APGD/Ag-TiO₂/soybean phospholipids nanocomposite fatliquor exhibited good antimold ability,and the inhibition zone for Aspergillus flavus and Aspergillus niger was 11.5 mm and 20.2 mm,respectively.The application results showed that the introduction of Ag has no significant effect on the softness of leather,but it has a certain effect on the physical and mechanical properties of leather.When the dosage of Ag was 2.5%,the leather showed better antimold ability on Aspergillus flavus and Aspergillus niger,and the inhibition zone size was 21.4 mm and 21.5 mm,respectively.?5?The penetration and dispersion mechanism of APGD/Ag-TiO₂/soybean phospholipids nanocomposite fatliquor in collagen fibers were investigated,and its combination mechanism with collagen fibers was explored.The penetration and dispersion mechanism of APGD/Ag-TiO₂/soybean phospholipid nanocomposite fatliquor were investigated by TEM,DLS and emulsion properties of nanocomposite fatliquor.The SEM and EDS characterizations of the fatliquored leather were carried out to study the effect of the looseness of collagen fibers of fatliquored leather,and the distribution of the nanoparticle in collagen fibers on the dispersibility of nanocomposite fatliquor.The penetration and dispersion mechanism of the APGD/Ag-TiO₂/soybean phospholipid nanocomposite fatliquor were obtained:nanocomposite fatliquor with spherical micelle structure penetrates from the pores and the fiber gap into the interior of the fiber,uniformly dispersed between the collagen fibers,and then deposited on the surface of the collagen fibers to form a discontinuous composite oil film.The interfacial effect between APGD/Ag-TiO₂/soybean phospholipids nanocomposite fatliquor and collagen fibers was investigated by Zeta potential,UV-Vis spectra,2D IR spectra and molecular dynamics analysis.The results showed that the the nanocompsite fatliquor and collagen fibers formed a multi-point combinatin,including ionic bond,hydrogen bond,coordination bond and Van der Waals force.The ionic bond,coordination bond and hydrogen bond were mainly existed between soybean phospholipids nanocomposite fatliquor and collagen fibers,including.The ionic bond and hydrogen bond were mainly existed between alkyl polyglucoside derivative and collagen fibers.Hydrogen bond was mainly existed between nano TiO₂ and collagen fibers.Van der Waals interaction was mainly formed between nano Ag and collagen fibers.