Study On Water-based Natural Oil And Its Fatliquoring Performance Of Leather

At present,China has a large demand for leather fatliquors.However,the current leather products are generally at the middle and low-end levels.In terms of type and performance,it cannot meet the needs of manufacturing high-end leather production.Compared with fatliquor products in developed countries,there is still a big gap.In this study,natural animal and vegetable oils such as horse oil(HO),linseed oil(LO),and rape oil(VA)were used as raw materials,and they were modified by oxidation-phosphorylation and oxidation-maleic anhydride modification respectively,and finally six products were synthesized.The products were used as leather fatliquors and applied to sheep wet blue leather,which not only broadens the scope of application of LO and HO,but also provides a reference for the actual application of leather fatliquoring,especially for the production of high-end leather in accordance with.In this study,LO,HO and VA were used as raw materials.Firstly,the oil was epoxidized with hydrogen peroxide(H2O2),and then phosphoric acid(H3PO4)was added to reacte with it.Oxidative phosphorylated linseed oil fatliquor(P-LO),oxidative phosphorylated horse oil fatliquor(P-HO)and oxidative phosphorylated rapeseed oil fatliquor(P-VA)were synthesized.The chemical structures of epoxy products and fatliquor products were characterized by using characterization methods such as FT-IR and 1H-NMR.The emulsion stability and surface tension of the fatliquors were also measured.The reaction process was optimized by single factor and the epoxy resin was determined.The optimal synthesis conditions of oils and fats,taking the emulsion emulsification time as the index,optimized the optimal synthesis process of the oxidative phosphorylated fatliquor through single-factor experiments.The results showed that three phosphoric acid modified fatliquors were successfully prepared.When n(oil):n(H2O2):n(H3PO4)=1:2:3,the dosage of tetrabutylammonium bromide(TBAB)is 0.25 g,the reaction temperature is 120℃ and the reaction time is 3h.The fatliquor emulsion prepared under these conditions has the longest emulsification time and the best emulsification performance.P-LO,P-HO and P-VA have higher hydrophilic-lipophilic balance(HLB).The particle size of the emulsion is relatively small.The stability of the emulsion is better.Firstly,the oil was epoxidized,then maleic anhydride(MA)was added to react with it.Hydrophilic carboxylate group was introduced into the system.Oxidation maleic anhydride linseed oil fatliquor(C-LO),oxidation maleic anhydride linseed oil fatliquor(C-HO)and oxidation maleic anhydride rapeseed oil fatliquor(C-VA)were synthesized.The structure of fatliquor was determined by FT-IR.The emulsion stability and surface tension of the fatliquoring agent were also determined.The optimum synthesis conditions of oxidized maleic fat fatliquoring agent were optimized by single factor experiment.The results showed that:three kinds of maleic anhydride modified fatliquoring agents were successfully prepared.When n(oil):n(H2O2):n(MA)=1:2:3,TBAB dosage was 0.25 g,and the reaction time was 3 h at 120℃,the prepared fatliquoring agent had the best emulsifying performance and stability.The HLB values of C-LO,C-HO and C-VA are high,and the particle sizes of emulsion are small,which can be stored for a long time.The prepared P-LO,P-HO,P-VA,C-LO,C-HO,C-VA and the commercially available fatliquors P-SH and C-SH were respectively fatliquored to the crust leather.The morphological changes of leather fibers before and after fatliquoring were observed by SEM.Comparing the comprehensive effects of fatliquoring,it is found that the six synthetic fatliquors have good fatliquoring properties and can achieve P-SH and C-SH fatliquoring effects.Among them,P-HO and C-VA have the best fatliquoring performance.The results showed that the softness of fatliquored green leather was 10 mm and 9.5 mm,the thickening rate was 25.10%and 22.36%,the tensile strength was 37.65 N/mm2 and 39.28 N/mm2 and the tear strength was 52.18 N/mm and 55.12 N/mm,respectively.And it is better than the fatliquoring effect of the commercially available fatliquors P-SH and C-SH.Comprehensive comparison of the performance of the six fatliquors,C-VA has the lowest synthesis cost;C-VA and C-LO have lighter color and higher market acceptance;P-HO,P-LO and P-VA have good combination and can be widely used;P-LO,P-HO,C-LO and C-HO can be used to produce high-end leather.