Study On The Modification And Mechanism Of Microfiber Synthetic Leather Base By Collagen

In current study, collagen extracted from leather wastes is a kind of natural material, which contains lots of active groups. Modification of microfiber synthetic leather base by collagen with proper cross-liking agent, which can improve its sanitary properties and dyeing properties, help to save resources, reduce environmental pollution and realize ultimate goal of resource utilization.Collagen was prepared by industry gelatin extracted from leather wastes by alkaline protease and was grafted onto the pretreated microfiber synthetic leather base, in which organic phosphine F-90 was used as a cross-linking agent. The contents of amino, carboxyl and formaldehyde of base were measured by inhibiting aldehyde method, Boehm titration method and acetylacetone colorimetric method. Furthermore, the surface morphology, structure, thermal properties and hydrophility of base were characterized and analyzed by SEM, FT-IR, TGA and Contact angle, respectively. The appropriate modification conditions were optimized by single factor experiment method in which the water vapor permeability and hygroscopicity were used as index. The results showed that collagen dosage was 18%, FP dosage was 9%, cross-linking modification temperature was 35℃, time was 4h and p H was 5.5. Compared with pretreated base, under the appropriate action conditions, the content of amino increased by 132.26% and the content of carboxyl increased by 187.22%, the water vapor permeability improved by 66.52%, the hygroscopicity improved by 79.31%, the tear improved by 5.65%, the tensile strength improved by 16.98% and the breaking elongation improved by 12.29%, and the content of formaldehyde in line with national standards GB/T 2912.1 2009.Microfiber synthetic leather base was modified by collagen in which the tanning F-90 was used as a cross-linking agent. The content of amino and carboxyl of base were measured by inhibiting aldehyde method and Boehm titration method. Furthermore, the base surface morphology, structure, thermal properties, hydrophility and element energy of base were characterized and analyzed by SEM, FT-IR, TGA, Contact angle, EDS and XPS, respectively. The appropriate modification conditions were optimized by single factor experiment method in which the water vapor permeability and hygroscopicity were used as index. The results showed that collagen dosage was 15%, F-90 dosage was 6%, cross-linking modification temperature was 45℃, time was 4h and p H was 7.0. Based on these, the appropriate dosage of collagen and F-90 were optimized in which the dye uptake, surface chroma and dry-rubbing and wet-rubbing fastness properties were used as index, and the results were 15% and 8%, respectively. Compared with pretreated base, under the appropriate action conditions, the content of amino and carboxyl increased by 126.21% and 186.26%, respectively. The dye uptake improved by 46.30%, the water vapor permeability improved by 65.05% and the hygroscopicity improved by 71.43%. The surface chroma deepened, the dry-rubbing and wet-rubbing fastness, the breaking elongation, the tear and tensile strength also improved.Collagen was grafted onto the microfiber synthetic leather base, and glutaraldehyde was used as a cross-linking agent. The change in dye uptake, surface chroma, and resistance to dry-rubbing and wet-rubbing fastness properties was discussed. The contents of amino, carboxyl and formaldehyde of base were measured by chemical analysis. The results indicated that the conditions by single factor experiment method were optimized as follows: collagen dosage was 15%, glutaraldehyde dosage was 8%, cross-linking modification temperature was 35℃, time was 5h and p H was 7.0. The dye uptake of modified base improved by 47.44%, the surface chroma deepened, the dyeing fastness increased, and the dry-rubbing and wet-rubbing fastness improved. Furthermore, the base were characterized by SEM-EDS、FT-IR、DSC-TGA and Contact angle respectively. The results showed that the modified base had large amount of active groups, the fiber loose degree increased and the hydrophility properties enhanced. Modification by hydrolyzed collagen also affected the thermal properties of the base.Microfiber synthetic leather base was modified by collagen, and organic phosphine FP was used as a cross-linking agent. All modified base were washed by water, acetone solution and dilute alkali solution. The way of constant weight analysis, as quantitative analysis, was used to analyze the bonding form of microfiber synthetic leather base by collagen. The mechanism of modified base was comprehensive researched according to the test results about SEM, DSC and Contact angle. The experimental results showed that when p H was 4.0 and 7.0, the binding form of microfiber synthetic leather base by collagen were as follows: the covalent bonds was the main binding form, secondly, the form of hydrogen and electrovalent bonds, finally, the physical adsorption deposition existed. In addition, p H had little effect on the binding form. Compared with the surface morphology, thermal properties and hydrophility of modified base before and after washing, it can be found that the improvements of sanitary properties and dyeing properties of microfiber synthetic leather base by collagen were lasting.