The Finishing Research Of Unfigured Sea-island Polyamide Microfiber Synthetic Leather Imitate Nature Leather Technology

The filling agents and the softening agents were cross-linked to the unfigure sea-island polyamide microfiber synthetic leather base(hereafter referred to as synthetic leather base)by the appropriate crosslinking agent in this study.So as to improve the sanitary properties of the synthetic leather base and to achieve the purpose of imitate natural leather.Various types of filling agents were selected to fill synthetic leather base to improve the sanitary properties,in which zirconium tanning agent was used commonly.The softness,moisture absorption,water vapor permeability and mechanical properties of the base were used as indexes,the type and dosage of filling agent was optimized.The results indicated that the sanitary properties of the base modified by filling agent were improved generally compared with that of the blank base.Among them,the moisture absorption increased by 34%~45%,the water vapor permeability increased by 50%~56% and the mechanical properties were significantly improved.The bases before and after being filled were characterized by Fourier infrared spectroscopy(FT-IR),water contact angle,scanning electron microscopy(SEM),atomic force microscopy(AFM)and specific surface area.The results showed that the filling agent's cross-linking effect on the base fiber led to the active group content and the wettability of base increased,the fiber surface structure changed obviously and the fiber gap became larger and its dispersion was looser.Moreover,the specific surface area of the base increased.softening agents were selected to finish synthetic leather base to improve the imitate natural leather performance.By investigating the softness,moisture absorption,water vapor permeability,tensile strength and tear strength of the base before and after finishing to optimize the type and dosage of the softening agent.Compared with the base before finishing,the softness of the finishing base increased obviously,moisture absorption increased by 30%~33%,water vapor permeability increased by 48%~60%.The mechanical properties also have varying degrees of increased.The base before and after finishing were characterized by water contact angle,AFM,SEM and specific surface area.The results showed that the wettability of the finishing base was slight increased and the fiber surface microstructure changed obviously,the fiber gap became bigger,the surface area increased also.The synthetic leather base was cross-linked modified by filling agents and softening agents,in which zirconium tanning agent was as a cross-linking agent.The moisture absorption,water vapor permeability,softness and mechanical properties of the base were used as indexes.The type,dosage and compatibility process of filling agents and softening agents were optimized through the orthogonal.The experiments showed that the optimal compatibility process was achieved when using 1% Desoaten RST,5% Aluminum Tanning Agent,5% Light Color Vegetable Tannin Extract BA,10% Desopon SO,10% Clariant NLM,5% synthetic neatsfoot oil.Compared with that of blank base,the moisture absorption of the modified base increased by 37.78%,the water vapor permeability increased by 10.05%.The mechanical properties,thickening percentage and weight gain rate were obviously improved.The bases before and after modified were characterized by SEM,AFM,water contact angle and specific surface area.The results showed that the fiber of modified base arranged loosely.Its surface structure changed clearly and the wettability of base increased.Moreover,the base specific surface area increased.The filling agent and softening agent were selected to modify synthetic leather base to improve the sanitary properties.By the experiment optimization,the conditions were optimized as follows: aluminum tanning agent was the best crosslinking agent,its dosage was 25%,crosslinking temperature 40 ?,crosslinking time 2h,and p H value 2.5.Compared with that of untreated base,the moisture absorption of the base modified by crosslinking agent increased by 35.66% and the water vapor permeability increased by 53.23%.The mechanical properties were significantly improved,thickening rate and weight gain rate of the base were obvious.And modification does not affect its softness.The base before and after being crosslinked were characterized by SEM,AFM,water contact angle,specific surface area,thermal analysis(DSC-TG)and x-ray diffraction analysis(XRD).The results showed that the loose degree of the fiber increased significantly and the fiber surface structure changed obviously.The active group content and wettability of base increased.The specific surface area of the base increased and the fiber neat degree had changed.Moreover,it increased the thermal stability of the bases.The effect of washing and soaping on the sanitary properties of synthetic leather base was studied.The study showed that the sanitary property of the modified base was persistent.The water contact angle,SEM,AFM,specific surface area and x-ray photoelectron spectroscopy(XPS)of the base before and after being washing and soaping were measured.The results showed that the crosslinking modification could increase the wettability and the dispersion degree of the base.At the same time,the crosslinking modification could change the surface topography of the base,increase the hydrophilic active group of the base and the specific surface area.