Compared to natural leather, microfiber synthetic leather has many excellent qualities, such as chemical resistance and physical and mechanical properties. However, preparation of microfiber synthetic leather with a high water vapor transmission rate (WVT), moisture absorption and wearing comfort property is still a challenge. In this study, we prepared thermoplastic polyurethane (TPU)/sulfonated polysulfone (SPSf) electrospun nanofibers and applied them to a microfiber synthetic leather base (MSLB). The effects of TPU/SPSf nanofiber content on the structure and properties of the MSLB were investigated. The results indicated that the TPU/SPSf nanofibers with an average diameter of 0.12 µm were well distributed at all directions in the MSLB. Differential scanning calorimetry analysis showed four Tg peaks, further demonstrating the existence of TPU/SPSf nanofibers. With the increase of TPU/SPSf nanofiber content from 0 to 30 wt%, the contact angles decreased gradually from 111.64° to 67.07°, leading to 55.19% improvement in the WVT value (from 2868.96 to 4452.24 g/(m2•24 h)) and 26.25% improvement in the moisture absorption (from 628.70% to 793.75% mm/s). Simultaneously, when the nanofiber content was 30 wt%, the nanofibers tended to bundle and 6.79% decrement of air permeability was observed. Specifically, the softness of the MSLB was improved by 88.55%. Moreover, the thermal stability and the tear strength were also obviously enhanced. Consequently, this research provided a feasible and promising way to prepare a high-performance MSLB using TPU/SPSf nanofibers.

Nowadays the waterborne polyurethane (WPU) is a newly developed polymer foam material as a replacement for conventional organic solvent‐based polyurethane (PU). Nevertheless, the WPU foams exhibit some drawbacks such as inferior mechanical strength, low thermal and dimensional stability, which inhibits its large‐scale application at present. So a series of novel WPU/silver nanocomposite foams was successfully prepared by mechanical foaming method. The effect of silver nanoparticles (nano Ag) content on the morphology, thermal behavior, air permeability, water vapor transmission rate (WVT), mechanical, and antibacterial properties of WPU/Ag nanocomposite foams were systematically investigated. The results revealed that the nano Ag were uniformly dispersed in WPU matrix and facilitated cell growth, leading to enhanced mean pore size, thermal stability, air permeability, and WVT value of nanocomposite foams. About 122% improvement in the air permeability and 28% improvement in the WVT value were obtained when the nano Ag content extended from 0 to 4 wt%. It was found that the nano Ag content had great influence on tensile strength and elongation at break. When nano Ag content was 2 wt%, the nanocomposite foam exhibited the maximum tensile strength value of 1.26 MPa. Moreover, because of the addition of nano Ag, the nanocomposite foam showed bacteriostatic rate of 98.23% and 97.38% against Escherichia coli and Staphylococcus aureus, respectively. POLYM. COMPOS., 40:1492–1498, 2019. © 2018 Society of Plastics Engineers

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The microfiber synthetic leather base (MSLB) was prepared by mixing hollow segmented pie microfibers and polyacrylonitrile electrospun nanofibers. Micro/nano hybrid leather base was prepared to simulate the three-dimensional (3D) structure of natural leather. The diameter of the polyacrylonitrile nanofibers was 950 nm, 450 nm and 200 nm, respectively. The effects of nanofibers of different diameters on the performances of MSLB were investigated. The results indicated that polyacrylonitrile nanofibers were randomly dispersed in MSLB. Differential scanning calorimetry further demonstrated the presence of polyacrylonitrile nanofibers in MSLB, and thermogravimetric analysis showed that the addition of polyacrylonitrile nanofibers had a little influence on the thermal stability of MSLB. There was no significant change in the water contact angle of the MSLB surface before and after the addition of nanofibers. As the diameter of the nanofibers decreased from 950 nm to 200 nm, the static water vapor transmission rate was increased by 28.2%, the softness was increased by 39.74%, and air permeability was decreased by 17.16%. When the nanofiber diameter is 950 nm, the moisture absorption performance of MSLB was better, which was 768.99%. Moreover, the tear strength was also significantly enhanced by 105.76%.

A split microfiber synthetic leather using split microfiber nonwoven as the base and waterborne polyurethane(WPU)coating as the polymer coating was prepared by a dry transfer-coating method. First, the nylon/polyester (N/P) split microfiber nonwoven was manufactured, and the structure and properties were investigated. FESEM analysis indicated fiber diameter size was between 2.2~5.5 μm, and performance attaributes met the demands of textiles-nonwovens for synthetic leather. Then the effect of coating-forming temperature, foaming agent concentration and foaming ratio on the structure and performance of WPU coatings were systematically studied. Finally, the structure and properties of the split microfiber synthetic leather were analyzed. The results showed that the split microfiber synthetic leather arranged in a three-layer configuration, and its air permeability, tensile strength, elongation at break, tear strength, peeling strength and creasy recovery angle were better than knitted synthetic leather and real leather.