Polydimethylsiloxane‐modified polyurethane–poly(ɛ‐caprolactone) nanofibrous membranes for waterproof, breathable applications

Abstract

In this study, we prepared polydimethylsiloxane (PDMS)-modified polyurethane-poly(E-caprolactone) nanofibrous membranes with excellent waterproof, breathable performances via an electrospinning technique. Field emission scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, and mechanical testing were used to characterize the morphologies and properties of the composite nanofibers. The fiber diameter and porous structure of the membranes were regulated by the adjustment of the temperatures of thermal treatment and the PDMS concentrations. The fibrous membranes obtained at a typical temperature of 70 8C possessed an optimized fibrous structure with a diameter of 514 6 2 nm, a pore size of 0.55-0.65 mm, and a porosity of 77.7%. The resulting nanofibrous membranes modified with 5 wt % PDMS were endowed with good waterproof properties (water contact angle 5 141 6 18, hydrostatic pressure 5 73.6 kPa) and a high breathability (air permeability rate 5 6.57 L m 22 s 21 , water vapor transmission rate 5 9.03 kg m 22 day 21 ). Meanwhile, the membranes exhibited robust mechanical properties with a high strength (breakage stress 5 11.7 MPa) and excellent thermal stability. This suggests that they would be promising candidates for waterproof, breathable applications.

Fluorine-Free Waterborne Coating for Environmentally Friendly, Robustly Water-Resistant, and Highly Breathable Fibrous Textiles

“…To conclude, a comparison of waterproof breathable properties among our prepared fibrous membranes and other reported records is illustrated in Figure f. PU coatings possessed medium hydrostatic pressure (60–90 kPa) but with a quite low WVT rate (<4.5 kg m –2 d –1 ). , For pristine PU fibrous membranes, they usually displayed good moisture permeability because of the interconnected pores but with low waterproof property (∼5 kPa) due to the poor hydrophobicity. − Benefiting from the intrinsic water-resistant capability, electrospun PVDF membranes exhibited increased waterproofness (∼60 kPa). − Unsurprisingly, PU membranes modified with fluorinated segments showed better waterproof breathable properties. , In terms of fluorine-free membranes, solvent-based organosilicone-modified fibrous membranes demonstrated modest waterproofness of 70–80 kPa and medium moisture permeability of 9–12 kg m –2 d –1 . , In dramatic contrast, our environmentally friendly TCA, TPA-6, and TPAN fibrous membranes, which were fabricated from fluorine-free, waterborne hydrophobic agents, displayed superior water-resistant property and water vapor transmitting ability by virtue of the robust hydrophobicity and small apertures.…”

“…Hence, designing environmentally friendly WBMs with short fluorinated or even fluorine-free components has become an irresistible trend. − More recently, nonfluorinated silicone-containing chemicals have been explored to develop WBMs. For example, Gu et al impregnated polyurethane–poly­(ε-caprolactone) fibers into polydimethylsiloxane solutions, and the obtained membranes possessed a medium waterproof breathable performance (73.6 kPa, 9.03 kg m –2 d –1 ) . Sheng et al adopted amino–silicone oil and SiO 2 nanoparticles to modify PAN fibrous membranes to prepare WBMs, and the resulting fibrous membrane exhibited similar waterproofness (74.3 kPa) and good breathability (11.4 kg m –2 d –1 ) .…”

“…For example, Gu et al impregnated polyurethane− poly(ε-caprolactone) fibers into polydimethylsiloxane solutions, and the obtained membranes possessed a medium waterproof breathable performance (73.6 kPa, 9.03 kg m −2 d −1 ). 33 Sheng et al adopted amino−silicone oil and SiO 2 nanoparticles to modify PAN fibrous membranes to prepare WBMs, and the resulting fibrous membrane exhibited similar waterproofness (74.3 kPa) and good breathability (11.4 kg m −2 d −1 ). 34 Although these studies obtained fluorine-free fibrous membranes with good properties, the heavy use of organic solvent (n-hexane) and the weak binding force between coating materials and substrates greatly limited their large-scale applications.…”

Polylactic acid based Janus membranes with asymmetric wettability for directional moisture transport with enhanced UV protective capabilities

“…In light of practical applications, not only is excellent UV protection performance important, but good moisture and air permeability, ensuring comfort, play important roles in the development of a wearable fabric. 46 Fig. 5(c) shows the air permeability of the Janus membrane as a function of the electrospinning time.…”

Hot-melt Adhesive Bonding of Polyurethane/Fluorinated Polyurethane/Alkylsilane-Functionalized Graphene Nanofibrous Fabrics with Enhanced Waterproofness, Breathability, and Mechanical Properties

“…Based on these characteristics, electrospinning technology is widely employed to prepare nanofiber WB membranes. A variety of polymers, such as polyurethane (PU) [15], nylon [16], polyacrylonitrile (PAN) [17], polyvinylidene fluoride (PVDF) [18], and polytetrafluoroethylene (PTFE) [19], have been utilized in the preparation of nanofiber WB membranes. Among these nanofibers, PU nanofibers are the most widely used due to their attractive characteristics, such as good elasticity, high durability, easy-care, and good comfort properties.…”