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

Abstract

Waterproof-breathable (WB) materials with outstanding waterproofness, breathability, and mechanical performance are critical in diverse consumer applications. Electrospun nanofibrous membranes with thin fiber diameters, small pore sizes, and high porosity have attracted significant attention in the WB fabric field. Hot-press treatment technology can induce the formation of inter-fiber fusion structures and hence improve the waterproofness and mechanical performance. By combining electrospinning and hot-press treatment technology, polyurethane/fluorinated polyurethane/thermoplastic polyurethane/alkylsilane-functionalized graphene (PU/FPU/TPU/FG) nanofiber WB fabric was fabricated. Subsequently, the morphologies, porous structure, hydrostatic pressure, water vapor transmission rate (WVTR), and stress–strain behavior of the nanofiber WB fabric were systematically investigated. The introduction of the hydrophobic FG sheet structure and the formation of the inter-fiber fusion structure greatly improved not only the waterproofness but also the mechanical performance of the nanofiber WB fabric. The optimized PU/FPU/TPU-50/FG-1.5 WB fabric exhibited an excellent comprehensive performance: a high hydrostatic pressure of 80.4 kPa, a modest WVTR of 7.6 kg m−2 d−1, and a robust tensile stress of 127.59 MPa, which could be used to achieve various applications. This work not only highlights the preparation of materials, but also provides a high-performance nanofiber WB fabric with huge potential application prospects in various fields.

Preparation of Fluorine‐Free Waterproof and Breathable Electrospun Nanofibrous Membranes via Thiol‐ene Click Reaction

“…Proper cross‐linking between the nanofibrous membranes can give them better waterproofness. [ 21,35 ] The thiol content in the nanofibrous membranes is an important factor affecting their chemical cross‐linking. Si‐PU/PMMA/TMTVSi/thiol nanofibrous membranes were obtained by fixing the TMTVSi content at 20 wt% and varying the thiol content (0, 15, 30, and 45 wt%); the corresponding SEM images are shown in Figure a–d.…”

“…Poor adhesion between the substrate (membrane) and the coating agent restrained the application of the coating method. The heating method involved the formation of physical fusion [ 21 ] or chemical cross‐linking [ 22 ] between the nanofibrous membranes, which could change their pore structure. Sheng et al.…”

“…Poor adhesion between the substrate (membrane) and the coating agent restrained the application of the coating method. The heating method involved the formation of physical fusion [21] or chemical cross-linking [22] between the nanofibrous membranes, which could change their pore structure. Sheng et al [22] achieved physical fusion (polyvinyl butyral (PVB) was heated to melt) and chemical cross-linking (blocked isocyanate prepolyme was heated to unseal and crosslink with PVB) between the fluorinated polyurethane /polyacrylonitrile /PVB electrospun nanofibrous membranes by heating.…”

A review on emerging developments in thermal and moisture management by membrane‐based clothing systems towards personal comfort

“…Using an electrospun PVDF layer hybridized with a hydrogel layer, a WBM was produced by Amini et al 138 They stated that molecular diffusion and Knudsen molecular diffusion on the surface are the main mechanisms of moisture transfer in the PVDF layers and hydrogel & hybrid layers, respectively. Fabrication of a hybrid WBM composed of PU/FPU/TPU/alkylsilane‐functionalized graphene (FG) via electrospinning and hot‐press treatment was regarded by Liu et al 139 They observed that hydrophobic FG sheet structure and the inter‐fiber fusion structure created after hot‐press treatment significantly improved the waterproofness of the hybrid WBM. It has been reported that electrospun membranes composed of PVDF and polyvinyl butyral (PVB) along with blocked isocyanate prepolymer (BIP) as the chemical cross‐linker, provides a WBM with good mechanical strength 140 .…”

Wearable Textile UHF-RFID Sensors: A Systematic Review

“…In addition, reliability is an unavoidable but crucial research direction especially for this kind of flexible and washing-needed component [85]. For example, after fabricating the designs on textile substrates, the performance of UHF-RFID antenna and sensors may decrease such as the resonant frequency shift and gain penalty due to conformal bending or on-body touching.…”