Bio-Based Waterborne PU for Durable Textile Coatings

Synthesis and Properties of Cationic Core-Shell Fluorinated Polyurethane Acrylate

Vinyl-capped cationic waterborne polyurethane (CWPU) was prepared using isophorone diisocyanate (IPDI), polycarbonate diol (PCDL), N-methyldiethanolamine (MDEA), and trimethylolpropane (TMP) as raw materials and hydroxyethyl methacrylate (HEMA) as a capping agent. Then, a crosslinked FPUA composite emulsion with polyurethane (PU) as the shell and fluorinated acrylate (PA) as the core was prepared by core-shell emulsion polymerization with CWPU as the seed emulsion, together with dodecafluoroheptyl methacrylate (DFMA), diacetone acrylamide (DAAM), and methyl methacrylate (MMA). The effects of the core-shell ratio of PA/PU on the surface properties, mechanical properties, and heat resistance of FPUA emulsions and films were investigated. The results showed that when w(PA) = 30~50%, the stability of FPUA emulsion was the highest, and the particles showed a core-shell structure with bright and dark intersections under TEM. When w(PA) = 30%, the tensile strength reached 23.35 ± 0.08 MPa. When w(PA) = 50%, the fluorine content on the surface of the coating film was 14.75% and the contact angle was as high as 98.5°, which showed good hydrophobicity; the surface flatness of the film was observed under AFM. It is found that the tensile strength of the film increases and then decreases with the increase in the core-shell ratio and the heat resistance of the FPUA film is gradually increased. The FPUA film has excellent properties such as good impact resistance, high flexibility, high adhesion, and corrosion resistance.

Review of Waterproof Breathable Membranes: Preparation, Performance and Applications in the Textile Field

Waterproof breathable membranes (WBMs) characterized by a specific internal structure, allowing air and water vapor to be transferred from one side to the other while preventing liquid water penetration, have attracted much attention from researchers. WBMs combine lamination and other technologies with textile materials to form waterproof breathable fabrics, which play a key role in outdoor sports clothing, medical clothing, military clothing, etc. Herein, a systematic overview of the recent progress of WBMs is provided, including the principles of waterproofness and breathability, common preparation methods and the applications of WBMs. Discussion starts with the waterproof and breathable mechanisms of two different membranes: hydrophilic non-porous membranes and hydrophobic microporous membranes. Then evaluation criteria and common preparation methods for WBMs are presented. In addition, treatment processes that promote water vapor transmission and prominent applications in the textile field are comprehensively analyzed. Finally, the challenges and future perspectives of WBMs are also explored.

Potent environmental-friendly virucidal medical textiles against coronavirus to combat infections during the COVID-19 pandemic

The sudden outburst of Coronavirus disease 19 or COVID-19 has raised serious awareness about viral contamination on the environment, which is one of the major causes of the disease. Transmission via contaminated surfaces has been recognized as a significant route for spreading the virus. To suppress and control the spread of SARS-CoV-2, potent virucidal finishing agents for decontamination of medical textiles are urgently required. In this study, an environmental-friendly, economical, non-toxic, and practical finishing on medical textiles with potent virucidal activity was proposed with the combined concepts of a new green synthesis of TiO2@Ag core-shell nanostructures using ascorbic acid reduction and UV-curing process. In order to evaluate efficiency of virucidal activity, effects of the amount of TiO2@Ag NPs and contact time were determined against the coronavirus following ISO 18184:2019 standard. The finishing agent exhibited an excellent 99.9% virucidal efficacy. The stability of virucidal activity and mechanical properties were determined under repeated washing. The finished fabrics had the ability to retain their virucidal activity and tensile strength through 20 washes. The results suggested that the finishing agent had great potential as a potent and non-toxic virucide against the coronavirus for medical textile applications.