Novel waterborne polyurethanes extended by glycerol monostearate: their synthesis and application to water repellency

In this paper, a string of waterborne polyurethane (WPU) emulsions synergistically modified with PDMS and GMS were successfully prepared by incorporating Polydimethylsiloxane (PDMS) into the soft segments of waterborne polyurethanes, and using glycerol monostearate (GMS) as a chain extender. FTIR, TGA, SEM, particle size test, water contact angle and other tests were used to characterize the effects of variable GMS contents on the structure and function of WPUs. The experimental tests showed that the WPUs synthesised with 30% PDMS-8% GMS synergism had better overall performance. The water contact angle could reach 115.4°, and the water absorption was reduced to 10.52% at 72 h. Furthermore, this innovative WPU film had excellent thermal stabilization, and this study provided a new approach to improve waterproofing performance, hydrophobicity and thermal stability of waterborne polyurethanes, which is expected to be applied in coatings, adhesives and water-resistant agents.