Preparation and properties study of waterborne polyurethane synthesized by mixing polyester diols and isocyanates

Abstract

In view of environmental protection requirements, it is an inevitable trend for waterborne coatings to replace traditional coatings. Waterborne polyurethane (WPU), a kind of typical resin used in coatings, has become a research hot topic of waterborne coatings because of its advantages, such as non‐polluting, safe and reliable, excellent properties, good compatibility, and easy modification. In this article, solvent‐free WPU is prepared by mixing 4,4′‐dicyclohexylmethane diisocyanate/ isophorone diisocyanate (HMDI/IPDI) and polycarbonate diol/ Polycaprolactone diol (PCDL/PCL). Through the comparison of the properties of the polymer, the best amount of raw materials was determined. Specifically, R = 1.35 (R is NCO/OH ratio), the content of dimethylolpropionic acid (DMPA) is 5.5%, the content of trimethylol propane (TMP) is 2.5%, the mole ratio of HMDI/IPDI is 2:1, the mole ratio of PCDL/PCL is 2:1, and the preeminent WPU shows the excellent thermal stability, the contact angle of 118.04°, the hardness is H. The chemical structures and rough surface morphologies of the WPU films were characterized by FT‐IR, TG, AFM, and SEM, respectively. Therefore, considering the film properties, and the low cost, simple, and green process, this research will offer the possibility of application of this free‐solvent WPU in industrial production and large‐scale application.

Antibacterial and Alkali-responsive Cationic Waterborne Polyurethane Based on Modification of Aloe Emodin

“…Based on CWPU, the antibacterial effect of its quaternary ammonium salt, combined with the antibacterial properties of AE, is used to achieve synergistic antibacterial effect. The addition of AE to CWPU improved the thermodynamic properties and maintained the pH response properties [31] .…”

Triethoxysilane End-Functional Branched Waterborne Polyurethane Adhesives for Leather Substrates

“…9−11 However, the introduction of hydrophilic groups leads to the deterioration of water resistance, mechanical properties, and thermal stability of the WPU film; as a result, its application in some fields is limited. 12,13 In order to solve the above problems, graphene oxide, 14 phosphate ester, 15 acrylic ester, 16 organofluorine, and organosilicone 17 have been used in the modification of WPU. Among them, because the organosilicone is characterized by good thermal stability, weather resistance, and excellent hydrophobicity, many researchers introduced the linear organosilicone molecules into the WPU structure via physical blending, 18 copolymerization modification, 19 interpenetrating network (IPN) polymerization, 20 and emulsification to improve the water resistance of the WPU film.…”

A Study on the Dye Fixation Mechanism of Waterborne Polyurethane

“…Because of its high tensile strength, [1] high wear resistance, [2] high flexibility, [3] good adhesion performance [4] and low temperature resistance, [5] etc., waterborne polyurethane (WPU) [6][7][8][9] has been widely used in many fields including dye fixation. [10,11] WPU dye fixing agents are mostly cationic quaternary ammonium salts, [11,12] and non-ionic WPU dye fixing agents are rarely seen in the market.…”