Preparation and characterization of modified castor oil via photo‐click chemistry forUV‐curable waterborne polyurethane with enhanced water resistance and low conductive percolation threshold

Abstract

A castor oil (CO) was modified via thiol-ene click chemistry reaction between CO and 3-mercaptopropyl trimethoxysilane, with the conversion of C C bonds of CO over 99% based on 1 HNMR spectra. The obtained modified castor oil (MCO) was used as a biobased polyol to prepare waterborne polyurethane (WPU) dispersions. The modification of CO exhibited a great effect on the properties of WPU dispersions and coatings, and an obvious change is the improvement of the water resistance of WPU coatings. WPU dispersions with MCO had good storage stability. A WPU coating with 7% MCO had high surface hydrophobicity, and its water absorption was as low as 3.2%. Conductive carbon black filled WPU coatings with MCO were cured by efficient UV radiation, and their conductive percolation threshold could decrease to 0.76%, which could be attributed to the well filler dispersion and strong filler-polymer interaction. The WPU dispersions are ecofriendly, and can be used to produce biobased WPU coatings with a great application potential in antistatic coating fields.

Biobased Castor Oil-Based Polyurethane Foams Grafted with Octadecylsilane-Modified Diatomite for Use as Eco-Friendly and Low-Cost Sorbents for Crude Oil Clean-Up Applications

“…This contact angle increment was due to the low surface tension of silane coupling agents, which formed a cross-linked Si−O−Si network. This resists the water molecules entrapped into the PU skeleton [ 66 ], which was in good agreement with SEM images of the modified PU sample ( Figure 2 c1–c4). The results also show consistency with our previous latest work, which represents the physical entrapment of C18-DE on commercial PU sponges [ 57 ].…”

Synthesis and Characterization of Crosslinked Castor Oil-Based Polyurethane Nanocomposites Based on Novel Silane-Modified Isocyanate and Their Potential Application in Heat Insulating Coating

“…Obviously, the water contact angle was increased due to the addition of MPTMS. It has been reported that the crosslinking structure and low surface tension could increase hydrophobic properties [43]. Hence, due to low surface tension and a high degree of crosslinking of the Si-O-Si network structure, which is formed by introducing MPTMS, the contact angles of the CPUSi coating are enlarged, and water molecules are harder to moisten on the surface of the layer.…”

Incorporation ofCO2‐polyols into ester‐based waterborne polyurethane: An effective strategy to improve overall performance

“…[1][2][3] Water-borne polyurethanes (WPUs) with negligible VOCs were the promising alternatives, whose core technology involves the introduction of hydrophilic groups (i.e., carboxylate, sulfonate, and quaternary ammonium salt) into a hydrophobic polyurethane chain, affording excellent dispersibility in water through internal emulsification. 4,5 Owing to the advantages of environmental friendliness, economic efficiency safe and reliable, excellent compatibility, and modifiability, WPUs have been widely used in coatings, 6,7 adhesives, 8 printing inks, 9 textile composites 10 and biomaterials and so forth. 11 As an important kind of WPU, ester-based WPUs exhibit excellent hydrothermal stability, oil resistance and high strength thanks to high cohesive energy density of oligoesterol from soft segment, which has been widely applied on the adhesives and fabric after-finishing treatment and so forth.…”