Preparation and properties of fluorinated silicon two‐component polyurethane hydrophobic coatings

Abstract

A polyurethane (PU) hydrophobic coating was prepared by the two-component method, polycarbonate diol and isophorone diisocyanate becoming a two-phase composition. The PU films with hydrophobic surface were prepared by establishing a rough structure on the surface of silica (SiO 2 ) modified with silane coupling agents (γ-(2,3-epoxypropoxy)propytrimethoxysilane (KH560) and (heptadecafluoro-1,1,2,2-tetradecyl)trimethoxysilane (FAS)). First, the surface of SiO 2 was covered by a layer of hydrophobic methyl and fluorocarbon (C-F) groups. Then, the SiO 2 and modified SiO 2 were obtained by the introduction of KH560 and FAS with the silanol reaction by ultrasonic stirring. The effect of SiO 2 and modified SiO 2 on the structure and hydrophobic properties of PU was investigated by a series of test instruments. The results showed that the introduction of SiO 2 and modified SiO 2 was beneficial for increasing the roughness of the PU coating surface; the roughness of FAS/SiO 2 -PU could reach up to 14.790 nm, four times better than pure PU. A hydrophobic modified PU coating with water contact angle 123°was fabricated by using the hydrophobic C-F group FAS as a low surface energy material and establishing a micro rough structure on the surface of PU. Moreover, PU modified with KH560 and FAS can reduce the glass transition temperature (T g ) of soft segments, resulting in improvement of micro-phase separation.

Interpenetrating network structure design and corrosion resistance of high‐performance waterborne polyurethane coating modified by epoxy resin and functionalized graphene oxide

“…According to the data, the storage modulus values of all samples at −75°C are greater than 4000 MPa, indicating all the samples have the strong ability to store elastic deformation energy, that is, the strong capability to restore the original deformation after the removal of stress. This bears resemblance to such properties of rubber as high deformation storage and low internal friction, which has huge application potential in the field of low temperature elasticity 21 . As can be seen from Figure 8a, the storage modulus increases from 4022 (pure WEPU film) to 5045 MPa (the iGO‐WEPU composite film with 1.0 wt% iGO loading), and that of iGO‐WEPU composite films increases with increasing the fillers at low temperature (less than 25°C), showing high viscoelastic properties.…”

“…This bears resemblance to such properties of rubber as high deformation storage and low internal friction, which has huge application potential in the field of low temperature elasticity. 21 As can be seen from Figure 8a, the storage modulus increases from 4022 (pure WEPU film) to 5045 MPa (the iGO-WEPU composite film with 1.0 wt% iGO loading), and that of iGO-WEPU composite films increases with increasing the fillers at low temperature (less than 25 C), showing high viscoelastic properties. As the iGO loading increases, the tan δ (T g ) of iGO-WEPU composite films reveals a slight increase.…”

Transcrystalline growth of PLLA on carbon fiber grafted with nano-SiO 2 towards boosting interfacial bonding in bone scaffold

“…In the spectrum of SiO 2 , there was no peak and the curve was smooth from 2750 cm − 1 to 3000 cm − 1 . In the spectrum of SiO 2 -KH560, two absorption peaks at 2940 cm − 1 and 2873 cm − 1 attributable to the -CH 3 and -CH 2 - stretching vibration in KH560, respectively, were observed [ 33 , 34 ]. For the CF-COOH specimen, the obvious absorption peak of -OH at 3438 cm − 1 and stretch vibration peak of -C=O at 1627 cm − 1 were observed.…”

Effect of surface modification of SiO2 particles on the interfacial and mechanical properties of PBS composites

“…[ 14 ] Meanwhile, the strong and sharp peak at 1096 cm −1 and the absorption peak at 795 cm −1 , corresponding to SiOSi antisymmetric stretching vibration and the stretching vibration of the SiO. [ 15 ] However, there is an absorption peak at 3435 cm −1 of SiO 2 , which belongs to the stretching vibration of OH on the SiO 2 surface. The results show that WPU has been adsorbed on the SiO 2 surface successfully.…”