In-Situ Synthesis of Hydrophobic Polyurethane Ternary Composite Induced by Hydroxyethyl Cellulose through a Green Method for Efficient Oil Removal

Abstract

Hydroxyethyl cellulose (HEC) was introduced to activate the surface of polyurethane (PU) sponge to successfully prepare a hydrophobic ternary composite PU/HEC/SiO2. The hydrophobic layer of the composite was realized by in-situ polymerization of methyltriethoxysilane (MTES) onto the surface of PU sponge. The formation of a stable hydrophobic SiO2 layer solved successfully the problem of ease of SiO2 particles shedding from the composite. Moreover, the amphiphilic molecules produced by the hydrolysis of MTES monomers facilitated the preparation of hydrophobic materials by aqueous dispersion polymerization. Aqueous synthesis made the reaction process environmentally-friendly and pollution-free. The as-prepared composite PU/HEC/SiO2 not only retains high porosity and low density of the PU sponge, but also considerably reduced the surface free energy and increased the surface roughness of the PU sponge. Therefore, outstanding hydrophobicity and high porosity endow the composite with excellent oil removal capability as a high-efficiency absorbent. Moreover, the hydrophobic composite that had absorbed oil could be regenerated easily by squeezing and recycling.

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

“…The lightweight and open-cell PU foam gained popularity among other polymeric adsorbents due to high porosity, good elasticity, easy industrial production and high oil sorption at low and high viscosity of oils and derivatives [ 21 , 22 , 23 ]. However, the presence of PU moieties in the network reduces hydrophobicity, which can be improved by various techniques such as chemical vapor deposition [ 24 ], dip coating [ 25 ], in situ chemical reaction [ 26 ] and introduction of micro-nano particles [ 27 ]. In recent work, a one-step ultrasonic dip-coating process [ 28 ] was used to prepare a superhydrophobic sepiolite (SEP)-coated PU sponge for oil spill clean-up from the water’s surface.…”

“…The PU industries primarily depend on depleting petroleum-based resources for synthesizing primary raw materials, such as polyols and isocyanates. To overcome this limitation, current researchers have focused on using sustainable resources from plant oils [ 26 ], starch [ 41 ], chitosan [ 42 ] and cellulose [ 43 ], intending to replace petroleum products. These substituent natural resources have innumerable advantages, such as being inexpensive, readily available and eco-friendly for synthesizing biodegradable PU foams to avoid pollution and waste disposal.…”