Facile fabrication of a PDMS @ stearic acid-Al(OH)3 coating on lignocellulose composite with superhydrophobicity and flame retardancy

Some disadvantages such as deformation after absorbing water and inflammability limit the large scale applications of lignocellulose composites. In this study, a facile method was provided to fabricate a superhydrophobic and flame retardant coating on lignocellulose composite by depositing polydimethylsiloxane (PDMS) and stearic acid modified nano-Al(OH)3 (STA-ATH). The obtained superhydrophobic and flame retardant lignocellulose composite had a water contact angle (WCA) of ∼156°. The as-prepared coating was capable of maintaining the superhydrophobicity after mechanical damages and different temperatures aging. Furthermore, for the superhydrophobic lignocellulose composite, an excellent flame retardancy with a limiting oxygen index value of 36.0 was obtained by inheriting the flame retardancy of ATH particles. Cone calorimetry results indicated that the ignition time of the PDMS@STA-ATH coated samples increased by 16 s compared with that of the uncoated samples. Moreover, the coating of PDMS@STA-ATH made the peak heat release rate (PHRR) and the total smoke production (TSP) of lignocellulose composite reduced by 32.7% and 14.8%, respectively. This work offers a new strategy for improving hydrophobicity, decreasing flammability and smoke release, and promoting high value-added utilization of lignocellulose composites.