In Situ Construction of Multifunctional Organosilicon/Organic Hybrid Resin Coatings on Wood Surfaces Based on the PMHS Si-H Click Reaction.

The abundant hydrophilic hydroxyl groups and porous structure make wood highly susceptible to moisture absorption from the environment, leading to issues such as deformation and decay. This work aims to in situ construct a multifunctional organosilicon/organic hybrid resin coating on the wood surface derived from the click reaction of polymethylhydrosiloxane (PMHS), using PMHS, divinylbenzene (DVB), and the Karstedt catalyst. At room temperature, through the Si-H addition click reaction between PMHS and DVB, a cross-linked and rigid hybrid resin coating with a hardness of 94.00 HA is fabricated on the wood surface. Simultaneously, a dehydrogenation click reaction takes place between the Si-H groups of PMHS and the -OH groups on the wood surface, anchoring the hybrid resin coating to the wood via covalent bonds. These endow the hybrid resin coating with excellent mechanical stability. The low surface energy of organosilicon resin in the hybrid coating affords the modified wood with good waterproofness by decreasing the 24 h water absorption rate from 78.6% to 13.9%. Most importantly, the coating remains hydrophobic even after being immersed in an alkaline solution (pH = 13) for 24 h. SEM images of the coating after alkaline corrosion indicate that while the Si-O-Si skeleton of the organosilicon component is partially dissolved due to its susceptibility to alkali, the hydrophobic organic resin skeleton remains intact, imparting good alkali resistance to the hybrid resin coating. In summary, the organosilicon/organic hybrid coating constructed via the click reaction of PMHS on the wood surface effectively addresses the issue of poor alkali resistance commonly associated with traditional organosilicon coatings.