Organosilicon compound reactivity with biologically and chemically degraded Scots pine as determined by 1H–13C HSQC NMR

Abstract

Ancient archeological wooden artifacts hold important stories from our history that can only be retold through wood conservation. Understanding the detailed mechanisms of how to stabilize these fragile artifacts dimensionally is necessary to effectively preserve them for the next generations. In this study, highly effective organosilicons are used to treat and infiltrate model degraded wood. We used wood dissolution techniques, in conjunction with two-dimensional nuclear magnetic resonance spectroscopy, to characterize the changes occurring to native wood cell wall polymers before and after organosilicon treatments. Methyltrimethoxysilane was shown to be the mildest organosilicon towards wood polymer depolymerization in the model woods, while the alkoxysilane with a mercaptopropyl group resulted in more dramatic cell wall depolymerization, removing lignin linkages and polysaccharides. The siloxane treatment did depolymerize the model woods as well, giving more intermediate cell wall depolymerization and leading to reduction of the α-carbonyl in G-2ʹ guaiacyl units in lignin. We hypothesize that the organosilicon treatments can effectively infiltrate cell wall matrices, partially depolymerize wood cell wall polymers, and meld the truncated wood polymers together to stabilize cell wall dimensions.