Chemical modification of spruce wood with combination of mesyl chloride and poly(ε-caprolactone) for improvement of dimensional stability and water absorption properties

Sustainability is an important issue for materials production which can be provided by using renewable resources such as wood. Wood is a natural material with excellent mechanical properties. However, humidity changes negatively affect wood’s dimensional stability. Water repellence and dimensional stability can be both improved by inserting hydrophobic molecules inside wood cell walls. In this study, a two-step modification were carried out by grafting a biodegradable polymer poly(e-caprolactone) (PCL) onto the pre-treated wood cell walls by mesyl chloride. Confocal Raman imaging and spectroscopy were used to show the distribution of mesyl groups and poly(e-caprolactone) within cell walls. The morphology of modified wood cell walls was monitored by scanning electron microscopy. Physical tests showed that the poly(e-caprolactone) grafted wood has significantly better dimensional stability and water repellence compared to references.