Effect of process variations of polycaprolactone modification on wood durability, dimensional stability and boron leaching

In this study, in situ graft polymerization of epsilon-caprolactone (CL) was studied for its potential to limit boric acid (BA) leaching from wood, and to increase the dimensional stability and biological durability of wood against Coniophora puteana and Trametes versicolor fungi. For this purpose, CL monomer with/without BA was impregnated into wood, and the monomer was polymerized in wood cell walls using various methods and combinations of reactants. It was found that biodegradable polycaprolactone (PCL) grafting at high monomer concentrations could inhibit fungal degradation of wood cell walls, as well as improve the dimensional stability of wood up to 55% and reduce water uptake (WU) by about 50%. However, inductively coupled plasma-optical emission spectrometry (ICP-OES) analysis revealed that in situ graft polymerization of CL is not an effective method to prevent BA leaching from wood.