Improvement of wood properties by impregnation with macromonomeric initiators (macroinimers)

Scotch pine, eastern spruce, and eastern beech samples sawed longitudinally were impregnated with a new type of polymerization mixture (macroinimer and styrene), leading to crosslinked block copolymers of styrene and poly(ethylene glycol). Weight gains of 36.37–91.13% were obtained after polymerization for 2 h. Water uptake of the polymerized wood was found to be 35.13–72.07% after a water soak test of 144 h. While spruce gave the highest uptake (72.07%), beech showed the lowest value (35.13%). The specimens impregnated with the mixture of macroinimer and styrene showed a water-repellent effectiveness of 35.14–58.15% after a water soaking test of 144 h. The highest values of water-repellent effectiveness were found for spruce, while the lowest values were obtained for pine. A maximum antiswell efficiency (ASE) of 42.43% was obtained for spruce, followed in order by beech and pine, respectively. The ASE value increases with an increase in wt % gain. Improvements of 19.12% in longitudinal compression and 25% in bending strength were also achieved for spruce samples with low weight percent gain. IR spectroscopy was used for chemical characterization of the wood–polymer composite. © 1993 John Wiley & Sons, Inc.