Effect of poplar wood impregnation with epoxidized soybean oil on the set recovery

Regarding the shortage of the wood resources in the country and the increasing trend for using them as constructional materials, densification of planted fast growing species in order to improve the physical and mechanical properties is inevitable. In the present study, poplar wood samples were impregnated with raw and epoxidized soybean oil and densified to the compression ratio of 30%. Heat treatment was used to overcome the set recovery problem. Results of the set recovery test showed that the set recovery values for samples impregnated with epoxidized oil were lower than the ones impregnated with raw oil. Heat treatment decreased the set recovery values to 46 and 63% for raw oil and epoxidized oil impregnated samples respectively. Results of water absorption tests showed that for non-densified samples, impregnation with oil led to lower water absorption which was more pronounced for the epoxidized oil impregnated samples. Generally, water absorption of densified wood was higher than the non-densified ones and heat treatment lowered that. Scanning electron microscopy images and Fourier Transform Infrared Spectroscopy was used for interpretation of the set recovery test results.