Effect of densification of heat - treated brutian pine (Pinus brutia Ten.) and black poplar (Populus nigra L.) wood on some physical, menhanical and chemical properties

In this study, heat-treatment was applied to brutian pine (Pinus brutia Ten.) and black poplar (Populus nigra L.) wood samples at 120, 160 and 200oC, and then the samples were pressed in the ratio of 25% and 50% for densification. FTIR spectroscopic and thermal properties of heat-treated samples were investigated. The physical and mechanical properties of the heat-treated and densified samples were evaluated. FTIR findings showed that there was no remarkable change in the crystallinity index of the samples due to heat-treatment. It was observed that the heat-treated samples had lower material loss than the control samples at the main decomposition phase in the TGA and DTG curves. However, according to the TGA and DTG findings, it was determined that a significant level of holocellulose loss occurred in the samples with the increase of the temperature applied in the heat-treatment. In the results obtained, it has been seen that it can be recommended to apply heat treatment before densification, if the thermo-mechanically densified brutian pine and black poplar samples are considered to be used in environments where they can come into contact with water. In addition, heat-treatment and densification methods can be recommended to be used together for increase the usability of working types in load-bearing applications and outdoor (siding, park and garden furniture, etc.) or indoor (paneling, parquet, sauna, furniture elements, etc.) applications, as well as partially fire-resistant structures.