Mechanical properties and set recovery of compressed poplar with glycerin pretreatment
In order to improve the mechanical properties of low-density wood, the densified wood was fabricated. Northeast China fast-growing poplar was firstly immersed in 50% glycerin for 24 h, and then compressed under 150°C to attain 60% compression ratio with different thermal modification time (0.5, 1, and 2 h). The set recovery, modulus of elasticity (MOE), modulus of rupture (MOR) and hardness of compressed wood were tested to assess the influence of thermal modification time and wet/dry cycles on mechanical properties and set recovery of compressed poplar with glycerin pretreatment. It can be found that the thermal modification time of 1 h can be more appropriate, the first wet/dry cycle has a significant effect on mechanical properties and set recovery of compressed wood due to the dilution of glycerin during the soaking.