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Kraft cooking of juniper wood with NaOH/Na2S aqueous solution has been used in the study for partial delignification at the temperature of 165°C for different residence time (0-40 min) following by thermal compression for densification under a pressure of 5 MPa at 100°C for 24 hours. The densified and natural juniper wood samples were characterized...
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Context 1
... thickness of control samples, which were dry-and wet-densified, decreased by 12% and 47%, while for chemically pretreated and densified samples -in range of 62-73%. The impact of Kraft cooking on juniper wood's mass loss and contents of lignin and extractives is shown in Table 1. Partial degradation and thermal modification of lignin was performed during Kraft cooking pretreatment and relative content of lignin decreased by 16-23%. ...Context 2
... content (34%) in the juniper wood is higher than in other popular softwood [15][16], as example in pine 24-29% [13] and spruce 26-28% [17]. Table 1 shows that the detected lignin content of chemically pretreated juniper ...Citations
... A compressed wood density of 1170 kg/m 3 was achieved (100% increase compared to natural juniper wood). The modulus of rupture was increased by 85%, reaching 174 MPa, and the modulus of elasticity by 620%, reaching 12,500 MPa [69]. ...
... Chemical pretreatment makes it possible to reduce the variability of the chemical composition. Chemical pretreatment of wood and subsequent densification is a promising method for wood processing to obtain implants with density and mechanical strength suitable for osteosynthesis biomaterials [69]. ...
... Authors Andze L. et al., in a mechanical study, increased juniper's density by 100%, reaching almost 1200 kg/m 3 . The MOR and MOE were increased by 85% and 620%, accordingly [69]. Studies of wood's mechanical properties show that natural wood is not strong enough to produce durable orthopedic implants for bone fracture fixation. ...
Bone fractures and bone defects affect millions of people every year. Metal implants for bone fracture fixation and autologous bone for defect reconstruction are used extensively in treatment of these pathologies. Simultaneously, alternative, sustainable, and biocompatible materials are being researched to improve existing practice. Wood as a biomaterial for bone repair has not been considered until the last 50 years. Even nowadays there is not much research on solid wood as a biomaterial in bone implants. A few species of wood have been investigated. Different techniques of wood preparation have been proposed. Simple pre-treatments such as boiling in water or preheating of ash, birch and juniper woods have been used initially. Later researchers have tried using carbonized wood and wood derived cellulose scaffold. Manufacturing implants from carbonized wood and cellulose requires more extensive wood processing—heat above 800 °C and chemicals to extract cellulose. Carbonized wood and cellulose scaffolds can be combined with other materials, such as silicon carbide, hydroxyapatite, and bioactive glass to improve biocompatibility and mechanical durability. Throughout the publications wood implants have provided good biocompatibility and osteoconductivity thanks to wood’s porous structure.
