Effects of post-treatment with alkaline copper quat and copper azole on the mechanical properties of wood-based composites

Abstract

Two new triterpene glycosides, 3-ter (gazipashoside B, 2), were isolated together with 11 known compounds including 7 triterpene, 1 flavonoid, and 3 iridoidal metabolites from the aerial parts of Cephalaria gazipashensis (Dipsacaceae) . The structures of all compounds were elucidated by extensive evaluation of the spectroscopic data (1D-and 2D-NMR, HRESI-MS), as well as chemical examinations. The antimicrobial effects of all pure compounds were tested against gram-positive and gram-negative bacteria. The results indicated that the 2 new triterpene glycosides might be acceptable as antimicrobial active agents.

Previous Preservation of Veneers Promotes Higher Preservative Retention and More Effective Protection in CCA-Preserved Plywood

“…This association of occurrences suggests a probable harmful action of the active ingredients of the preservative product CCA-C on the mechanical performance of the plywood panel, as attributed by the Wood Handbook (IBACH, 2010) and by Acker and Stevens (1993), Vick and Kuster (1992) and Pinheiro (2001). This finding is contrary to that reported in the literature by Taşçioğlu et al (2014) and by Mendes et al (2013) who attributed the drop in properties to pressure treatment.…”

“…Despite the benefits of preservative treatment of wood and its by-products, the active ingredients of preservative products, such as chromium, copper and arsenic, react with wood during fixation, causing significant reductions in mechanical properties, especially if the drying processes are not controlled (TSOUMIS, 1991;VICK;KUSTER, 1992;ACKER;STEVENS, 1993, BARNES et al, 1996PINHEIRO, 2001;IBACH, 2010;MENDES et al, 2013;SEGUNDINHO et al, 2017). Other research suggests that the vacuum-pressure system and not the preservative itself would be the cause of the drop in physical-mechanical properties (TAŞÇIOĞLU; TSUNODA, 2010;MENDES et al, 2013;TAŞÇIOĞLU et al, 2014). The treatment of wooden panels would cause excessive swelling, in some cases irreversible, damaging the other properties.…”

Decay Resistance of Bamboo Oriented Strand Board Pretreated with Copper-based Preservatives

“…It may be concluded that pretreatment with ACQ and CA within the investigated loading levels may not have detrimental effects on the physical and mechanical properties of bamboo OSB. In contrast, the post-treatment of vacuum-impregnation with ACQ (retentions: 0.65, 1.30, and 2.60 kg/m 3 ) and CA (0.25, 0.50, and 1.0 kg/m 3 ) was found to have negative effects on the MOE and MOR of OSB (Taşçioğlu 2013). Tascioglu and Tsunoda (2010a,b) also concluded that post-treatment with CA and ACQ was impractical for OSB because of the resulting high thickness swelling.…”

“…Because the solutions of waterborne ACQ and CA preservatives are normally low in concentration, an in-process treatment, which generally incorporates preservatives with dry wood elements before mat forming and hot-pressing, may result in very high mat moisture content, which in turn brings up challenges and difficulties for hot-pressing. Post-treatment with these preservatives often involves pressure impregnation and a subsequent drying process that causes excessive thickness swelling and thus has possible detrimental effects on both the structure and properties of OSB and other non-veneer wood composites (Tascioglu and Tsunoda 2010a, b;Taşçioğlu 2013). In contrast, with pretreatment, i.e., dipping or impregnating strands in dilute preservative solution, the treated strands can then be dried and used subsequently for OSB manufacturing.…”

Water absorption, thickness swelling and mechanical properties of cement bonded wood composite treated with water repellent

“…Wood-based composites can be protected by various methods including pre-treatment of particles, in-process treatment during manufacturing process, post-treatment after manufacturing of composites (Kirkpatrick andBarnes 2006, Taşçıoğlu 2013). The most practical way to protect composites could be post-treatment after manufacturing the composites by dipping, spraying, brushing or vacuum-pressure treatment (Taşçıoğlu 2013). Depending on the desired properties of cement-bonded wood composites, physical and mechanical properties can be improved with several factors such as cement-wood ratio, particle size and geometry, orientation of particles, treatment of particles or treatment composites with water repellent among other.…”