Papers by Keyword: Extractives

Abstract: The apparent shift in climate has resulted in the pursuit of environmentally friendly bio-based products to reduce the carbon footprint. In the scientific literature, there are many attempts to make phenol-formaldehyde resins (PFR) more sustainable by using bio-based phenolics in the synthesis instead of petroleum-based phenol. However, it is also important to reduce the content of formaldehyde in the binder, the vapours of which are toxic and even carcinogenic to the human body. One of the technologically simplest solutions could be the incorporation of another bio-based wood composite binder into the completed industrial PFR. In turn, birch outer bark suberinic acids are an effective, ecological, thermosetting binder to produce mechanically durable and moisture-resistant wood composites. The aim of the study was to adapt the components of birch outer bark (suberinic acids and betulin-based extractives) for their incorporation into industrial PFR and to find the optimal degree of resins replacement in practical experiments. At the same time, to keep a similar level of the bending strength and moisture resistance (shear strength) of the plywood bonded with the modified binder compared to pure industrial PFR. As a result, it was found that it was possible to replace up to 30 wt% (dry basis) of the industrial PFR with birch outer bark components to obtain birch plywood without significant loss of the bending strength and moisture resistance. In this way, it would be possible to significantly reduce the carbon footprint of the synthetic PFR binder in the birch plywood industry by using birch processing residues.

Abstract: The effects on birch outer bark (BOB) ethanolic extractives’ chemical composition after recrystallization with C2–C5 alkanols were studied in this paper. Ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, and 1-pentanol were used as solvents. The solubility of BOB extractives at the solvents boiling point was determined empirically. It was found that, with an increase of the boiling point of the solvents, the solubility of the extractives increased, reaching up to 486 g/L in 1pentanol at 142.2 °C. Recrystallization yields reached up to 67 wt% using 2-butanol and the purity of betulin up to 96 wt% using 2‐propanol as a solvent. Considering the yield of recrystallization, betulin content, boiling point of the solvent, solvent loss, toxicity and eco-friendliness of the solvent, ethanol was chosen to be the most suitable solvent for industrial scale purification of betulin in the BOB extractives. Using only one recrystallization step the content of betulin was increased by 20% — from 75 to 95 wt% and the yield of recrystallization was 32.1 g per liter of solvent.

Abstract: Many chemicals are used to prolong wood lifetime and protect wood against wood-destroying organisms and fire but there is not sufficient information about their possible corrosive effects on wood and its structural components from the perspective of long-term exposition in unsuitable condition. This study evaluated the combined effects of inorganic chemicals (borates, phosphates containing ammonia, sulphates with metal cations, chlorides) and wet-thermal accelerated ageing (T=80 °C, RH=65 %, for 30 days) on chemical composition of treated wood. Used analyses indicated that selected chemicals cause a decomposition of all wood constituents in varying degrees. Cellulose was degraded in the greatest extent due to acidic sulphates (Fe³⁺, Cu²⁺) and almost no deterioration of polysaccharides was caused with H₃BO₃. A negative effect on lignin had almost only Na₂B₄O₇.10H₂O and NaCl. At the same time the amount of extractives in hot water and acetone and ash content were compared at all samples. The wet-thermal ageing played an important role in wood degradation, but the effect of chemical treatment was certainly stronger.

Abstract: Samples prepared from oak (Quercus robur L.) wood were exposed to heat treatment at temperatures of 160, 180, 200 and 220 oC for 3, 6, 9 and 12 hours. In both untreated and thermally treated wood there were determined extractives and lignin by National Renewable Energy Laboratory (NREL) procedures, cellulose by Seifert's method, holocellulose according to Wise, hemicelluloses as difference between holocellulose and cellulose. Monosaccharides were determined by high performance liquid chromatography (NREL).The results show that hemicelluloses are less stable at thermal treatment than cellulose. The amounts of lignin and extractives rose by increasing both temperature and time of the treatment while the amounts of hemicelluloses decreased. Thermal treatment also resulted in significant decreases of the yields of non-glucosic saccharides. Degradation of carbohydrates can cause the deterioration of mechanical properties of wood.

Abstract: In order to learn of pyrolytic behavior of wheat straw multifunctional materials, the extractives of wheat straw biomass were adsorbed and determined by Py-GC-MS. And the main constituents were stigmasterol, vitamin e, campesterol, .gamma.-sitosterol, stigmasterol, 22,23- dihydro-, nonacosane, stigmastan-3,5,22-trien, heneicosane, lup-20(29)-en-3-one, 1,2- benzenedicarboxylic acid, buty l 2-methylpropyl ester, stigmast-4-en-3-one, stigmastan-3,5-diene, 4,22-stigmastadiene-3-one, cholest-5-en-3-ol (3.beta.)- , pyridine-3-carboxamide, oxime, etc.

Abstract: In order to mold preservation to bamboo, the effect of the extractives from 28 tree leaves on bamboo biology mildewing was studied basing on full-factor test. The result was as follows: (1) The inhibition rate became lower for steam time longer. (2) The effects of soaking time and boiling time were all small at steam time of 1h. And The effects of Cinnamomum camphora leaves were better than ones of Cedrus deodara leaves. (3) Soaking, water boiling and steaming had synergy mold preservation to bamboo by Cinnamomum camphora tree root, Cinnamomum camphora leaves and Cedrus deodara leaves.

Abstract: In order to find out its active behavior, the extractives of wheat straw biomass were adsorbed and determined by Py-GC-MS. And the main constituents were eicosane, stigmasterol, 22,23-dihydro-, .gamma.-sitosterol, stigmasterol, campesterol, nonacosane, stigmast-4-en-3-one, lup-20(29)-en-3-one, 13-tetradecen-1-ol acetate, 1,3-butadiene, 2- methyl-, 9-octadecenoic acid, (e)-, acetic acid, stigmast-5-en-3-ol, oleate, 1-nonadecene, heptacosane, 4,22-stigmastadiene-3-one, 4-((1e)-3-hydroxy-1-propenyl)-2- methoxyphenol, 1-heptene, 2-isohexyl-6-methyl-, etc.

Abstract: In order to find out its active materials, the extractives of wheat straw biomass were adsorbed and determined by Py-GC-MS. And the main constituents were 1-phenanthrenecarboxylic acid, 1,2,3,4,4a,9,10,10a-octahydro-1,4a-dimethyl-7-(1-methylethyl)- (31.32%), 1,3-pentadiene,(z)- ( 4.5%), cyclobutene(2.17%), 1-nonadecene(2.12%), etc.

Abstract: In order to evaluate its potential health risk to food, Py-GC/MS was used to analyze the high-grade resource recovery of benzene/ethanol extractives of the Cinnamomum camphora wood. Relative content of each component was determined by area normalization. The main constituents were hexadecanoic acid, oleic Acid, octadecanoic acid, 4-chloro-2-fluoroaniline, cyclohexane, 1,1-dimethyl-, 7-heptadecene, 17-chloro-, brucine, ergosta-4,6,22-trien-3.beta.-ol, etc. So the benzene/ethanol extractives of Cinnamomum camphora could be used as materials of biomedicine.

Abstract: The extractives of bamboo leaves were extracted and determined by Py-GC-MS. And the main constituents of extractives were tritriacontane(4.84%), 9-octadecyne(4.19%), ethyl alcohol(3.23%), 2-furanmethanamine, tetrahydro-(3.1%), .beta.-sitosterol acetate(2.84%), vitamin e(2.77%), triacontanoic acid, methyl ester(2.67%), .gamma.-sitosterol(2.33%), pyridine-3-carboxamide, oxime, n-(2-trifluoromethyl -phenyl)-(2.32%), nonacosane(2.15%), etc.