Determination of weathering effects on chemical properties of pine (Pinus sylvestris L.) and chestnut (Castanea sativa Mill.)

Chestnut (Castanea sativa Mill.) and Scots pine (Pinus sylvestris L.) were found appropriate for the thesis as these species used outdoor widely. Samples were prepared in the dimensions of 15.0 x 7.5 x 1.0 cm and were exposed outdoor on panels constructed at a gradient of 45° southwards for periods of 3, 6, 12 and 24 months. At the end of each period chemical changes on the 1 mm depth surface were analyzed detailed. Macromolecular substances (like cellulose and lignin) and extractives (e.g. solubilities, lipophilics and hydrophilics) were determined by analytical methods (GC and GC-MS).Smooth and rough surface samples of same species were generally evaluated, results on chemical analyses show similarity, otherwise, differences were determined on the amounts of lipophilic and hydrophilic analyses.According to chemical analysis results of main components of cell membranes, the rate of ?-cellulose and lignin which were applied to both smooth and rough surface scots pine wood samples showed increasing tendency over months, on the other hand, the amount of holocellulose decreased significantly. On the both smooth and rough surface chestnut samples, the amount of holocellulose increased significantly, lignin rate also showed little increase and ?-cellulose rate decreased significantly.As a result of solubility experiments, hot water, 1% NaOH, hexane and acetone ?water solubility showed a general increase despite a general decrease of cold water solubility on the rough and smooth surface of scots pine samples. On the other hand, 1% NaOH and hexane solubility showed a general increase, a general decrease was determined on hot water, cold water and acetone-water solubility levels on the smooth and rough surfaces of chestnut samples.Total amount of identified lipophilics in smooth an rough surface scots pine samples were decreased over months. Resin acids and fatty acids are forming the constituent of lipophilics. The highest mean amount of resin acids was as 17,21 mg/g at 12th month and the lowest at 3rd month as 8.02 mg/g on smooth samples of scots pine. On the rough surface samples of scots pine, the highest and lowest values of resin acids were 20,04 mg/g (6th month) and 11,03 mg/g (3rd month), respectively. Fatty acid values of smooth surface scots pine samples were the highest at 6th month as 2,46 mg/g and the lowest at 3rd month as 1,60 mg/g. The highest amount of fatty acids in rough scots pine samples was determined as 3,35 mg/g at 6th month despite the lowest as 1,31 mg/g at 24th month. In addition, the most abundant resin acid in smooth scots pine samples was dehydroabietic acid with 7,24 mg/g after 12 month weathering. The highest fatty acid was determined as oleic acid on rough surface scots pine samples as 1,67 mg/g at 6th month. The amount of fatty acids in chestnut wood samples has a general increasing tendency. The highest value was 0,19 mg/g (3rd month) and the lowest was 0,06 mg/g (6th month) for smooth surface chestnut samples. Also, lignoceic acid was the most abundant fatty acid which has 0,19 mg/g value on smooth surface chestnut samples after 12 months.Sugars and phenolic compounds are forming the constituent of hydrophilic compounds. The amount of sugar in smooth and rough scots pine and chestnut wood samples showed a general decrease over months. Also, monomethylpinosylvin was determined the highest hydrophilic matter in the 1,83 mg/g amount at 6th month on rough scots pine samples.