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Effects of adding different boron compounds to the urea-formaldehyde resin were evaluated relative to the physical, mechanical, and other properties of medium-density fiberboard (MDF). While the chemical addition of boric acid to the urea-formaldehyde resin increased the modulus of rupture and modulus of elasticity values of MDF boards, the physical and chemical additions of other boron compounds decreased those values. While there were no significant decreases in internal bond values, the chemical addition of boric acid and borax decahydrate to urea-formaldehyde resin increased the internal bond values of MDF boards. It was observed that in both types of addition, borax pentahydrate reduced the formaldehyde emission values of MDF boards the most and also reduced the burnt area by up to 30%. When the type of addition of boron compounds to urea-formaldehyde was compared, the addition of boron compounds at the resin formation stage showed better results in the properties of MDF boards than physical addition.

Effects of adding different boron compounds to the urea-formaldehyde resin were evaluated relative to the physical, mechanical, and other properties of medium-density fiberboard (MDF). While the chemical addition of boric acid to the urea-formaldehyde resin increased the modulus of rupture and modulus of elasticity values of MDF boards, the physical and chemical additions of other boron compounds decreased those values. While there were no significant decreases in internal bond values, the chemical addition of boric acid and borax decahydrate to urea-formaldehyde resin increased the internal bond values of MDF boards. It was observed that in both types of addition, borax pentahydrate reduced the formaldehyde emission values of MDF boards the most and also reduced the burnt area by up to 30%. When the type of addition of boron compounds to urea-formaldehyde was compared, the addition of boron compounds at the resin formation stage showed better results in the properties of MDF boards than physical addition.

Abstract In this study, oyster (Pleurotus ostreatus) mushroom was cultivated from hazelnut branches (HB) (Corylus avellana L.), hazelnut husk (HH), wheat straw (WS), rice husk (RH) and spent coffee grounds (CG). Hazelnut branch waste was used for the first time in oyster mushroom cultivation. In the study, mushrooms were grown by preparing composts from 100 to 50% mixtures of each waste type. Yield, biological activity, spawn run time, total harvesting time and mushroom quality characteristics were determined from harvested mushroom caps. In addition, chemical analysis of lignocellulosic materials (extractive contents, holocellulose, α-cellulose, lignin and ash contents) were carried out as a result of mushroom production and their changes according to their initial amounts were examined. In addition, the changes in the structure of waste lignocellulosic materials were characterized by FTIR analysis. As a result of the study, 172 g/kg yield was found in wheat straw used as a control sample, while it was found as 255 g/kg in hazelnut branch pruning waste. The highest spawn run time (45 days) was determined in the compost prepared from the mixture of hazelnut husk and spent coffee ground wastes. This study showed that HB wastes can be used for the cultivation of oyster mushroom (P. ostreatus). After mushroom cultivation processes, holocelulose and α-cellulose content rates decreased while ash contents increased. FTIR spectroscopy indicated that significant changes occurred in the wavelengths regarding cellulose, hemicellulose and lignin components. Most significant changes occurred in 1735, 1625, 1510, 1322 and 1230 wavelengths.