Effect of sodium borohydride on Populus tremula L. Kraft pulping

Sodium borohydride (NaBH4) added kraft pulping was performed using European aspen (Populus tremula L.) chips and the effects of the NaBH4 addition on the physical and optical properties of pulps and resultant papers were investigated. | Turk J Agric For 32 (2008) 131-136 © TÜB‹TAK Effect of Sodium Borohydride on Populus tremula L. Kraft Pulping Abdullah ‹STEK*, ‹hsan ÖZKAN Zonguldak Karaelmas University, Bart›n Forestry Faculty, Department of Forest Product Industry, 74100 Bart›n - TURKEY Received: Abstract: Sodium borohydride (NaBH4) added kraft pulping was performed using European aspen (Populus tremula L.) chips and the effects of the NaBH4 addition on the physical and optical properties of pulps and resultant papers were investigated. In order to determine the optimum cooking parameters, 6 different laboratory experiments were carried out, which indicated that 2 cooking conditions were better than the others. The effects of 1%, 2%, and 3% NaBH4 additions on pulps and paper properties were investigated based on these 2 cooking conditions. It was noted that the increasing level of NaBH4 added improved the screened pulp yield and pulp viscosity levels and reduced the Kappa number. There was no statistical significance regarding the strength properties of kraft-NaBH4 pulps compared to control pulps at 50 ± 3 °SR freeness level. However, the brightness of handsheets was increased by NaBH4 additions. Key Words: Populus tremula L., kraft pulping, sodium borohydride, screened yield, paper properties Titrek Kavak (Populus tremula L.) Kraft Hamuru Üretimine Sodyum Borhidrürün Etkisi Özet: Bu çal›flmada, titrek kavak (Populus tremula L.) odunlar›ndan sodyum borhidrür (NaBH4) ilaveli kraft yöntemiyle k⤛t hamuru üretilmifl ve NaBH4’ün hamur verimi ve k⤛d›n fiziksel ve optik özellikleri üzerine etkisi incelenmifltir. Optimum piflirme parametrelerin belirlemek için 6 adet ön deneme piflirmesi yap›lm›flt›r. Bu piflirmelerden en yüksek verim ve en düflük Kappa numaras› elde edilen 2 piflirme flartlar› k›lavuz olarak seçilmifltir. Bu k›lavuz piflirme koflullar›na %1–2–3 oran›nda NaBH4 ilave edilerek 6 adet daha piflirme yap›lm›flt›r. ‹lave edilen NaBH4 oran›na ba¤l› olarak, hamur verimi ve viskozitesinin .