Mikro/nano selüloz üretiminde enzimatik ön muamelenin etkisi
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Dosyalar
Tarih
2017
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Düzce Üniversitesi
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Mikrofibril (MFC) ve nanofibril (NFC) selülozun endüstriyel uygulamaları bir süredir kullanılmaktadır, ancak üretim aşamalarının geliştirmesine ve aynı zamanda yüksek kalitede ürünler elde edilmesine ihtiyaç vardır. Bu çalışmanın amacı, ön muamele aşamalarında kullanılan enzimlerin (Pulpzyme HC 2500 ve Celluclast 1.5 L) incelenmesiyle mikrofibril ve nanofibril selülozun üretim verimliliğini ve kalitesini artırmaktır. MFC ve NFC kırmızı sakız ağacından (Eucalyptus camaldulensis) elde edilen kraft hamuru ile üretilmiştir. Enzimatik hidroliz, mekanik kesme ve yüksek basınçlı homojenizasyon işlemi ile birleştirilmiştir. Üretilen NFC ve MFC'ler HPLC, FTIR, TGA ve 13C-NMR ile karakterize edilmiştir. Morfolojik ve viskoelastik özellikleri sırasıyla SEM ve reometre ile incelenmiştir. Celluclast 1.5 L enziminin kullanılması, amorf selülozda seçici hidrolize neden olmuş ve yüksek en boy oranına sahip nano ölçekli selüloz gözlenmiştir. 35 ± 12 nm genişliğine sahip oldukça homojen bir NFC bu çalışmada üretilmiştir. MFC ve NFC üretilmesi için kullanılan aşamalar ağartılmış kraft hamurunun selüloz kristalinitesini düşürmüş ve FTIR sonuçları incelendiğinde, toplam kristalin indeks (TCI) ve yanal düzenlilik indeks (LOI) değerlerinin düştüğü gözlenmiştir. Düşük kristallik 13C-NMR (46.2 ppm) tarafından da belirlenmiş olup bu sonuç amorf bölgedeki C6 pikleriyle desteklenmiştir. Ayrıca MFC ve NFC yapıları, daha düşük termal bozunmaya neden olan kısa boyutlu yapılar olarak gözlenmiştir. Sonuç olarak, mevcut ön muameleler sonucunda elde edilen MFC ve NFC yapılarının fizikokimyasal özellikleri geliştirilmiştir.
Industrial applications of microfibrillated (MFC) and nanofibrillated cellulose (NFC) have been in use for some time; however, there is a need to improve the production steps and at the same time to obtain better quality products. The aim of this study was to improve the production efficiency and quality of MFC and NFC by examining the enzymes (Pulpzyme HC 2500 and Celluclast 1.5 L) employed in pretreatment sequences. NFC and MFC were generated kraft pulp, produced from red gum tree plant (Eucalyptus camaldulensis). Enzymatic hydrolysis was combined with mechanical shearing and high-pressure homogenization. The generated NFC and MFC were characterized by HPLC, FTIR, TGA and 13C-NMR. Morphological and viscoelastic properties were investigated with SEM and Rheometer, respectively. Results indicated that using Celluclast 1.5 L caused selective hydrolysis in amorphous cellulose and produced high aspect ratio nanoscale cellulose elements. A fairly homogeneous NFC with a width of 35 ± 12 nm was produced in this study. Employed treatments to produce MFC and NFC decreased the cellulose crystallinity of bleached kraft pulp and lower total crystalline index (TCI) and lateral order index (LOI) values were observed for MFC and NFC in FTIR examinations. Lower crystallinities were also defined by 13C-NMR (46.2 ppm), which was substantiated with C6 peaks in the amorphous domain. Obtained MFC and NFC revealed shorter fiber dimensions with less ordered cellulose structure causing lower thermal degradation. Consequently, the methods examined in this study produced MFC and NFC with improved physicochemical and structural properties.
Industrial applications of microfibrillated (MFC) and nanofibrillated cellulose (NFC) have been in use for some time; however, there is a need to improve the production steps and at the same time to obtain better quality products. The aim of this study was to improve the production efficiency and quality of MFC and NFC by examining the enzymes (Pulpzyme HC 2500 and Celluclast 1.5 L) employed in pretreatment sequences. NFC and MFC were generated kraft pulp, produced from red gum tree plant (Eucalyptus camaldulensis). Enzymatic hydrolysis was combined with mechanical shearing and high-pressure homogenization. The generated NFC and MFC were characterized by HPLC, FTIR, TGA and 13C-NMR. Morphological and viscoelastic properties were investigated with SEM and Rheometer, respectively. Results indicated that using Celluclast 1.5 L caused selective hydrolysis in amorphous cellulose and produced high aspect ratio nanoscale cellulose elements. A fairly homogeneous NFC with a width of 35 ± 12 nm was produced in this study. Employed treatments to produce MFC and NFC decreased the cellulose crystallinity of bleached kraft pulp and lower total crystalline index (TCI) and lateral order index (LOI) values were observed for MFC and NFC in FTIR examinations. Lower crystallinities were also defined by 13C-NMR (46.2 ppm), which was substantiated with C6 peaks in the amorphous domain. Obtained MFC and NFC revealed shorter fiber dimensions with less ordered cellulose structure causing lower thermal degradation. Consequently, the methods examined in this study produced MFC and NFC with improved physicochemical and structural properties.
Açıklama
YÖK Tez No: 456316
Anahtar Kelimeler
Kimya, Chemistry, Mühendislik Bilimleri, Engineering Sciences
