TY - JOUR
T1 - Dry, hydrophobic microfibrillated cellulose powder obtained in a simple procedure using alkyl ketene dimer
AU - Yan, Yutao
AU - Amer, Hassan
AU - Rosenau, Thomas
AU - Zollfrank, Cordt
AU - Dörrstein, Jörg
AU - Jobst, Cornelia
AU - Zimmermann, Tanja
AU - Keckes, Jozef
AU - Veigel, Stefan
AU - Gindl-Altmutter, Wolfgang
AU - Li, Jianzhang
N1 - Publisher Copyright:
© 2016, The Author(s).
PY - 2016/4/1
Y1 - 2016/4/1
N2 - In order to produce dry and hydrophobic microfibrillated cellulose (MFC) in a simple procedure, its modification with alkyl ketene dimer (AKD) was performed. For this purpose, MFC was solvent-exchanged to ethyl acetate and mixed with AKD dissolved in the same solvent. Curing at 130 °C for 20 h under the catalysis of 1-methylimidazole yielded a dry powder. Scanning electron microscopy of the powder indicated loss in nanofibrillar structure due to aggregation, but discrete microfibrillar structures were still present. Water contact angle measurements of films produced from modified and unmodified MFC showed high hydrophobicity after AKD treatment, which persisted even after extraction with THF for 8 h. The hydrophobized MFC was characterized by Fourier transform infrared spectroscopy, nuclear magnetic resonance and X-ray analysis. In summary, strong indications for the presence of AKD on the surface of MFC before and after extraction with solvent were found, but only a very small amount of covalent β-ketoester linkages between the modification agent and cellulose was revealed.
AB - In order to produce dry and hydrophobic microfibrillated cellulose (MFC) in a simple procedure, its modification with alkyl ketene dimer (AKD) was performed. For this purpose, MFC was solvent-exchanged to ethyl acetate and mixed with AKD dissolved in the same solvent. Curing at 130 °C for 20 h under the catalysis of 1-methylimidazole yielded a dry powder. Scanning electron microscopy of the powder indicated loss in nanofibrillar structure due to aggregation, but discrete microfibrillar structures were still present. Water contact angle measurements of films produced from modified and unmodified MFC showed high hydrophobicity after AKD treatment, which persisted even after extraction with THF for 8 h. The hydrophobized MFC was characterized by Fourier transform infrared spectroscopy, nuclear magnetic resonance and X-ray analysis. In summary, strong indications for the presence of AKD on the surface of MFC before and after extraction with solvent were found, but only a very small amount of covalent β-ketoester linkages between the modification agent and cellulose was revealed.
KW - Alkyl ketene dimer
KW - Dry powder
KW - Hydrophobicity
KW - Microfibrillated cellulose
KW - Surface modification
UR - http://www.scopus.com/inward/record.url?scp=84958757798&partnerID=8YFLogxK
U2 - 10.1007/s10570-016-0887-0
DO - 10.1007/s10570-016-0887-0
M3 - Article
AN - SCOPUS:84958757798
SN - 0969-0239
VL - 23
SP - 1189
EP - 1197
JO - Cellulose
JF - Cellulose
IS - 2
ER -