Hydrophobic Modification of Nanocellulose via a Two-Step Silanation Method

• Main Authors: Wensheng Lin, Xiaoyong Hu, Xueqing You, Yingying Sun, Yueqin Wen, Wenbin Yang, Xinxiang Zhang, Yan Li, Hanxian Chen
• Format: Article
• Language: English
• Published: MDPI AG 2018-09-01
• Series: Polymers
• Subjects: nanocellulose; hydrophobicity; dodecyltrimethoxysilane; silanation; KH560
• Online Access: http://www.mdpi.com/2073-4360/10/9/1035
• ISSN: 2073-4360

Dodecyltrimethoxysilane (DTMOS), which is a silanation modifier, was grafted onto nanocellulose crystals (NCC) through a two-step method using KH560 (ɤ-(2,3-epoxyproxy)propytrimethoxysilane) as a linker to improve the hydrophobicity of NCC. The reaction mechanism of NCC with KH560 and DTMOS and its surface chemical characteristics were investigated using Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and HCl–acetone titration. These analyses confirmed that KH560 was grafted onto the surface of NCC through the ring-opening reaction, before DTMOS was covalently grafted onto the surface of NCC using KH560 as a linker. The grafting of NCC with DTMOS resulted in an improvement in its hydrophobicity due to an increase in its water contact angle from 0° to about 140°. In addition, the modified NCC also possessed enhanced thermal stability.