Comparison of mechanical reinforcement effects of surface-modified cellulose nanofibrils and carbon nanotubes in PLLA composites
详细信息 查看全文
- 作者：Shuji Fujisawa ; Tsuguyuki Saito ; Satoshi Kimura ; Tadahisa Iwata ; Akira Isogai
- 关键词：A. Nanocomposites ; A. Carbon nanotubes ; B. Interface ; B. Mechanical properties
- 刊名：Composites Science and Technology
- 出版年：10 January, 2014
- 年：2014
- 卷：90
- 期：Complete
- 页码：96-101
- 全文大小：1764 K
文摘
Cellulose nanofibrils were prepared using 2,2,6,6-tetramethylpiperidiniyl-1-oxyl (TEMPO)-mediated oxidation of wood cellulose, and the surfaces of the resulting TEMPO-oxidized cellulose nanofibrils (TOCNs) were grafted with amine-terminated polyethylene glycol (PEG) chains via ionic bonds. PEG-TOCN/PLLA composite films were prepared by casting mixtures of various ratios of PEG-TOCN/chloroform dispersion and PLLA/chloroform solution. The mechanical reinforcement properties of PEG-TOCNs prepared using PEG-NH2 of two different PEG chain lengths were evaluated using tensile tests and compared against those of PEG-grafted single-walled carbon nanotubes (PEG-SWCNT). PEG-TOCNs were individually dispersed in the PLLA matrix so that the Young鈥檚 modulus increased with PEG-TOCN content, following theoretically predicted values. In contrast, the PEG-SWCNT formed aggregates in the PLLA matrix, probably owing to heterogeneous distribution of carboxyl groups. As a result, PEG-TOCN/PLLA composites showed superior properties to those of PEG-SWCNT/PLLA composites in terms of optical transparency, strength, and toughness.