Cellulose nanofibers from the skin of beavertail cactus, Opuntia basilaris, as reinforcements for polyvinyl alcohol

In this study, the skin of the beavertail cactus, Opuntia Basilaris, was used for the isolation of cellulose nanofibers using a chemo-mechanical technique. It was shown that the skins had a relatively high cellulose content, whereas their lignin content was low. Fourier transform infrared spectroscopy and X-ray diffraction proved that the isolation of cellulose nanofibers from the amorphous components of the skins was performed successfully. The cactus skins were also shown to have a high content of calcium oxalate crystals. Morphological observations proved that the isolated cellulose fibers had diameters in the range of 10-50 nm. It was shown that the addition of nanofibers increased the modulus and strength of the polyvinyl alcohol matrix significantly, whereas the elongation at break decreased. Thermogravimetric analysis proved that: (i) isolated nanofibers had higher thermal stabilities than the cactus skins, and (ii) inclusion of nanofibers increased the stability of polyvinyl alcohol noticeably. (c) 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42499.