Poly(glycidyl methacrylate)/bacterial cellulose nanocomposites: Preparation, characterization and post-modification

Nanocomposites composed of poly(glycidyl methacrylate) (PGMA) and bacterial cellulose (BC) were prepared by the in-situ free radical polymerization of glycidyl methacrylate (GMA) inside the BC network. The resulting nanocomposites were characterized in terms of structure, morphology, water-uptake capacity, thermal stability and viscoelastic properties. The three-dimensional structure of BC endowed the nanocomposites with good thermal stability (up to 270 degrees C) and viscoelastic properties (minimum storage modulus = 80 MPa at 200 degrees C). In addition, the water-uptake and crystallinity decreased with the increasing content of the hydrophobic and amorphous PGMA matrix. These nanocomposites were then submitted to post-modification via acid-catalysed hydrolysis to convert the hydrophobic PGMA into the hydrophilic poly(glyceryl methacrylate) (PGOHMA) counterpart, which increased the hydrophilicity of the nanocomposites and consequently improved their water uptake capacity. Besides, the post-modified nanocomposites maintained a good thermal stability (up to 250 degrees C), viscoelastic properties (minimum storage modulus = 171 MPa at 200 degrees C) and porous structure. In view of these results, the PGMA/BC nanocomposites can be used as functional hydrophobic nanocomposites for post modification reactions, whereas the PGOHMA/BC nanocomposites might have potential for biomedical applications requiring hydrophilic, swellable and biocompatible materials. (C) 2019 Elsevier B.V. All rights reserved.