Preparation and Characteristic of a Sodium Alginate/Carboxymethylated Bacterial Cellulose Composite with a Crosslinking Semi-Interpenetrating Network

A novel ionic crosslinking sodium alginate (SA)/carboxymethylated bacterial cellulose (CM-BC) composite with a semi-interpenetrating polymer network (semi-IPN) structure was developed in this study. The composite was prepared through the blending of an SA gel with CM-BC then crosslinking by Ca2+ followed by a freeze-drying process. Scanning electron microscopy showed the composite matrix organized in a three-dimensional network of CM-BC interpenetrated against SA molecular chains with a quantity of calcium alginate microspheres upon the surface. The swelling ratios of the composite were enhanced by 183, 198, and 212% with the supplementation of CM-BC weight fractions of 25, 50, and 75%, respectively; the swelling ratios changed with changing pH. The tensile modulus, tensile strength, and elongation at break of SA were enhanced by 165, 152, and 188%, respectively, with the addition of 50 wt % CM-BC. This study demonstrated that the semi-IPN structure dramatically changed the swelling and mechanical properties of the composite, and the semi-IPN will be a promising candidate for biomedical applications such as wound dressings and skin tissue engineering. (c) 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39848.