Synthesis of a novel acrylated abietic acid-g-bacterial cellulose hydrogel by gamma irradiation

• Acrylated AbA and acrylated AbA-g-bacterial cellulose hydrogel are formed by free-radical dimerization and grafting.
• Abietic acid controls the degree of swelling and gel fraction of the hydrogel.
• CP/MAS 13C solid state NMR provides the key to understand the chemical composition of the hydrogel.
• Cell viability tests prove the combination to be safe for future biomedical applications.

Acrylated abietic acid (acrylated AbA) and acrylated abietic acid-grafted bacterial cellulose pH sensitive hydrogel (acrylated AbA-g-BC) were prepared by a one-pot synthesis. The successful dimerization of acrylic acid (AA) and abietic acid (AbA) and grafting of the dimer onto bacterial cellulose (BC) was confirmed by 13C solid state NMR as well as FT-IR. X-ray diffraction analysis showed characteristic peaks for AbA and BC; further, there was no effect of increasing amorphous AA content on the overall crystallinity of the hydrogel. Differential scanning calorimetry revealed a glass transition temperature of 80 °C. Gel fraction and swelling studies gave insight into the features of the hydrogel, suggesting that it was suitable for future applications such as drug delivery. Scanning electron microscopy observations showed an interesting interpenetrating network within the walls of hydrogel samples with the lowest levels of AA and gamma radiation doses. Cell viability test revealed that the synthesized hydrogel is safe for future use in biomedical applications.