Synthesis of pH‐responsive crosslinked poly[styrene‐<i>co</i>‐(maleic sodium anhydride)] and cellulose composite hydrogel nanofibers by electrospinning

Abstract

Abstract BACKGROUND: Stimuli‐sensitive materials show enormous potential in the development of drug delivery systems. But the low response rate of most stimuli‐sensitive materials limits their wider application. We propose that electrospinning, a technique for the preparation of ultrafine fibrous materials with ultrafine diameters, may be used to prepare materials with a fast response to stimuli. RESULTS: Poly[styrene‐ co ‐(maleic sodium anhydride)] and cellulose (SMA‐Na/cellulose) hydrogel nanofibers were prepared through hydrolysis of precursor electrospun poly[styrene‐ co ‐(maleic anhydride)]/cellulose acetate (SMA/CA) nanofibers. In the presence of diethylene glycol, the SMA/CA composite nanofibers were crosslinked by esterification at 145 °C, and then hydrolyzed to yield crosslinked SMA‐Na/cellulose hydrogel nanofibers. These nanofibers showed better mechanical strengths and were pH responsive. Their water swelling ratio showed a characteristic two‐step increase at pH = 5.0 and 8.2, with the water swelling ratio reaching a maximum of 27.6 g g −1 at pH = 9.1. CONCLUSION: The crosslinked SMA‐Na hydrogel nanofibers supported on cellulose showed improved dimensional stability upon immersion in aqueous solutions. They were pH responsive. This new type of hydrogel nanofiber is a potential material for biomedical applications. Copyright © 2009 Society of Chemical Industry