Cotton‐fabric‐grafted poly( N ‐isopropyl acrylamide) initiated by ammonium peroxydisulfate

In this article, we report that thermoresponsive poly( N ‐isopropyl acrylamide) (PNIPAAm) was successfully grafted onto a cotton fabric (CF) surface by free‐radical solution grafting polymerization; we obtained a thermoresponsive CF‐grafted PNIPAAm. This reaction system only contained four constituents: the monomer, solvent, initiator, and CFs. Ammonium peroxydisulfate was chosen as the initiator, and water was chosen as the solvent. A series of initiator concentrations and grafting polymerization temperatures were used in the experiments, and their effects on the grafting ratio ( G ) were also studied. Also, the effects of the G of CF‐ g ‐PNIPAAm on their corresponding thermoresponses was studied further. The structure of CF‐ g ‐PNIPAAm was characterized by Fourier transform infrared spectroscopy–attenuated total reflectance analysis and scanning electron microscopy analysis. The G of CF‐ g ‐PNIPAAm was measured by a gravimetric method. The thermoresponse of CF‐ g ‐PNIPAAm was characterized by modulated differential scanning calorimetry, water contact angle measurements, and wetting time measurements. The experiments manifested the following results: (1) the initiator concentration and grafting polymerization temperature both influenced G, (2) the grafted PNIPAAm covered the CF surface, (3) the CF‐ g ‐PNIPAAm showed thermoresponsive hydrophilicity/hydrophobicity, and (4) a relationship existed between the thermoresponse of CF‐ g ‐PNIPAAm and the corresponding G . © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131 , 41193.