Temperature-responsive N-isopropylacrylamide-grafted natural rubber

Abstract

Temperature-responsive polymers are smart materials that respond to changes in temperature and have a wide range of applications, ranging from sensing to biomedical fields. In this work, we investigated the synthesis and temperature-responsive behavior of responsive elastomer based on N-isopropylacrylamide-grafted natural rubber. The grafting reaction was carried out using deproteinized natural rubber (DPNR) latex and potassium persulfate as free radical initiator. The temperature responsiveness of the graft copolymers was investigated using water swelling and contact angle measurements, and compared with that of pure DPNR. The lower critical solution temperature of the graft copolymer was found to be in the range 30–34 °C, whereas the DPNR was not responsive to temperature. Furthermore, the graft copolymer exhibited temperature responsiveness in a solid state. As the temperature responsiveness of the graft copolymer is close to the human body temperature, it can be used in biomedical applications. Dye adsorption studies revealed the Langmuir isotherm, indicating monolayer coverage. The technique proposed in this study produces a temperature-responsive natural rubber, with potential applications as a responsive material for use in sensing and biomedical products.