Received: 1 November 2022 Accepted: 19 January 2023
Abstract:
Shape memory polymers are smart materials that have the thermo-/chemo-responsive shape memory effect, can react to environmental stimuli, and exhibit excellent shape-fixity, shape-recovery and folding/unfolding effects. This type of shape memory polymer has shown great potential in the design and development of various drug delivery systems/devices. However, they have some intrinsic shortcomings, such as biodegradability, slow response rate, poor encapsulation ability of hydrophobic/hydrophilic drugs etc. These phenomenon sometimes limit their application in developing suitable drug delivery systems. In this study, we synthesized and characterized a poly(n-isopropyl acrylamide-4-acryloyloxy benzophenone) i.e., p(NIPAM-4ABP) based thermo-responsive self-folding shape-memory polymer with an excellent shape-memory behavior. The lower critical solution temperature of the synthesized p(NIPAM-4ABP) was determined using dynamic light scattering analysis to determine the effect of the addition of 4-ABP to the pNIPAM network. Fourier-transform infrared spectroscopy (FT-IR) was used to understand the reversibility of the shape-memory mechanism of the synthesized feedstock. A swelling study in different solvents was performed as a driving force to further encapsulate the drug molecules into p(NIPAM-4ABP) network. Finally, the shape memory behavior of this synthesized polymer was established via converted it into p(NIPAM-4ABP) feedstock to validate the excellent shape memory features.