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Four-dimensional printing is primarily based on the concept of 3D printing technology. However, it requires additional stimulus and stimulus-responsive materials. Poly-<i>N</i>-vinylcaprolactam is a temperature-sensitive polymer. Unique characteristics of poly-<i>N</i>-vinylcaprolactam -based hydrogels offer the possibility of employing them in 4D printing. The main aim of this study is to alter the phase transition temperature of poly-<i>N</i>-vinylcaprolactam hydrogels. This research focuses primarily on incorporating two additional monomers with poly-<i>N</i>-vinylcaprolactam: Vinylacetate and <i>N</i>-vinylpyrrolidone. This work contributes to this growing area of research by altering (increasing and decreasing) the lower critical solution temperature of <i>N</i>-vinylcaprolactam through photopolymerisation. Poly-<i>N</i>-vinylcaprolactam exhibits a lower critical solution temperature close to the physiological temperature range of 34–37 °C. The copolymers were analysed using various characterisation techniques, such as FTIR, DSC, and UV-spectrometry. The main findings show that the inclusion of <i>N</i>-vinylpyrrolidone into poly-<i>N</i>-vinylcaprolactam increased the lower critical solution temperature above the physiological temperature. By incorporating vinylacetate, the lower critical solution temperature dropped to 21 °C, allowing for potential self-assembly of 4D-printed objects at room temperature. In this case, altering the lower critical solution temperature of the material can potentially permit the transformation of the 4D-printed object at a particular temperature.