What is more, cross-linking occurs immediately when the optimal reaction time (115 min) is slightly exceeded. In the literature for cross-linking, there is often a need to use a high temperature and vacuum for 24 hours or even longer. Because of all these arguments, catalysed synthesis has a much bigger potential for industrial application than the most popular synthesis performed in literature, which is much longer and gives a polymer that is hard to cross-link. A DSC experiment (Figure ) was performed to determine the thermal properties of the obtained prepolymer. Analysis of the first curve reveals a broad endothermic effect spanning a temperature range of approximately -20 °C to 80 °C. Analysis of the first curve shows a broad, multimodal endothermic effect over a temperature range of approximately -20 °C to 80 °C. The total enthalpy of melting, determined based on this curve, is approximately 67.0 J/g. Dividing it into three distinct effects gives enthalpy values of 35.0 J/g, 20.9 J/g, and 11.1 J/g, corresponding to peak maxima at 8.2 °C, 32.3 °C, and 56.2 °C, respectively. The presence of this effect indicates a high degree of ordering in the prepolymer structure after synthesis, which corresponds to its high crystallinity. In turn, the multimodal nature of the observed effect is characteristic of PGS prepolymers and is often attributed to the wide dispersion of molecular weights in the product prior to the cross-linking step. During the cooling cycle of the measurement, a narrow exothermic effect with a maximum at approximately 0.1°C was observed, indicating polymer crystallization. This suggests the continued high mobility of the PGS polymer chains and the absence of strong cross-linking between them. The curve recorded during the second heating scan differs from that observed during the first. This difference may result from two factors: 1) the removal of the thermal history of the synthesized polymer during the initial heating, and 2) structural changes that occurred during this heating (conducted up to 200°C), such as cross-linking, post-reaction processes, or the evaporation of structural water. Firstly, the second scan allowed the determination of the glass transition temperature (Tg = -25.9°C) of the amorphous fraction of the material, which was not possible in the previous scan due to the significant presence of the crystalline phase and the absence of a visible inflexion in the curve. In addition, the endothermic effects associated with the melting of the material decreased and shifted towards lower temperatures. The total melting enthalpy was approximately 35.2 J/g, and when divided into individual effects, the values were 18.5 J/g, 6.4 J/g, 8.8 J/g, and 1.5 J/g, with peak maxima at 0.4 °C, 15.5 °C, 38.9 °C, and 49.7 °C, respectively.