Proteus analysis

To determine the glass transition temperature T_g of the homopolymers and the statistical copolymers as well as the opening and closing process of the Diels-Alder crosslinked polymer networks, differential scanning calorimetry (DSC) was carried out using a DSC 204 F1 Phoenix (NETZSCH-Gerätebau GmbH, Selb, Germany). Furthermore, 10–15 mg polymer or crosslinked polymer were weighed into an aluminum crucible, slightly pressed, and then closed afterwards. The measurements were performed at 1 bar under nitrogen atmosphere (flow rate of 20 mL/min) in the temperature range between −80 °C (for n-butyl acrylate containing copolymers) or −20 °C and 200 °C. Heating and cooling rates were 5 °C/min. During the first heating interval, the thermal history of samples was erased by heating up the samples from −80 or −20 °C to 110 °C, followed by cooling them down to −80 or −20 °C. In the second and third interval, they were heated to 150 °C. After cooling down to −80 or −20 °C, in the fourth interval, they were heated to 200 °C. The thermal properties were analyzed using the DSC data of the second, third, and fourth heating. Data processing was performed by Proteus analysis (NETZSCH-Gerätebau GmbH, Selb, Germany).

Differential scanning calorimetry (DSC) analysis of the newly-developed films was performed using the DSC 204F1 differential scanning calorimeter (Phoenix Netsch, Selb, Germany). The samples were hermetically sealed in aluminium pans. Heating was performed at a rate of 10 °C/min within the temperature range of 25 to 300 °C. As a standard, an empty aluminium pan was used. The temperatures of enthalpy and thermal transition were calculated by means of computer software (Proteus Analysis, Netzsch GmbH, Selb, Germany) and enthalpy was expressed as J/g.