Competition between (flow-induced) crystallization and Diels-Alder crosslinking

The study of the competition between flow-induced crystallization and Diels-Alder crosslinking, where both phenomena have distinctively different time scales. DA crosslinking, which is typically a very fast process, is studied by the chemical modification of existing polymers (poly-e-caprolactone PCL) by means of Differential Scanning Calorimetry (DSC) and Thermogravimetrical Analysis (TGA). The speed of the crystallization phenomena can be tuned depending on the designed polymers (molar masses) and by altering process parameters such as flow intensity, flow duration, and the cooling time. Insights from the competition of time scales of DA crosslinking and crystallization is used to create specific structures in polymer processing operations. The incorporation of DA crosslinking with the flow-induced crystallization can lead to the reduction of anisotropic structures resuliting from flow-induced crystallization. The materials with enhanced properties (e.g. stiffness) and solvent resistance without losing reprocessability. Two polymer processing operations will be used, namely slit die extrusion and small scale Laser Sintering experiments (3D printing). The slit die extrusion allows to create solidified slits that will be used to determine the mechanical properties to probe the combined effect of crosslinking and crystallization. The usage of functionalised PCL powder in the Laser Sintering experiment will under the correct conditions improve the interfacial adhesion by means of an interfacial crosslinking reaction.