A Perspective on Modeling and Characterization of Transformations in the Blocky Nature of Olefin Block Copolymers

Traditional characterization methods are still unable to reveal the block structure of olefin block copolymers (OBCs). Therefore, when the predictability of our well-developed computer code (Mohammadi et al. Macromolecules, 2014, 47, 4778-4789) is extended, the blocky nature of OBCs is modeled and characterized. The expanded model could produce a diversity of macromolecules varying in the concentration of chain-shuttling agent, catalyst ratio, and monomer composition as key processing variables. The OBCs were screened and distinguished in view of chain-related specifics, i.e., chain length and chemical composition distribution, as well as block-related characteristics, i.e., number, length, and chemical composition of hard and soft blocks. A detailed picture of the blockiness was captured and visualized tracing transitions in the microstructure of copolymers, from the case corresponding to a blend copolymer (without any shuttling) to an OBC (with considerable shuttling) and then to random copolymers, reflecting the significance of the chosen parameters in determining the blockiness of OBCs.