In-situ tracking polymer crystallization during film blowing by synchrotron radiation X-ray scattering: The critical role of network

Recent efforts attempting to in-situ track the polymer film formation during film blowing are summarized. The specially designed film blowing apparatus is firstly introduced, where the air ring is aligned along with the die, and it's capable of installation in the synchrotron beamline (SR-beamline). Later on, detailed structural evolution of different polymeric systems during film blowing, including polyethylene (PE) and poly(butylene adipate-co- butylene terephthalate) (PBAT), are obtained with the assistance of simultaneous acquired Small- and Wide Angle X-ray Scattering (SAXS/WAXS). The transient structure evolution information from oriented polymer melt to final crystalline tubular film clarifies the contribution of the crystallite-based network to final macroscopic performances. Also, the experimental results have shown the influence of intrinsic molecular characteristics and external processing parameters on the formation of stable tubular bubble. Additionally, the post-modification of the blown film, including stretching and surface treatment is also discussed. Current experimental efforts are expected to provide more detailed parameters for mathematical modeling of film blowing, which could help us modify or develop new numerical models.