With the guidance of Prof. Li and Post doctor Ji the the Structural Evolution of LLDPE Bubble during film blowing is studied by master Haoyuan Zhao et al. The related work has been published in Journal of Polymer Science Part B-Polymer Physics.
The structural evolution during the linear low-density polyethylene (LLDPE) film blowing has been studied with a combination of home-made blown film apparatus and in situ WAXS and SAXS measurements. Analyzing the evolution of orientation parameters and crystallinity of the bubble shows that the blown film process can be divided into four regions. Distinctly different features of LLDPE bubble are observed in first three regions: (a) lower orientation parameters during the blown film process, (b) higher crystallinity is required to form a deformablecrystalline crosslinked network, and (c) the weaker stretching effect and the difficulty of reaching equilibrium when the crystal network deforms. These results should provide a basis for understanding the poor blown film stability of LLDPE.
This work is supported by the National Key Research and Development Program of China (2016YFB0302500) and the National Natural Science Foundation of China (51703217 and 51633009). The experiments are carried out in Shanghai Synchrotron Radiation Facility (SSRF).
Related links: https://onlinelibrary.wiley.com/doi/full/10.1002/polb.24727
