Polyolefin microporous separators, polyvinyl alcohol (PVA) polarizing films, polyethylene terephthalate (PET) optical protective films, and polymethyl methacrylate (PMMA) compensation films all require post-stretching processes during actual manufacturing. These processes serve to generate microporous structures, form oriented iodine complexes, and enhance anisotropy and overall mechanical performance. They involve several fundamental scientific issues, including the deformation mechanisms of semicrystalline polymers during stretching, the complexation mechanisms under the coupling of stretching and chemical reactions, as well as the stretch-induced crystallization and fracture behaviors of amorphous materials.
To address these fundamental scientific problems, the Engineering Laboratory has conducted a series of studies by integrating time-resolved synchrotron radiation techniques with simulation methods such as finite element analysis.
1. Deformation and Phase Transition in the Post-Stretching Process of Semicrystalline Polymers
Structural Evolution Phase Diagram of Highly Oriented Lamellar Clusters in the Strain–Temperature Two-Dimensional Space
2. Deformation and Phase Transition in the Post-Stretching Process of Amorphous Polymers
(a) Tensile mechanical curves of PET samples with different moisture contents; (b) Division of typical regions during the stretching process;
(c) Crystallinity of PET samples with different moisture contents; (d) Dependence of crystallinity on external work.
