Polymer Testing (Dec 2021)
The effect of the melt-drawing ratio on the microstructure and mechanical properties of poly(butylene succinate) cast films with row-nucleated lamellar structure
Abstract
High-performance PBS films can be prepared by the melt-stretching method. The effect of the melt-drawing ratio (MDR) on the mechanical properties and microstructure of PBS cast films prepared by melt-stretching is studied in this paper. The elastic modulus, tensile stress, and strain hardening increase with increasing MDR. With an MDR of 25–50, the crystalline morphology changes from deformed spherulites to row-nucleated lamellar structure. The lateral size and orientation of the lamellae apparently improve with the MDR. When the MDR is within 50–125, the row-nucleated lamellar structure improves slightly by increasing the lateral size and orientation of the lamellae. The component fraction and thickness of the mobile (MAF) and rigid (RAF) amorphous fractions and crystalline phase are nearly unchanged within the whole MDR range. The increases in lateral size and orientation improve the mechanical properties of the films. Significantly, the linear relationship between the elastic modulus and orientation at MDRs from 50 to 125 indicates that the elastic modulus is determined by the crystal orientation in PBS cast films with row-nucleated lamellae. This work evaluates the importance of orientation for microstructure and properties of PBS films, which may guide the processing of high-performance PBS films.
