Polyamide 11 porous films by NIPS: the influence of miscibility and polymer crystalline formation in pores structure and morphology

This study described the morphology, crystallinity, thermal and mechanical characterization of Polyamide 11 (PA11) porous film prepared by non-solvent induced phase separation (NIPS) method using formic acid (FA) as solvent. In addition, the miscibility of PA11/FA/H₂O system was performed to generate a ternary phase diagram. The porous films morphology was investigated by Scanning Electronic Microscopy (SEM) analysis, the crystallinity by X-Ray Diffractometer (XRD) and thermal study by Differential Scanning Calorimetry (DSC). A cellulosic reinforcement was used in porous films and the stress-strain analysis was performance by Dynamic Mechanical Analysis (DMA). The porous films were prepared with polymer composition of 15, 20 and 25 wt%. The porous films showed different microstructure in function of polymer concentration. The 20 and 25 wt% porous films showed micropores structures with medium pores diameters between 0-10µm calculated by image analysis. The XRD analysis show predominance of α crystalline form of polymer at 20 and 25 wt% porous films. The degree of crystallinity increases with polymer concentration increase. The stress-strain analysis of porous films shows a proportional dependence of Young’s modulus with the increase of polymer concentration in each film.

Keywords:
polymer; crystallinity; DSC; DMA; cellulose