The Effect of Stretching on the Crystal Structure and Crystal Orientation of PA510/SiO2 Films.

In order to explore the relationship between the microstructure and macroscopic properties of PA510/SiO2 films, the effect of the stretching on the crystal structure and crystal orientation of stretched PA510/SiO2 films was studied. It could be seen from the transmission electron microscopy (TEM) graphs that the layered SiO2 molecules were mainly oriented toward the machine direction (MD) and the dispersion could be improved by stretching. Through wide-angle X-ray scattering (WAXS) analysis, PA510/SiO2 stretched films only contained a γ crystal form. During uniaxial stretching, especially for 1 × 3 film, the γ1(100) crystal form was obviously oriented in the equatorial direction, and the orientation of γ2(004) and γ3(006) crystal forms could be observed in the meridian direction. According to the Herman orientation function, the orientation of the b-axis in the MD increased with the increase of the stretching ratio. It was worth noting that the orientation of the crystal region was more obvious. The addition of SiO2 and the orientation of the crystalline and amorphous regions could improve the barrier properties of the films. The changes in the optical properties of stretched films were affected by the dispersion state of SiO2 and the surface roughness.