Structure and Properties of PA66/Irradiated LLDPE Blends

The oxygen-containing groups such as C—O, C=O, and C(=O)O were introduced onto linear low density polyethylene (LLDPE) chains by ultraviolet irradiation in air. The irradiated LLDPE was used for modifying polyamide 66 (PA66), and PA66/irradiated LLDPE (90/10) blends were prepared. The structure and properties of the PA66/irradiated LLDPE (90/10) blends were investigated by X-ray diffraction, differential scanning calorimetry, scanning electron microscopy, thermogravimetry, the Molau test, and mechanical measurements. Compared with that in PA66/LLDPE (90/10) blends, the irradiated LLDPE in PA66/irradiated LLDPE (90/10) blends remained in an orthorhombic structure, and the face space did not change. But the melting temperature and the crystallinity of irradiated LLDPE and PA66 in PA66/irradiated LLDPE (90/10) blends decreased due to the strong interface interaction between irradiated LLDPE- and PA66-restrained crystallization. The dispersion of irradiated LLDPE and interfacial adhesion between irradiated LLDPE and PA66 in PA66/irradiated LLDPE (90/10) blends were improved. With increasing irradiation time, the tensile and the impact strength of PA66/irradiated LLDPE (90/10) blends first increased and reached a maximum when the irradiation time was 36 h. Compared with that of PA66/LLDPE (90/10) blends, the tensile and the impact strength of PA66/LLDPE irradiated for 36 h (90/10) blends was enhanced by 31% and 160%, respectively.