尼龙66/紫外辐照线性低密度聚乙烯共混物的力学性能

Studies on LLDPE functionalized by ultraviolet irradiation and mechanical properties of PA66/irradiated LLDPE blends

The effect of UV irradiation on the structure and properties of linear low-density polyethylene (LLDPE) and the mechanical properties of nylon 66 (PA66)/LLDPE blends were studied with FTIR and XPS, measurements of gel, melt index, and water contact angle, and mechanical property tests. The results show that oxygen-containing groups such as C-O, C=O and C (=O) O were introduced onto molecular chains of LLDPE by the UV irradiation in air without adding any additives. The content of these groups increased with irradiation time. Gel formation was found in LLDPE after 12 h UV irradiation, and the gel fraction increased with the irradiation time. Melt index and water contact angle of the irradiated LLDPE decreased. Due to the introduction of the oxygen-containing groups, interfacial interactions between PA66 and the irradiated LLDPE increased. Therefore mechanical properties of PA66/irradiated LLDPE blends were improved compared with PA66/LLDPE blend. Tensile strength and notch impact strength of the PA66/irradiated LLDPE blends increased with irradiation time.