SiOx/PET复合薄膜的力学性能及阻隔性能

目的基于氧化硅(SiO_x)镀层优异的性能,研究不同厚度的SiO_x层对SiO_x/PET复合薄膜力学性能和阻隔性能的影响,以期得到性能较优的SiO_x/PET复合薄膜。方法以自制的聚对苯二甲酸乙二醇酯(PET)薄膜为基材,采用等离子体增强化学气相沉积法沉积得到SiO_x层厚度分别为40,150,230,320 nm的SiO_x/PET复合薄膜,并进行傅里叶变换红外线光谱分析、力学性能和阻隔性能测试,以及薄膜表观形貌分析。结果沉积SiO_x层后,SiO_x/PET复合薄膜拉伸强度和断裂伸长率随SiO_x层厚度的增大先增大后减小,氧气透过率和水蒸气透过率则出现明显衰减而后逐渐平缓的趋势。SiO_x层厚度达150~230 nm时,复合薄膜的力学性能和阻隔性能表现较优,拉伸强度、断裂伸长率、氧气透过率以及水蒸气透过率分别提高了约25.0%,20.9%,79.3%,77.3%。结论适宜厚度的SiO_x层可以使得SiO_x/PET复合薄膜同时具备较优的力学性能和阻隔性能。

Mechanical Properties and Barrier Properties of SiOx/PET Composite Films

The work aims to obtain the SiOx/PET composite film with better performance by studying the effects of SiOx layer of different thicknesses on the mechanical properties and the barrier properties of SiOx/PET composite films, based on the excellent properties of silicon oxide (SiOx) layer. The SiOx layers with thickness of 40, 150, 230 and 320 nm were obtained by plasma enhanced chemical vapor deposition, with the self-made polythylene terephthalate (PET) film as the base material. Then, the Fourier transform infrared spectroscopy, and tests of mechanical properties and barrier properties were carried out, and the apparent morphology of the film was analyzed. After the SiOx layer was deposited, the tensile strength and elongation at break of the SiOx/PET composite films were increased first and then decreased with the increase in the thickness of SiOx layer, and the oxygen permeability and water vapor transmission rate were significantly attenuated and then gradually became gentle. The mechanical properties and barrier properties of the composite film were better when the thickness of SiOx layer was in the range of 150~230 nm. The tensile strength, elongation at break, oxygen permeability and water vapor transmission rate were improved by about 25.0%, 20.9%, 79.3% and 77.3%, respectively. The SiOx layer with suitable thickness can provide the SiOx/PET composite film with better mechanical properties and the barrier properties.