目的 提高聚乳酸（PLLA）的韧性、 强度及阻氧性能。方法 采用双螺杆挤出流延线制备单轴拉伸 PLLA/聚丁二酸丁二醇酯（PLLA/PBS）共混薄膜， 用万能拉伸试验机、 差示扫描量热分析仪（DSC）和透氧仪， 对不同拉伸比例的 PLLA/PBS 共混薄膜的力学性能、 热学性能和阻氧性进行了评估。结果 随着拉伸比例的增大， PLLA/PBS共混薄膜屈服强度和弹性模量增大， 断裂伸长率呈先增大后降低的趋势。随拉伸比例的增大， PLLA/PBS共混薄膜结晶速率明显提高， 其阻氧性也得到一定的改善。结论 通过单轴拉伸和与PBS共混提高了PLLA的韧性和强度， 中等拉伸比例的PLLA/PBS共混薄膜的阻氧性相对较好。

Objective To improve the toughness, strength and oxygen barrier properties of poly(L-lactic acid)(PLLA). Methods Uniaxially stretched PLLA/poly(butylene succinate) (PLLA/PBS) blend film was prepared through twin-screw extrusion line. Universal tensile testing machine, differential scanning calorimetric analyzer and oxygen permeability test were used to evaluate the mechanical, thermal and oxygen barrier behavior of PLLA/PBS film with different draw ratios. Results Yield strength and Young′ s modulus of uniaxially stretched PLLA/PBS film were increased. But the elongations at break first increased and then decreased with the increase of the draw ratios. Crystallization rate of PLLA/PBS film increased with the increase of the draw ratios and its oxygen barrier properties were also improved. Conclusion By uniaxial stretching and blending with PBS, the toughness and strength of PLLA were improved, furthermore, the oxygen barrier properties of the medium stretched PLLA/PBS film were relatively good.