纳米SiO_2对聚乳酸薄膜阻隔性的影响

Effect of Nano-silicon Dioxide on the Barrier Properties of Poly(L-lactic acid)

采用熔融共混法,向聚左旋乳酸(PLLA)分别加入亲水性和疏水性SiO_2对其进行改性。采用差示扫描量热分析仪(DSC)、透氧仪和透湿仪对PLLA/SiO_2薄膜的热学性能和阻隔性能进行了研究。结果表明,亲水SiO_2或疏水SiO_2的加入,使PLLA薄膜的结晶度有所提高,同时阻氧性有所降低,说明虽然SiO_2分散相使PLLA薄膜的结晶度提高,但团聚状态的SiO_2使PLLA薄膜缺陷增多,当后者占优时薄膜阻隔性就会降低。此外,只有加入较高含量的疏水性SiO_2时才能使PLLA薄膜的阻湿性能有所提高。

To improve the gas barrier property of poly （L-lactic acid） （PLLA）, hydrophilic and hydrophobic nano-silieon dioxide （SiO2 ） were added into PLLA by melt-blending process. The thermal and barrier properties of the PLLA/SiO2 film were evaluated by differential scanning calorimetry （ DSC ） , oxygen permeation analyzer and water vapor permeation analyzer. The results show that by the addition of SiO2 , the crystallinity of PLLA is improved and the oxygen barrier performance of PLLA is weaken. It indicates that although the dispersion phase of SiO2 improves the crystallinity of PLLA, the aggregation state of SiO2 increases the defects of PLLA film. When the latter becomes dominant, the barrier properties of PLLA film decrease. In addition, the water vapor barrier property of PLLA can be improved only when the higher concentration of hydrophobic SiO2 is added into the PLLA.