磺化聚醚醚酮/聚乙烯复合膜的制备及对生菜的贮藏保鲜

Preparation of SPEEK/PE Composite Membrane and Application in Lettuce Preservation

摘要:

以磺化聚醚醚酮（SPEEK）为涂层，聚乙烯（PE）为基底，制备了自发式气体调节SPEEK/PE复合膜，研究不同磺化度SPEEK对SPEEK/PE复合膜的透气性、透湿性、防雾性能等气调特性的影响，并将SPEEK/PE复合膜应用于生菜的气调气调保藏。结果表明，与SPEEK膜相比，不同磺化度SPEEK/PE气调复合膜对CO2和O2的透气系数均有轻微下降，SPEEK/PE复合膜对CO2/O2的分离系数从0.73增加到5.58。不同磺化度的SPEEK/PE复合膜对水蒸气的透过系数在1.50×10-14~4.00×10-14 g·cm/(cm·s·Pa)之间，与SPEEK膜2.00×10-12~2.46×10-12 g·cm/(cm·s·Pa)相比，水蒸气透过系数下降两个数量级，且SPEEK/PE复合膜具有良好的防雾性能。高磺化度SPEEK/PE复合膜对生菜具有良好的气调保藏效果，与空白对照和PE膜组相比，保藏20 d后生菜失重率分别降低92.25%、22.06%，叶绿素损失分别减少85.00%、50.00%，总酚含量下降分别减少73.97%、26.98%，维生素C含量损失分别降低50.00%、31.48%，可溶性固形物含量下降分别减少67.21%、21.31%。4 ℃时SPEEK/PE复合膜能将生菜保藏环境中的CO2和O2含量分别维持在10.00%~12.00%和4.00%~5.00%，并将生菜保藏期期延长到20 d。

Abstract:

Spontaneous gas-regulated sulfonated polyetheretherketone (SPEEK)/polyethylene (PE) composite membranes were prepared. The effect of SPEEK with different sulfonation degree on gas permeability, moisture permeability and anti-fog properties of SPEEK/PE composite membranes were studied by a series of testing methods. Then, the SPEEK/PE composite membranes ware applied to preserve lettuce. The results showed that the permeability coefficient of different sulfonation degree of SPEEK/PE modified membranes for CO2 and O2 decreased slightly. The separation coefficient of SPEEK/PE composite membrane for CO2/O2 increased from 0.73 to 5.58. The moisture permeability of composite membrane was between 1.50×10-14 ~4.00×10-14 g·cm/(cm·s·Pa), which reduced by two orders of magnitude, compared to SPEEK membrane(between 2.00×10-12~2.46×10-12 g·cm/(cm·s·Pa). And the SPEEK/PE composite membran had good properties of anti-fog. The results of preservation experiment indicated that high sulfonation degree of SPEEK/PE composite membrane had good air-conditioning preservation effect on lettuce. Compared to ordinary PE group and blank group, the changes of the weight loss rate, chlorophyll content, total phenolic content, vitamin C content and soluble solid content of lettuce were reduced during the preservation process, and the preservation periods of composite membrane groups were extended by 12 days and 4 days respectively. Based on the preservation effect, at 4 ℃, SPEEK/PE composite film could maintain the content of CO2 and O2 in the packaging environment at 10.00%~12.00% and 4.00%~5.00% respectively, and extend the storage period of lettuce to 20 days.