改性水滑石/聚乙烯醇复合膜的制备及性能

采用焙烧复原法将山梨酸(SA)插入水滑石(LDH)层间合成了纳米插层材料SA-LDH,将其与聚乙烯醇(PVA)共混,通过溶液流延法制备得到复合薄膜SA-LDH/PVA。采用傅里叶变换红外光谱(FT-IR)、X-射线衍射(XRD)、热重-差热分析(TG-DSC)和扫描电镜(SEM)对其结构、热稳定性以及形貌进行表征,并测试了复合薄膜的力学性能、溶胀率、溶解率和抑菌性能。结果表明:复合薄膜SA-LDH/PVA中SA-LDH含量为5 wt%时得到的LDH晶型最为完整,对应的SA-LDH片层在PVA薄膜中分散比较均匀;添加3 wt%SA-LDH可提高PVA膜的热稳定性;SA-LDH添加量为5 wt%和7 wt%时,提高了复合膜的抗拉性能和断裂伸长率;SA-LDH的添加提高了PVA膜的耐水性能;SA-LDH的添加量分别为5 wt%和6 wt%时,SA-LDH/PVA复合薄膜对金黄色葡萄球菌和大肠杆菌的抑菌效果最佳。制备的改性水滑石/聚乙烯醇复合抑菌膜,为食品包装领域提供一种广谱的抑菌材料。

Preparation and Properties of Modified Hydrotalcite/Polyvinyl Alcohol Composite Membrane

The nanointercalated material SA-LDH was synthesized by inserting sorbic acid(SA)into the layers of hydrotalcite(LDH)by calcination-regeneration method,then it was blended with polyvinyl alcohol(PVA)and the composite membrane SA-LDH/PVA was prepared by the solution casting method.The structure,thermal stability and morphology were characterized with Fourier transform infrared spectroscopy(FT-IR),X-ray diffraction(XRD),thermogravimetric-differential thermal analysis(TG-DSC)and scanning electron microscope(SEM).And the mechanical properties,swelling rate,dissolution rate and antibacterial properties of the composite membrane were tested.The results showed that the LDH crystal form obtained with SA-LDH content of 5 wt%was the most complete;the SA-LDH layers were uniformly dispersed in the PVA membrane;3 wt%addition of SA-LDH could improve the thermal stability of PVA membrane;the tensile propertiesand elongation at break of the composite membrane were improved when the addition of SA-LDH was 5 wt%and 7 wt%;the addition of SA-LDH improved the water resistance of the PVA membrane;the SA-LDH/PVA composite membrane had the best antibacterial effect on Staphylococcus aureus and Escherichia coli when the addition amount of SA-LDH was 5 wt%and 6 wt%respectively.The hydrotalcite/polyvinyl alcohol composite antibacterial membrane provides an inclusive antibacterial material for the food packaging field.