SiOx/PET阻隔性复合薄膜结构变化与其阻隔性及增塑剂迁移的相互关系研究

SiOx used as the barrier layer of flexible packaging materials has excellent barrier property. It can prevent the food shelf-life from shortening because of the interaction between food and plastic, also can reduce the migration which plasticizer and other additives migrate to food so that to protect food safety. Consequently, it is vital important for food packaging materials security to understand inter-effects between structure of packaging materials and film barrier property and plasticizer migration. This study intends to deposite SiOx barrier layer on PET matrix to prepare SiOx/PET high barrier composite film by plasma enhanced chemical vapor deposition (the technology PECVD is environment protecting),and to study the composite film's properties. Then, to investigate structure and properties of PET layer under the influence of plasticizer via various analytical techniques such as X-ray photoelectron spectrometer(XPS),X-ray diffractometer (XRD),scanning electron microscope(SEM),atomic force microscope(AFM), Fourier transform infrared spectroscopy(FTIR),small angle/wide angle X-ray scattering and high performance liquid chromatography(HPLC). In addition, to reveal the mutual influence rule between structure of SiOx/PET and SiOx/PET film's barrier property and plasticizer migration, whilst to elucidate the rule that structural changes effect on barrier property and plasticizer migration for SiOx/PET high barrier composite film during its thermal processing. The research will provide basic data and theoretical reference for SiOx/PET composite films apply to food safely.

SiOx作为软包装材料的阻隔层具有优异的阻隔性能，可防止食品与塑料的相互作用而降低食品货架期，也可降低塑化剂等添加剂迁移到食品而危害到食品安全。弄清包装材料结构与薄膜的阻隔性及增塑剂迁移的相互影响对于食品包装材料的安全使用尤为重要。本项目拟采用无任何污染的等离子体化学气相沉积技术在PET基材上沉积SiOx阻隔层，采用X射线光电子能谱仪、X射线衍射仪、扫描电子显微镜、原子力显微镜、傅里叶变换红外光谱、小角/广角X射线散射及高效液相色谱等多种分析测试技术，研究增塑剂影响下PET膜材层的结构与性能，利用等离子体技术制备SiOx/PET高阻隔层复合薄膜并研究其性能。揭示SiOx/PET结构与其阻隔性及增塑剂迁移的相互影响规律，揭示热加工过程中SiOx/PET高阻隔性复合薄膜结构变化对材料阻隔性及增塑剂迁移的影响规律。研究将为SiOx/PET复合薄膜在食品上的安全使用提供基础数据和理论参考。

SiOx层具有优异的阻隔性能，可防止食品与材料相互作用而降低食品货架期的情况发生，也可阻碍增塑剂等添加剂向食品迁移而危害食品安全的行为。揭示包装材料结构与材料的阻隔性及增塑剂迁移的相互影响规律，对于食品接触材料的安全使用尤为重要。. 本项目采用无污染的低温等离子体增强化学气相沉积技术沉积SiOx阻隔层制备了SiOx/PET复合薄膜，并拓展制备了SiOx/PLA、SiOx/CNFs及SiOx/纸复合材料。通过电子万能材料试验机、SEM、AFM、FTIR、XRD、TGA、DSC、透湿透氧仪、接触角测量仪、固体紫外和HPLC等多种手段分析了复合材料的力学性能、表面形貌、化学组成、热稳定性、阻隔性、润湿性、透光率和抗迁移特性。得到了PECVD在柔性基底上沉积SiOx层的最佳工艺，及岛状-层状-岛层状模式的SiOx沉积机理；发现了SiOx层厚度增加未明显改变材料透光率，可显著提高材料的阻隔性（氧气透过率降低7.7%-79.3%，水蒸气透过率降低46.0%-77.3%）和润湿性（静态水接触角可提高约10-30°），但材料的力学性能则先增加后缓慢降低；发现了SiOx层还能降低DOP、DEDB、ATBC等增塑剂在食品模拟物中的迁移量（降低约11.43%-90%）、迁移速率，使迁移平衡点滞后；揭示了SiOx/PET复合薄膜结构变化与其阻隔性及增塑剂迁移的相互影响规律，以及对应的热加工过程中的影响规律，解释了SiOx层的抗迁移机理。. 该研究有利于促进我国高阻隔性塑料的理论的提高和推广应用；提出了阻隔性复合材料对减少食品成分与包装材料的相互作用从而延长食品的货架期，建立了相关的相容性理论，解释了其减少和降低污染物从塑料薄膜迁移到食品的机制，将为SiOx薄膜的抗迁移理论及解决食品包装安全问题奠定基础，为SiOx/PET复合薄膜在食品上的安全使用提供基础数据和理论参考。