溶胶-凝胶法制备BOPP基阻隔性包装复合薄膜及其性能研究

发布时间：2018-04-16 08:08

本文选题：杂化复合膜 + 溶胶-凝胶　；参考：《浙江理工大学》2010年硕士论文

【摘要】： 聚烯烃类薄膜由于透明、易加工、价格低廉等优点而被广泛应用于食品、药品及电子元器件等商品的包装方面,但是,氧气、二氧化碳、水蒸气和有机小分子等物质易透过这些包装薄膜而影响被包装物的品质与寿命。因此,为了提高常用的双向拉伸聚丙烯(BOPP)薄膜的阻隔性能以满足阻隔性包装的需要,本文采用溶胶-凝胶法,以正硅酸乙酯(TEOS)为前驱体、添加硅烷偶联剂γ-缩水甘油醚氧丙基三甲氧基硅烷(KH560)以提高涂层与基体的附着牢度、无水乙醇为共溶剂、盐酸为催化剂,在BOPP薄膜上负载SiO_2层。再以聚乙烯醇(PVA)和壳聚糖(CS)为有机物,制备PVA/SiO_2有机-无机杂化层和CS/SiO_2有机-无机杂化层。最终,制备了三种BOPP基阻隔性包装复合薄膜,并表征和测试其结构与性能。主要结论如下: 在SiO_2/BOPP阻隔性复合薄膜中,通过正交试验和单因素试验,分别讨论了KH560/TEOS摩尔比、无水乙醇量、去离子水量和盐酸量四个因素对复合薄膜阻隔性能的影响。确定制备SiO_2阻隔性复合薄膜原料的最佳摩尔配比为:(TEOS+KH560):乙醇:去离子水:盐酸=1:4:3:1.2,KH560:TEOS =2:3。此时,SiO_2复合薄膜的氧气阻隔性能是纯BOPP薄膜的21倍;水蒸气阻隔性能是纯BOPP薄膜的1.7倍;拉伸强度、断裂伸长率和透光率均优于纯BOPP薄膜。在PVA/SiO_2/BOPP杂化阻隔性复合薄膜中,随PVA含量的增加,杂化复合薄膜的氧气阻隔性能提高,但水蒸气阻隔性能降低。当PVA质量分数为80%时,杂化复合薄膜的氧气阻隔性能是纯BOPP薄膜的308倍;但水蒸气阻隔性能是纯BOPP薄膜的一半;拉伸强度和断裂伸长率分别是纯BOPP薄膜的1.4倍和1.7倍;透光率大于90%,具有良好的透明性。在CS/SiO_2/BOPP杂化阻隔性复合薄膜中,杂化层与BOPP薄膜紧密附着,表面无分相或开裂现象。随CS含量的增加,杂化复合薄膜的氧气阻隔性能先提高后降低;水蒸气阻隔性能持续降低。当CS质量分数为18%时,杂化复合薄膜的氧气阻隔性能是纯BOPP薄膜的112倍;水蒸气阻隔性能是BOPP薄膜的1.3倍;拉伸强度和断裂伸长率分别是纯BOPP薄膜的1.5倍和1.8倍;透光率低于纯BOPP薄膜,但仍具有良好的透明性。
[Abstract]:Polyolefin films are widely used in packaging of food, medicine and electronic components due to their advantages of transparency, easy processing and low price. However, oxygen, carbon dioxide, carbon dioxide, etc.Substances such as water vapor and small organic molecules can easily affect the quality and life of the packaged materials through these packaging films.Therefore, in order to improve the barrier properties of the commonly used biaxially stretched polypropylene (BOPP) films to meet the needs of barrier packaging, a sol-gel method with tetraethyl orthosilicate (TEOS) as the precursor was used in this paper.Silane coupling agent 纬 -glycidyl ether oxy propyl trimethoxysilane (KH 560) was added to improve the adhesion fastness of the coating to the substrate. Anhydrous ethanol was used as the co-solvent and hydrochloric acid as the catalyst to support the SiO_2 layer on the BOPP film.PVA/SiO_2 organic-inorganic hybrid layer and CS/SiO_2 organic-inorganic hybrid layer were prepared by using polyvinyl alcohol (PVA) and chitosan (CS) as organic compounds.Finally, three kinds of BOPP based barrier packaging composite films were prepared, and their structures and properties were characterized and tested.The main conclusions are as follows:The effects of KH560/TEOS molar ratio, anhydrous ethanol, deionized water and hydrochloric acid on the barrier properties of SiO_2/BOPP films were discussed by orthogonal test and single factor test.The optimum molar ratio of SiO_2 barrier composite film was determined to be: 1: 1: 4: 1: 1: 1: 1: 1: 1: 1: 1: 1: 1: 1: 1: 1: 1: 3.The oxygen barrier property of SiO2 composite film is 21 times of that of pure BOPP film, the water vapor barrier property is 1.7 times that of pure BOPP film, and the tensile strength, elongation at break and transmittance of pure BOPP film are better than that of pure BOPP film.In PVA/SiO_2/BOPP hybrid barrier composite film, the oxygen barrier property of hybrid composite film increases with the increase of PVA content, but the water vapor barrier property decreases.When the mass fraction of PVA is 80, the oxygen barrier property of hybrid composite film is 308 times that of pure BOPP film, but the water vapor barrier property is half of that of pure BOPP film, the tensile strength and elongation at break are 1.4 times and 1.7 times of that of pure BOPP film, respectively.The transmittance is greater than 90 and has good transparency.In CS/SiO_2/BOPP hybrid barrier composite film, the hybrid layer is tightly attached to BOPP film, and there is no phase separation or cracking on the surface.With the increase of CS content, the oxygen barrier property of hybrid composite films first increases and then decreases, while the water vapor barrier performance decreases continuously.When CS mass fraction is 18, the oxygen barrier property of hybrid composite film is 112 times that of pure BOPP film, the water vapor barrier property is 1.3 times of that of BOPP film, the tensile strength and elongation at break are 1.5 times and 1.8 times of that of pure BOPP film, respectively.The transmittance of BOPP film is lower than that of pure BOPP film, but it still has good transparency.
【学位授予单位】：浙江理工大学
【学位级别】：硕士
【学位授予年份】：2010
【分类号】：TB383.2;TB484

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