羟丙基甲基纤维素水溶性包装薄膜的制备及性能研究

发布时间：2018-04-24 20:21

本文选题：水溶性包装薄膜 + 羟丙基甲基纤维素　；参考：《浙江理工大学》2017年硕士论文

【摘要】：水溶性包装薄膜是一种新型的绿色环保包装材料,在欧美等国家已受到广泛关注,不仅使用安全方便,还可解决包装废弃物的处理问题。目前,水溶性薄膜主要以聚乙烯醇、聚氧化乙烯等石油基材料为原料,石油属于不可再生资源,大量使用会造成资源短缺。也有以淀粉和蛋白质等天然物质作为原料的水溶性薄膜,但这些水溶性薄膜的力学性能较差。羟丙基甲基纤维素(HPMC)是天然高分子材料,资源丰富、可再生,而且有良好的水溶性和成膜性,是制备水溶性包装薄膜的理想原料。本文以羟丙基甲基纤维素为原料,采用溶液流延成膜法制备一种新型的水溶性包装薄膜。讨论了HPMC成膜液浓度、成膜温度变化对HPMC水溶性包装薄膜的拉伸强度、断裂伸长率、透光率、水溶性等性能的影响,并采用丙三醇、山梨醇和戊二醛进一步提高HPMC水溶性包装薄膜的性能。最后,为了扩大HPMC水溶性包装薄膜在食品包装上的应用,采用竹叶抗氧化剂(AOB)提高HPMC水溶性包装薄膜的抗氧化性能。主要研究结果如下:(1)随着HPMC浓度的增加,HPMC薄膜拉伸强度、断裂伸长率提高,透光率下降。当HPMC浓度为5%、成膜温度为50°C时HPMC薄膜的综合性能较好,此时拉伸强度为116MPa左右,断裂伸长率为31%左右,透光率90%,水溶时间55min。(2)增塑剂丙三醇和山梨醇改善了HPMC薄膜的力学性能,使其断裂伸长率显著增加。当丙三醇添加量在0.05%~0.25%之间时效果最好,HPMC水溶性包装薄膜的断裂伸长率达到50%左右;山梨醇添加量为0.15%时,其断裂伸长率增加到45%左右。HPMC水溶性包装薄膜经丙三醇和山梨醇改性后,拉伸强度降低、光学性能下降,但下降幅度不大。(3)戊二醛交联HPMC水溶性包装薄膜的红外光谱(FTIR)显示戊二醛与薄膜发生了交联反应,降低了HPMC水溶性包装薄膜的水溶性。0.25%时戊二醛添加量时,薄膜的力学性能和光学性能达到最优,当戊二醛添加量为0.44%时,水溶时间达到135min。(4)在HPMC水溶性包装薄膜成膜液中添加适量的AOB可以提高薄膜的抗氧化性能。在0.03%AOB添加量时,AOB/HPMC薄膜对DPPH自由基的清除率达到89%左右,清除效率最好,比未加入AOB时的HPMC薄膜提高了61%,水溶性能也显著提高。
[Abstract]:Water-soluble packaging film is a new kind of green packaging material, which has been widely concerned in Europe and America. It is not only safe and convenient to use, but also can solve the problem of packaging waste disposal. At present, the water-soluble film is mainly based on polyvinyl alcohol, polyvinyl oxide and other petroleum-based materials, oil is a non-renewable resource, a large number of use will lead to a shortage of resources. There are also water-soluble films with natural materials such as starch and protein, but the mechanical properties of these water-soluble films are poor. Hydroxypropyl methyl cellulose (HPMC) is a natural polymer material, rich in resources, renewable, water-soluble and film-forming, and is an ideal raw material for the preparation of water-soluble packaging film. In this paper, a novel water-soluble packaging film was prepared from hydroxypropyl methyl cellulose by solution casting method. The effects of the concentration of HPMC film-forming solution and the change of film forming temperature on the tensile strength, elongation at break, transmittance and water solubility of HPMC water-soluble packaging film were discussed. Sorbitol and glutaraldehyde further improved the properties of HPMC water-soluble packaging film. Finally, in order to expand the application of HPMC water-soluble packaging film in food packaging, the antioxidant from bamboo leaves was used to improve the antioxidant properties of HPMC water-soluble packaging film. The main results are as follows: (1) with the increase of HPMC concentration, the tensile strength of HPMC films increases, the elongation at break increases and the transmittance decreases. When the concentration of HPMC is 5 and the film forming temperature is 50 掳C, the comprehensive properties of HPMC film are better. The tensile strength is about 116MPa, the elongation at break is about 31%, the transmittance is 90%, and the water solution time is 55 min. 2) the plasticizer glycerol and sorbitol have improved the mechanical properties of HPMC film. The elongation at break increased significantly. When the dosage of glycerol was between 0.05% and 0.25%, the best result was that the elongation at break of HPMC water-soluble packaging film was about 50%, and that of sorbitol was 0.15%. The elongation at break increased to about 45%. After modified by glycerol and sorbitol, the tensile strength and optical properties of the film were decreased. However, the IR spectra of glutaraldehyde crosslinked HPMC water-soluble packaging film showed that glutaraldehyde reacted with the film, which decreased the water-solubility of HPMC water-soluble packaging film. The mechanical and optical properties of the films were optimized. When the glutaraldehyde content was 0.44 and the water solubilization time was 135min. 4) adding a proper amount of AOB in the film forming solution of HPMC water-soluble packaging film could improve the oxidation resistance of the film. When the amount of 0.03%AOB was added, the scavenging rate of DPPH radical was about 89%, and the scavenging efficiency was the best. Compared with the HPMC film without AOB, the scavenging efficiency of AOB / HPMC film was 61% higher than that of HPMC film without AOB, and the water-solubility energy was also significantly increased.
【学位授予单位】：浙江理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB484;TB383.2

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