基于共轭二烯聚合物环化物的吸氧薄膜的制备与性能研究

发布时间：2018-06-01 11:34

  本文选题：环化SBS + α-蒎烯树脂　； 参考：《江南大学》2015年硕士论文

【摘要】：氧气是引起食品腐坏变质的重要因素之一,它能够引起食品氧化、细菌繁殖从而导致食品变味、变色以及营养物质流失,因此食品包装内氧气的含量必须低于其允许值。降低食品包装内氧气含量的传统方法有气调包装和真空包装,但是这两种方法均不能完全除去包装内的氧气,包装内部仍然会有微量的氧气残留。吸氧包装克服了这两种包装方法除氧不彻底的缺点,能够主动清除包装内部的氧气。吸氧包装材料研究的核心内容是活性吸氧物质的研究。本课题以苯乙烯-丁二烯共聚物(SBS)为原料,经环化反应制备环化SBS,与引发剂、过渡金属催化剂共混制备吸氧环化SBS共混物。将吸氧环化SBS共混物与α-蒎烯树脂共混制备吸氧环化SBS-α-蒎烯树脂共混物。利用制备的两种吸氧共混物与基材共混物制备吸氧单层膜。主要研究内容和研究成果如下:(1)采用正交试验设计,以吸氧性能为考察指标,对影响环化SBS吸氧共混物吸氧性能的关键因素进行优化,确定制备环化SBS吸氧共混物的优化工艺条件:SBS的浓度20%,对甲苯磺酸的用量2%,反应温度75℃,反应时间3h,在该条件下的制备的环化SBS吸氧共混物的吸氧能力达40.5 m L/g,吸氧速率为0.129 m L?g-1?cm-2?d-1。研究贮藏条件对环化SBS吸氧共混物吸氧性能的影响,结果表明,随着贮存时间的延长以及贮存温度的升高,吸氧共混物的吸氧性能有所降低,而贮存湿度对于吸氧共混物的吸氧性能影响不显著。(2)考察α-蒎烯树脂的添加量对环化SBS-α-蒎烯吸氧树脂共混物吸氧性能的影响,结果表明,当α-蒎烯树脂的添加量为15%时,吸氧树脂共混物在23℃、4℃条件下达到的最大吸氧量分别为36.2 m L/g、35.6 m L/g。另外,在贮存过程中,环化SBS-α-蒎烯吸氧树脂共混物的吸氧性能有一定程度的降低,但其吸氧性能降低的幅度会随着贮存时间延长或贮存温度的继续升高而减弱。(3)制备分别以环化SBS吸氧共混物及环化SBS-α-蒎烯吸氧共混物为活性吸氧物质的吸氧LDPE膜,考察吸氧共混物的添加量对吸氧LDPE膜吸氧性能、阻隔性能、物理力学性能等的影响。结果表明,所制备的吸氧LDPE达到了预期的吸氧性能,且吸氧效果不会随着贮存时间的延长而发生明显变化;另外,添加吸氧物质后,LDPE仍具有热封性能,且与纯LDPE膜相比,吸氧LDPE膜的热封强度变化不显著;但是吸氧共混物的添加会在一定程度上削弱吸氧薄膜的力学性能和阻隔性能。
[Abstract]:Oxygen is one of the important factors that cause food decay and deterioration. It can cause food oxidation, bacterial reproduction, resulting in food flavor, color change and loss of nutrients. Therefore, the content of oxygen in food packaging must be lower than its allowable value. The traditional methods to reduce the oxygen content in food packaging are atmosphere controlled packaging and vacuum packaging. However, these two methods can not completely remove the oxygen in the packaging, and there will still be trace oxygen residues in the packaging. Oxygen-absorbing packaging overcomes the shortcoming of incomplete deoxygenation and can remove the oxygen inside the package on its own initiative. The core of the research on oxygen absorbing packaging materials is the study of active oxygen absorbing materials. In this paper, styrene butadiene copolymers (SBSs) were used as raw materials to prepare cyclized SBSs by cyclization and blending with initiators and transition metal catalysts to prepare oxygen adsorbent cyclized SBS blends. SBS- 伪 -pinene resin blend was prepared by blending the oxygen-absorbing cyclized SBS blends with 伪 -pinene resin. Oxygen absorbing monolayer films were prepared from two kinds of oxygen absorbing blends and substrates. The main research contents and results are as follows: (1) the key factors affecting the oxygen absorption of cyclized SBS blends were optimized by using the orthogonal test design and the oxygen absorption performance as an index. The optimum process conditions for the preparation of cyclized SBS blends were determined. The concentration of 20% SBS and the dosage of p-toluenesulfonic acid were determined. The reaction temperature was 75 鈩，

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