【作者】 施春荧；

【导师】 何映平； 韩永生；

【作者基本信息】 华南热带农业大学 ， 农产品加工及贮藏工程， 2006， 硕士

【摘要】 果蔬保鲜膜是人们日常生产生活中需求越来越大的一种功能性塑料。本论文实验室制备纳米TiO₂,将纳米粒子通过不同的方法添加到聚氯乙烯,聚丙烯,聚乙烯等聚合物中混合挤出吹膜,并对各种纳米薄膜的力学性能,透气性能,抗菌性能作了一系列的研究。根据最佳配方制备适合毛叶枣贮藏保鲜的塑料薄膜,并对毛叶枣的保鲜效果作了各项生理指标的测试研究。首先,通过纳米TiO₂粒子改性塑料薄膜,研究了纳米TiO₂在各种聚合物薄膜中的分散以及纳米粒子的添加量对塑料薄膜的力学性能和透气性能的影响。结果表明:纳米粒子在聚合物中均能达到纳米级分散;随着纳米TiO₂的添加量的增加,各种薄膜的力学性能均出现先升高后下降的趋势;各种薄膜的气体透过率均有不同程度的减小,减小较为明显的是透氧率。其次,对各种纳米薄膜的抗菌性能作了研究,并研究了纳米TiO₂的添加量对聚乙烯薄膜抗菌性能的影响。结果表明,添加纳米TiO₂的薄膜均存在一定的抑菌作用;添加2份的纳米TiO₂的PVC,PP,LDPE薄膜的抗菌率分别为41.67%,21.43%,31.43%。最后,对于不同贮藏条件以及不同透气量的自制纳米保鲜膜对毛叶枣的保鲜性能指标作试验分析,实验结果表明,薄膜包装的保鲜效果明显优于其他包装,实验进一步发现透O₂量在6491.23cm³/m²·d·bar,透CO₂量在24346.84 cm³/m²·d·bar的纳米TiO₂/LDPE薄膜包装条件下,毛叶枣的保鲜时间最长,常温可保鲜18天,冷藏条件下更是延长到58天。更多还原

【Abstract】 In this paper, the performance of mechanics, gas permeation and anti-bacterial of different nano-polymers’film is studied. And the quality of ber planted in torrid zone packed with films and stored at different temperature was investigated.Firstly, nano- TiO₂ was prepared and used to modify thin films, the effects of the adding amounts of filler on the permeation and mechanical property of films were studied. The results showed that nano- TiO₂ could be dispersed into films equably; the amounts of nano- TiO₂ increased, the mechanical property appeared increasing first and then decreasing; but the gas permeation rate decreased gradually.Secondly, the anti-bacterial of nano- TiO₂/polymer films and the influence of nano-TiO₂ dose to anti-bacterial of LDPE film were studied. The results indicated that when the adding amount is 2, the films have anti-bacterial activity, and the anti-bacterial rate were 41.67% of PVC film,21.43%of PP film and 31.43% of LDPE film.At last, nano-TiO₂/LDPE films with different gas permeation were used to pack ber , which stored at normal and refrigerate temperature. The preserving performance was analyzed. The result showed that the preserving effects of polymer film packaging is better than others, and when the nano-TiO₂/LDPE films with O₂ permeation to 6491.23cm³/m²·d·bar, and CO₂ permeation to 24346.84 cm³/m²·d·bar, ber can be preserved more than 18 days at normal temperature and 58days at cold storage.更多还原