聚碳酸亚丙酯的改性及其在包装领域中的应用性能研究

发布时间：2018-04-29 10:19

  本文选题：聚碳酸亚丙酯 + 纳米纤维素　； 参考：《大连工业大学》2016年硕士论文

【摘要】：随着人们生活水平的提高,塑料包装作为包装产业的主力军,已经在日用品、食品等领域发挥着不可替代的作用。但由于塑料存在回收困难、难以降解等问题,导致其引起的环境污染越来越严重。解决这个问题的一种有效途径在于研究出安全无毒并且可生物降解的新型“绿色”包装材料。聚碳酸亚丙酯(PPC)是由“温室气体”二氧化碳和环氧丙烷为原料合成的一种完全可降解的环保塑料,是目前最有希望的环保塑料之一。这种材料不仅是充分利用“温室气体”二氧化碳,转化成对环境友好的可降解塑料,而且能够避免传统塑料产生的对环境的二次污染问题。此外还拓展了塑料的应用,在一定程度上缓解了石油资源的消耗。纳米纤维素(NCC)是一种原料来源广泛、成本低、在功能材料领域有着广阔前景的新型功能材料。本论文通过硫酸水解法将微晶纤维素(MCC)制备NCC,并将其作为PPC的改性剂,制备出一种适用于包装领域的环境友好型PPC/NCC纳米复合材料,为其作为新型塑料包装材料的大规模生产和应用奠定了基础。实验中确定了制备NCC的最佳条件为:硫酸浓度为65wt%,水解温度为45℃,水解时间为1.5h。在此条件下制备的NCC为纤维素Ⅰ型,聚合度为114,结晶度为72.4,透视显微镜(TEM)显示其长度范围在200~380nm,宽度范围在20~40nm,具有较大的长径比;红外光谱分析(FTIR)显示NCC仍具有纤维素的基本化学结构。采用熔融共混法进行了PPC/NCC纳米复合材料的制备和工艺条件的研究。实验结果表明,当控制熔融温度在135℃,熔融时间为15min,添加1wt%的封端剂MA时,获得的复合材料性能优异。FTIR显示PCC与NCC之间并未发生化学反应,两者仍具备原有的化学性质。扫描电镜(SEM)结果显示随着NCC含量增多,纳米复合材料的相形态由“海-岛”结构变为纤维状聚集结构。最后,考察了PPC/NCC纳米复合材料的包装应用性能。力学性能上,纳米复合材料发生断裂时由韧性断裂变为脆性断裂,当NCC含量为1.5%时,复合材料的拉伸强度相比PPC提升了288%,而断裂伸长率仅为原来的1.6%;冲击强度相比PPC提高了近4倍。耐热性能上,纳米复合材料表现的更好,当NCC的含量在2.5%时,纳米复合材料的T5%、T50%、Tmax分别提高了31、13、17℃。降解性能上,添加NCC有助于纳米复合材料降解,降解率会随着NCC含量增加而增大,当纳米纤维素的含量在2.5%时,纳米复合材料可以在100天降解69%。抗老化性能上,NCC很好的改善了PPC的抗老化性,并且NCC的添加量越多,纳米复合材料的抗老化性能越好。本课题利用NCC作为PPC的改性剂,制备的PPC/NCC纳米复合材料表现出优异的综合性能,并能较好的适用于包装领域,并对解决当前环境问题,实现可持续发展具有积极意义。
[Abstract]:With the improvement of people's living standard, plastic packaging, as the main force of packaging industry, has played an irreplaceable role in the fields of daily necessities and food. However, the environmental pollution caused by plastics is becoming more and more serious because of the difficulty of recycling and the difficulty of degradation. An effective way to solve this problem is to develop new "green" packaging materials which are safe and non-toxic and biodegradable. Poly (propyllidene carbonate) (PPC) is a completely degradable and environmentally friendly plastic synthesized from "greenhouse gas" carbon dioxide and propylene oxide. It is one of the most promising environmental plastics at present. This material can not only make full use of "greenhouse gas" carbon dioxide to convert into environment-friendly degradable plastics, but also avoid the secondary pollution caused by traditional plastics. In addition, the application of plastics has been expanded to alleviate the consumption of petroleum resources to a certain extent. Nanocellulose (NCC) is a new functional material with broad prospect in the field of functional materials because of its wide source of raw materials and low cost. In this paper, microcrystalline cellulose (PPC) was prepared by sulfuric acid hydrolysis method and used as modifier of PPC to prepare an environment-friendly PPC/NCC nanocomposite suitable for packaging. It has laid a foundation for its mass production and application as a new type of plastic packaging material. The optimum conditions for the preparation of NCC were determined as follows: the concentration of sulfuric acid was 65 wt.The hydrolysis temperature was 45 鈩，

本文编号：1819518