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从源头探索高分子材料的绿色化
来源:网络 | 作者:Bungechem | 发布时间: 1611天前 | 370 次浏览 | 分享到:
随着高科技的迅猛发展,高分子材料在各行各业的应用日趋增多,而高分子材料的不可降解性和低回收利用率对环境造成的危害已不可低估,现已成为固体废弃物处理中的一个世界性棘手难题。
With the rapid development of high technology, the application of polymer materials in all walks of life is increasing day by day, and the harm to the environment caused by the non-degradability and low recycling rate of polymer materials cannot be underestimated. a worldwide thorny problem.

    高分子材料是指单体通过加聚反应或缩聚反应得到的聚合物而形成的材料,如各种塑料、橡胶等,它也是制造纺织合成纤维的原料。
    随着高科技的迅猛发展,高分子材料在各行各业的应用日趋增多,而高分子材料的不可降解性和低回收利用率对环境造成的危害已不可低估,现已成为固体废弃物处理中的一个世界性棘手难题。
    绿色高分子材料是一种对环境友好的高分子材料。
    “绿色”是指从高分子材料合成的源头——单体着手,选择对环境友好的单体材料及合成工艺,并且考虑合成的高分子材料对环境的相容性(即在较短的时间内自然降解或解聚)及产品的生命周期性(产品使用后的回收利用)。
    虽然当前高分子材料的绿色化还主要表现在可降解性研究,但寻找更加绿色环保、可持续的合成原料一直是科学家们追求的目标。尤其是利用“温室气体”CO2合成高分子材料的研究,近年来频频出现在世界**学术期刊上。
    近日,加拿大多伦多大学某团队发布了一项研究成果,称其已经找到了较有效地将CO2转化为乙烯(ethylene)的条件。而乙烯便能再被用来制造聚乙烯(polyethylene),也就是全球年产量约8000万t、现今较普遍使用的塑料。
据了解,这项研究的核心工作是CO2还原反应的过程。在催化剂的辅助下,通过电流和化学反应将CO2转化为其他化学物质。在这种反应中,许多金属都可以做为催化剂,如金、银和锌能够催化生成CO,而锡和钯可以催化生成甲酸,铜则能催化产生乙烯。
    运用Canadian Light Source科学家Tom Regier开发的独特设备,研究人员能够实时研究整个二氧化碳还原反应过程中铜催化剂的型态、形状以及化学环境。进而确认乙烯生产较大化的条件,并通过调整催化剂来达成较大程度地提高乙烯生产量、同时将甲烷产量降至较低目的。
这项研究已经公布在《自然》系列旗下较新冠名期刊《自然-催化》(Nature Catalysis)中。
    在此之前,美国斯坦福大学的一个研究小组也在《自然》杂志登载的一篇论文中,提出了一种可以把二氧化碳以及农作物残留物等植物材料转化为塑料的研究成果。
    研究人员混合碳酸盐、CO2和由糠醛衍生获得的糠酸,将它们加热至200℃,呈现熔盐状态,持续5h后,熔盐混合物总量的89%会转化为2,5-呋喃二甲酸,进而生产可在一定程度上替代聚对苯二甲酸乙二酯的聚呋喃二甲酸乙二酯(PEF)。而2,5-呋喃二甲酸与对苯二甲酸不同,可以是生物材料的衍生物。
除此之外,以淀粉等天然物质为基础在微生物作用下生成的生物塑料,具有可再生性,因此环保。


The polymer material refers to the material formed by the polymer obtained by the addition polymerization or polycondensation reaction of the monomer, such as various plastics, rubber, etc. It is also the raw material for the manufacture of textile synthetic fibers.

    With the rapid development of high technology, the application of polymer materials in all walks of life is increasing day by day, and the harm to the environment caused by the non-degradability and low recycling rate of polymer materials cannot be underestimated. a worldwide thorny problem.

    Green polymer material is an environmentally friendly polymer material.

    "Green" refers to starting from the source of polymer material synthesis-monomer, selecting environmentally friendly monomer materials and synthesis processes, and considering the compatibility of the synthesized polymer materials to the environment (that is, in a short period of time natural degradation or depolymerization) and the life cycle of the product (recycling of the product after use).

    Although the current greening of polymer materials is mainly reflected in the study of degradability, the search for more green and sustainable synthetic raw materials has always been the goal of scientists. In particular, the use of "greenhouse gas" CO2 to synthesize polymer materials has frequently appeared in the world's leading academic journals in recent years.

    Recently, a team from the University of Toronto in Canada released a research result, saying that it has found the conditions for converting CO2 into ethylene more efficiently. And ethylene can then be used to make polyethylene (polyethylene), which is a plastic that is more commonly used today with an annual output of about 80 million tons.

It is understood that the core work of this research is the process of CO2 reduction reaction. With the aid of catalysts, CO2 is converted into other chemicals through electrical current and chemical reactions. In this reaction, many metals can be used as catalysts, such as gold, silver and zinc can catalyze the production of CO, while tin and palladium can catalyze the production of formic acid, and copper can catalyze the production of ethylene.

    Using a unique device developed by Canadian Light Source scientist Tom Regier, the researchers were able to study in real time the type, shape, and chemical environment of the copper catalyst throughout the carbon dioxide reduction reaction. Furthermore, the conditions for maximizing ethylene production were confirmed, and by adjusting the catalyst, the purpose of maximizing ethylene production and reducing methane production to a lower level was achieved.

The research has been published in the newer titled journal Nature Catalysis, part of the Nature series.

    Prior to this, a research team from Stanford University in the United States also proposed a research result that can convert plant materials such as carbon dioxide and crop residues into plastics in a paper published in the journal Nature.

    The researchers mixed carbonate, CO2, and furoic acid derived from furfural and heated them to 200°C to present a molten salt state. After 5 hours, 89% of the total molten salt mixture was converted to 2,5-furandi Formic acid, which in turn produces polyethylene furandicarboxylate (PEF), which can replace polyethylene terephthalate to a certain extent. And 2,5-furandicarboxylic acid, unlike terephthalic acid, can be a derivative of biological materials.

In addition, bioplastics generated under the action of microorganisms based on natural substances such as starch are renewable and therefore environmentally friendly.