阿姆斯特丹大学的研究人员在生物基聚酯的生产方面迈出了一大步
这一突破可能最终为商业化生物塑料铺平道路
生物塑料为石油基塑料提供一种有前景的替代品
石油设备网讯 据油价网2022年12月17日报道，阿姆斯特丹大学的研究人员在生产完全生物基刚性聚酯方面迈出了重要一步。这项工艺取代了石油生产非常坚固和耐用的生物基塑料，这些塑料是由已经在商业上可用的塑料积木制成的。
在最近发表在《自然通讯》上的一篇论文中，由阿姆斯特丹大学Gert-Jan Gruter教授领导的工业可持续化学小组的研究人员提出了一种简单而创新的合成策略，以克服生物基仲二醇固有的低反应性，并获得具有非常好的机械和热性能的聚酯，同时具有高分子量。
这项研究是在RIBIPOL项目内进行的，由荷兰科学研究组织NWO资助，由业界，特别是全球知名玩具制造商乐高玩具公司和荷兰树脂制造商Avantium公司提供研究资金。乐高玩具公司支持这个研究项目，作为其塑料砖寻找非化石替代品的一部分。Avantium公司对瓶子和薄膜应用很感兴趣。
这篇论文的第一作者是博士生丹尼尔·温兰德，他在今年10月27日毕业。共有5名博士生参与了RIBIPOL项目，其中2人最近完成了论文答辩。
一般来说，聚酯塑料是由小的二醇和二酸分子合成的。这些单体在缩合反应中相互耦合，以交替的方式形成分子组成的长聚合物链。宏观材料的性质既来自组成聚合物链的积木的数量，也来自单体的固有性质。特别是它们的硬度是结实、坚固和耐用塑料的关键。在这方面，葡萄糖衍生的二醇异山梨酯在潜在的生物基单体中是独特的。它具有非常刚硬的分子结构，已经在工业上可用。
然而，异山梨酯是相当不活跃的，在过去的20年里，获得有用的异山梨酯基聚酯是相当具有挑战性的。要获得足够长的聚合物链(以达到一定的延展性)，同时加入足够多的异山梨酯(以达到坚固耐用的材料)，几乎是不可能的。
加入芳香基
温兰德和他的RIBIPOL项目同事通过在聚合过程中加入芳香基来克服这一僵局。这导致了反应性芳香基的原位形成和缩聚过程中端基反应性的显著增强，缩聚是聚酯合成的最后阶段，当异山梨酯低反应性抑制传统熔体聚酯反应中的链生长时。
结果，高分子量的材料可以与高分数的生物基，刚性仲二醇掺入，甚至高达100mol%。以异山梨酯和琥珀酸为原料，可以首次生产出高分子量聚琥珀酸异山梨酯。
由此产生的坚固塑料在耐热性方面优于现有的塑料，如PET。异山梨酯基聚合物也显示出有希望的屏障和机械性能，可以优于普通的化石基材料。
本文所述的新型聚合方法具有操作简单和使用标准聚酯合成设备的特点。这种方法适用于现有的和新的聚酯成分。研究人员预测，基于低反应性单体的以前无法获得的聚酯组合物的探索，以及类似方法在聚酰胺和聚碳酸酯等其他类别聚合物中的应用。
世界原油产量中相当可观的一部分是用来生产塑料的。虽然这一突破的规模并不大，也不包括目前生产的大量塑料，但它确实为更多的生物基而不是化石基原料打开了大门。
虽然新闻稿没有给我们一堆关于聚酯在世界经济中的数字，但也没有描述任何生产成本，让我们感受到这项研究提供的实用性。人们确实希望生产过程至少具有竞争力。
一些利基市场很可能会欢迎这样的结果。即使与PET家族的塑料相比，这种巨大强度的断言也是一个非常令人鼓舞的迹象。
李峻 编译自 油价网
原文如下：
New Breakthrough Could Pave The Way For Commercial Bioplastics
· Amsterdam researchers have made a major leap forward in the production of biobased polyesters.
· The breakthrough could ultimately pave the way for commercial bioplastics.
· Bioplastics offer a promising alternative to petroleum-based plastics.
Researchers at Universiteit van Amsterdam made an important step towards the production of fully biobased, rigid polyesters. The process replaces petroleum in the production of very strong and durable biobased plastics from building blocks that are already commercially available.
In a recent paper published in Nature Communications, researchers at the Industrial Sustainable Chemistry group led by Prof. Gert-Jan Gruter presented a simple, yet innovative, synthesis strategy to overcome the inherently low reactivity of biobased secondary diols and arrive at polyesters that have very good mechanical- and thermal properties, and at the same time high molecular weights.
The research was carried out within the RIBIPOL project funded by the Dutch Research Council NWO with contributions from industry, notably LEGO and Avantium. The LEGO toy company supported the project as part of the search for non-fossil alternatives for its plastic bricks. Avantium is interested in bottle- and film applications.
First author of the paper is PhD student Daniel Weinland, who graduated on October 27th, 2022 . In total, 5 PhD students are involved in the RIBIPOL project, of which 2 have defended their thesis recently.
In general, polyester plastics are synthesized from small dialcohol and diacid molecules. These monomers are coupled in a condensation reaction, resulting in a long polymer chain of molecular building blocks in an alternating fashion. The macroscopic material properties result both from the number of building blocks that make up the polymer chain, and from the inherent properties of the monomers. In particular their rigidity is key to a firm, strong and durable plastic. In this regard, the glucose-derived dialcohol isosorbide is unique among potential biobased monomers. It has a very rigid molecular structure and is already industrially available.
However, isosorbide is rather unreactive, and in the past two decades it has proven quite challenging to obtain useful isosorbide-based polyesters. It was nearly impossible to arrive at sufficiently long polymer chains (to achieve a certain ductility) while incorporating sufficiently high amounts of isosorbide (to arrive at a strong and durable material).
Incorporating an aryl alcohol
Weinland and his RIBIPOL colleagues have overcome this impasse by incorporating an aryl alcohol in the polymerization process. This leads to in situ formation of reactive aryl esters and a significant enhancement of the end group reactivity during polycondensation, the last stage of polyester synthesis when isosorbides low reactivity inhibits chain growth in traditional melt polyesterification.
As a result, high molecular weight materials could be produced with incorporation of high fractions of the biobased, rigid secondary diol, even up to 100 mol%. For the first time high molecular weight poly(isosorbide succinate) could be produced, the polyester obtained from isosorbide and succinic acid.
The resulting strong plastics outperform existing plastics like PET in terms of heat resistance, which is for instance relevant for reuse – think of washing bottles that takes place at a scalding 85° C. The isosorbide-based polymers also show promising barrier and mechanical properties that can outperform common fossil-based materials.
The novel polymerisation approach described in the paper is characterized by operational simplicity and the use of standard polyester synthesis equipment. It suits both existing and novel polyester compositions; the researchers foresee exploration of previously inaccessible polyester compositions based on monomers with a low reactivity but also the application of similar methods in other classes of polymers such as polyamides and polycarbonates.
A quite noteworthy amount of the world’s petroleum production is destined for producing plastics. While this breakthrough isn’t on a grand scale or encompass a massive share of the plastics made right now it does crack the door open for more biobased rather than fossil based feedstocks.
While the press release spared us a bunch of numbers about polyesters in the world’s economy they also didn’t describe any costs of production that would give us a sense of the practicality the research offers. One does hope that the production process is at least competitive.
There is likely some niches of market that will welcome the results. The assertion of great strength, even compared to the PET family of plastic is a very encouraging sign.
