New Polymers: Beautiful Structures, But How Can We Bring Them to the Market?

Precision Polymers

Today the term “macromolecular engineering”, coined in the 1980s, has been replaced by the term “precision polymers”. It is possible, by various beautifully developed polymerization methods, to control to a large extent molar mass, dispersity, end groups, and the polymer architecture, in addition to stereoregularity, and even (within certain limits) the monomer sequence. A huge variety of carefully designed polymer structures has been reported, constructed from various repeating units and building blocks. Thus, polymer chemists are close to realizing macromolecules and assemblies that not only reach perfection, but are also nearly as complex as biological structures. In addition, the exploitation of the potential of organic chemistry has led to macromolecules with previously unimaginable function. But so far only a few features of those polymeric structures have been translated into larger-scale technical products, such as controlled tacticity and thus crystallinity, as well as achieving specific nanomorphology leading to desired mechanical properties through block and graft copolymer structures. Certainly, the ability to precisely realize well-defined polymer structures has led to a huge amount of new knowledge and understanding of structure–property relationships and is, in addition, the basis for controlling morphology and self-assembly in materials. It is only by being able to precisely introduce functionality and control macromolecular size and dispersity that we can derive and verify theoretical prediction and ensure sufficient fundamental knowledge gain for future, unpredictable innovations.

In order to bring all this beautiful and extensive knowledge into new polymer products and technologies, not even on a large scale, but also as specialty functional polymers for small-scale applications, an important additional step is required. The achieved complexity should be reduced to the essential features for the desired function, thus significantly reducing the synthetic effort and costs. This starts with using feasible and available monomer structures, technically attractive polymerization methods, and in particular low-cost or highly reduced purification steps. However, who is carrying out, and more importantly, who is paying for that step? For the academic world, this is not attractive, because for being able to publish in high-impact journals or getting attractive funding and good PhD students, it is certainly not sufficient to report an improved purification method or a cheaper monomer synthesis. Unfortunately, it is no longer “fancy” to study polymerization methods with regard to reproducibility, reaction kinetics, energetics, or to look for a suitable reactor design or efficient polymerization procedures. A lucky exception is the field of catalysis, which is in all aspects highly attractive for monomer synthesis, exploitation of new (e.g., renewable) resources, as well as for effective polymerization procedures with easy translation into technical processes. However, whereas sustainability is an attractive feature for funding agencies, simply reducing complexity and costs is not. This is no longer considered to be an aspect of precompetitive public funding but a major task of industrial research.

Originally, the strong chemical industry especially in Germany has done exactly that: translating academic knowledge into industrial processes and cost-effective polymeric products. But today, the big chemical companies are reducing their portfolio of large-scale commodity and engineering polymers: customized products for the processing industry are less frequently developed because only low profits are expected, and small-scale functional polymers have to be developed and produced more and more directly by the original equipment manufacturers (OEMs) or brand owners, since the profit is gained with the final formulation, part, or device, not the raw polymeric material. But those companies, being active, for example, in the automotive, IT, energy, or biomedicine sector, often lack adequate chemistry- and chemical-engineering-oriented research facilities and knowledge to develop a cost-effective production of precision polymers. This might provide room for new service providers in contract development and toll manufacturing for specialty polymers.

The challenge for the future of precision and functional polymers is therefore translating the high-level academic knowledge with excellent synthetic capabilities into cost-effective, scalable, and processible polymer products, having the needed function and property for the desired application, but not more. No customer will pay just for precision and beauty, only for a working product. And a new precisely synthesized multifunctional polymer architecture will not automatically lead to a new technology.

Nanomaterials

Besides precision polymers, control and exploitation of nanomaterials dominate the field of polymer science in the 21st century. This is accompanied by huge progress in visualizing nanosized soft or hybrid materials as well as by accessing properties on the nanoscale. Precision functional polymers can be assembled into defined nanomorphology in bulk, or into nanoparticles, nanocapsules, or nanorods in solution; various soft and hard nano-objects can be effectively incorporated into polymer matrices for achieving unaccounted new property and functionality.

Extensive progress in understanding and controlling surface interactions ensures that translation into innovative functional nanocomposites is accomplished relatively fast, and the first products are already on the market. Importantly, the development of cost-effective processing techniques, rheology expertise, and intensive understanding of structure–property relations are additional essential prerequisites for successful knowledge transfer. Such knowledge is not only valid for innovations based on functional nanocomposites, but is also highly fruitful for achieving the optimal bulk morphology in blends and for various functional composites and lightweight-polymer-based structures. Furthermore, the field of additive manufacturing will certainly bring highly interesting research tasks for academia as well as industry with regard to broadening the material portfolio including concepts for fillers, additives, and surface engineering, and will broaden the spectrum of materials as well as their potential applications.

A great challenge is, however, the exploitation of the various polymeric nanostructures as well as responsive polymeric architectures as individual nanomaterials in technical devices and applications, for example, as sensors and actuators in optoelectronics, medical devices, or even in medical treatment. Here scalability and reproducibility of the preparation of the complex macromolecules and assemblies need strong efforts and the development of suitable processing technology. Most importantly, the nanoscale effect can only be exploited when scientists succeed to combine the nanoworld with the macroworld in a cost-efficient way, being not only competitive but superior to existing material and technology solutions. Concepts of dynamic bonding and molecular recognition in self-assembly may have high potential in this regard, however, again much additional research effort, manpower, and funding are needed after the first proof-of-concept for achieving technical solutions. This will need strong public–private partnerships between polymer chemists and physicists, engineers, device producers, and end users, in a way not covered by present funding schemes or collaborative work.

Perspectives

Let me not be misunderstood: the achievements of polymer science in recent years have been amazing, and much more can be expected to come. I highly value academic research as I am part of it, and I consider it absolutely essential that we have the freedom as well as the funding to look for beauty, complexity, and precision, and to develop the tools to realize respective complex polymeric structures, hybrids, and assemblies, and to assess, understand, and model their properties on the nanoscale as well as in bulk.

Only by having the suitable tools in hand and with a deep understanding of structure–property relationships, can the future of successful and competitive polymer-material development be assured. Even though not all beautiful synthetic schemes and complex structures are transferred in their entirety into technical use, the gained knowledge still brings huge progress. In this way, improved commodity polymers are now able to cover applications of engineering or even high-performance polymers, high performance in polymers can be combined with multifunctionality or even self-healing features, monomers for engineering polymers can be derived in a cost-effective way from renewable resources, and new applications are exploited for new functional polymer materials.

Still, I feel it is necessary that we become more aware that significant efforts are not only necessary, but also have to be recognized by the academic community, for bringing new concepts in polymer science from the first proof-of-concept into technical use. Important academic research and training in reaction engineering and kinetics should not be neglected. Complexity reduction in combination with new alliances and cooperation schemes might be needed (including the financial involvement of OEMs in the production of custom-made materials), especially in the field of small-scale functional polymeric (nano)materials, for developing market-ready products.