高分子●高分子●●●展望 COVER STORY Vo1.57,No.672 Jan.1,2008●● 展望COVER STORY v・1.57,

Polymers:Where the Sciences Meet-An Editor's Reflections

Text by Peter GOLITZ

The Past: The past 25 years, over which I have been the Editor-in-chief of Angewandte Chemie, have seen a dramatic development of polymer science. Around 1980, polymer or macromolecular science was certainly a lively field, but, based on the definition of the term "polymers",U it was much more restricted; it was practiced by polymer chemists, physicists and engineers, and the interaction with other sciences in general or other fields of chemistry in particular was rather limited. All the main classes of polymers existed already, and there was an extensive industry behind this science, a fact that has not changed. Structural polymers abounded, and through blending of different polymer classes new applications were sought. Functional polymers were in their infancy. At just about the time Heeger, MacDiarmid, and Shirakawa had developed conducting polymers,4 3) polymers were occasionally being used as supports for organic reactions,41 and the use of polymers in medicine was more a vision.51 The realm of biomacromolecules—oligonucleotides, proteins, carbohydrates—was very much separated and researched by biochemists, structural biologists etc. Today: These days a Google search for key polymer-related terms delivers impressive results (Table 1). Polymer science knows no boundaries, and interactions with other disciplines are commonplace!

Table 1. Number of Hits in Google for Polymer-Related Terms

Polymers 53,400,000 Polymer Engineering 46,300,000 Polymer Chemistry 41,100,000 Polymer Physics 3,960,000 Polymer Medicine 2,010,000 Polymer Life Sciences 1,900,000 Polymer Biology 1,850,000 Macromolecules 8,490,000 Biomacromolecules 1,650,000 Biopolymers 2,450,000

Most striking is perhaps the fact that traditional "petroleum-based" polymers and biopolymers of all classes have come together: Hybrid polymers or block copolymers with bioblocks are under intensive investigation in order to produce biocompatible and/or biodegradable materials, bio-analytical tools (sensors) or drug delivery vehicles; there are also high expectations for such compounds in regenerative medicine.0 A lot of excitement is created by research at the interface of polymer science with physics and electronic/ optical/magnetic engineering.7) For whatever physical property one can envision for a polymer, hybrids with other compound classes can be assembled to meet the requirements. Without polymers, the whole field of

Peter GOlitz, Dr. ([email protected]) Editor-in-Chief, Angewandte Chemie. Wiley-VCH Boschstrasse 12 69469 Weinheim Germany

20 高分子 57巻 1月号 (2008年) microfluidics would not thrive as it currently does.8) But polymers are not only making an impact beyond chemistry—on medicine and the life sciences, physics and engineering—they are also much more commonplace in all the chemistry subdisciplines today. The interface between organic and polymer chemistry has always been most important, and it is no wonder that the father of polymer chemistry, Hermann Staudinger, was a well-respected organic chemist in his early career.9) However, the border between organic and polymer chemistry has become totally blurred. Just to name a few topics: 1. Dendrimers were developed at roughly the same time by organic and by polymer chemists and are keeping many such chemists very busy these days.") 2. Click chemistry has its origin in heterocyclic synthesis; its copper-catalyzed variant has become a most popular tool in polymer synthesis as well.") 3. Olefin metathesis originated in polymer chemistry, then had a profound impact on organic synthesis, and was concomitantly further developed for the synthesis of polymer materials.') One could go on, but it should perhaps suffice here to point to two major handbooks where more examples can be found.13) Olefin metathesis does not only link organic and polymer chemistry but also organometallic chemistry, a field that has had a high impact on polymer synthesis ever since the time of Karl Ziegler and Guilo Natta.") "Metallocene catalysis" is a topic that must be mentioned in this context") as well as metal-catalyzed living radical polymerization') or atom transfer radical polymerization.') Polymers and inorganic chemistry is a less obvious marriage if one doesn't go as far as considering extended solid-state compounds as polymers. Nevertheless there are several very active lines of research in which inorganic and polymer chemists meet: Organometallic polymers,18) inorganic polymers,19) and metal —organic framework (M0F) compounds') represent some key examples. Nano is now all the craze, and polymers could well be considered as archetypical nanomolecules.') Indeed, there are plenty of nano-related activities: Inorganic nanoparticles are coated by or dispersed in polymers, and polymer nanostructures are fabricated by physical chemistry methods such as layer-by-layer deposition and lithography'). One could go on, and there is no question that polymer science is an extremely lively and interdisciplinary field —no , "field" is too small a term, it's a whole galaxy. And it will only grow in importance. More recently chemists have started to think about the materials and energy base of the future") once petroleum has become a scarce resource. The world will need more bio-based/renewable (and processable) polymers. To save energy, ever more light-weight polymers will have to be used; in order to harvest the energy of the sun—through solar cells to produce clean energy, through fuel cells etc. —polymers will be in high demand. As an editor I foresee that high-impact general chemistry journals like Angewandte Chemie will publish ever more polymer science articles in the future, and I am sure many of these will come from Japan. The society of Polymer Science, Japan (SPSJ) has provided the scientific community with a lot of support in the past and there is no doubt that this organization will play a very important role in shaping the future of polymer science in Japan and the world over.

* Since Angewandte Chemie (www .angewandte.de) is on my mind all the time, it was fitting for me to select references from this journal; they are intended for further reading and to lead to further references. I thank Stefanie Eberle, Dr. Brian Johnson, Dr. Mario Muller and Dr. Haymo Ross for their help with this article.

References

1) H. Morawetz: Difficulties in the Emergence of the Polymer Concept—an Essay, Angew. Chem. 1987, 99, 95-100; Angelo. Chem. Int. Ed. Engl. 1987, 26, 93-97. 2) A. J. Heeger: Semiconducting and Metallic Polymers; The Fourth Generation of Polymeric Materials (Nobel Lecture), Angew. Chem. 2001, 113, 2660-2682; Angew. Chem. Int. Ed. 2001, 40, 2591-2611; b) A. G. MacDiarmid: "Synthetic Metals": A Novel Role for Organic Polymers (Nobel Lecture), Angew. Chem. 2001, 113, 2649-2659; Angew. Chem. Int. Ed. 2001, 40, 2581-2590; c) H. Shirakawa: The Discovery of Polyacetylene Film: The Dawning of an Era of Conducting Polymers (Nobel Lecture), Angelo. Chem. 2001, 113, 2642 - 2648; Angew. Chem. Mt. Ed. 2001, 40, 2574-2580. 3) Gerhard Wegner: Polymers with Metal-Like Conductivity—A Review of their Synthesis, Structure, and Properties, Angelo.

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