Editorial Cite This: Macromolecules 2017, 50, 9525−9527
Celebrating 50 Years of Macromolecules the past five decades. This is not the place to go in detail into the justification for these selections, but a few comments are in order. The top choice will likely engender little argument. Until the 1980s, model polymers were prepared almost exclusively by living anionic polymerization. This greatly restricted both the polymers that could be prepared and the number of practitioners capable of preparing them. The second choice highlights one of the great strengths of Macromolecules: the intimate and productive interactions among synthesis, materials characterization, and theory. The self-consistent mean-field theory can now provide essentially quantitative comparisons of the free energies of competing phases; modern synthetic tools greatly expand the palette of useful monomers; advanced scattering and microscopy tools reveal the amazing subtleties in the way block polymers pack to fill space. Items 3, 6, and 9 represent substantial conceptual advances in which the late Pierre-Gilles de Gennes played the key role. The polymer brushchains densely tethered to a plane, line, or point unifies our understanding of a host of practical systems, including polymer-stabilized particles for delivery of therapeutics and responsive surfaces. The reptation concept has led to near-quantitative predictions of the linear and nonlinear rheological properties of entangled polymers, thereby impacting almost all polymer processing operations. The random phase approximation allows quantitative interpretation of the phase behavior of arbitrary polymer mixtures. In Table 2, I offer a list of the top ten experimental tools that were either invented or became much more broadly available
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s you are by now well aware, we are just concluding the 50th anniversary of Macromolecules. The journal has published a series of 24 50th Anniversary Perspectives by leading experts around the world, which we hope will become a great resource to the community for years to come.1−24 These papers provide personal insights into many of the great developments in polymer science, with a particular view toward the future. I encourage you to read these at your leisure, and to facilitate their broader accessibility, we intend to publish a virtual issue containing all 24 papers in 2018. This month also marks another notable milestone in the history of polymer sciencethe release of the movie “The Graduate”, which contains the iconic scene “I just want to say one word to you. Just one word.... Are you listening?... Plastics.” The former milestone has been celebrated around the world, with joint symposia at the 25th Anniversary Meeting of the Society of Polymer Science of India, the 66th Meeting of the Society of Polymer Science, Japan, the 41st Meeting of the Polymer Society of Korea, and the 15th Pacific Polymer Congress in China. There were also landmark symposia at the ACS National Meetings in San Francisco and Washington, DC. The vitality of polymer science around the globe was made abundantly clear to me at these various conferences, which were all well attended and featured lively participation by younger researchers. Note also that the societies in India and Korea (as well as the Pacific Polymer Federation) were not even in existence when Macromolecules was launched. At the same time, as the worldwide polymer industry approaches $500 billion in annual sales, we may safely conclude that the prediction from the “The Graduate” was in fact much more than prescient. I had the privilege of speaking at the above-mentioned international events (OK, actually I invited myself, but let us not quibble) under the general title “50 Years of MacromoleculesWhat Have We Learned?” In so doing, I was motivated to prepare some “Top Ten Lists”, which were apparently received with not inconsiderable interest. Accordingly, I will take this opportunity to reproduce them here, for the curious. As a disclaimer, this is a largely subjective exercise, and no doubt you might reach quite different conclusions. Table 1 presents my Top Ten Achievements in our field over
Table 2. Top Ten New Experimental Techniques 1. 2. 3. 4. 5. 6. 7. 8. 9. 10.
during the past half-century. This list too is subjective, although again I doubt there would be much argument about item 1. Virtually every polymer laboratory in the world has access to SEC. Small-angle neutron scattering is a specialized technique, to be sure, but the information it providese.g., on individual chain conformations, distribution, and dynamics in bulk materialscannot be obtained in any other way. Both rheological measurements and dynamic light scattering used to be very specialized techniques; the practitioner had to build a dedicated apparatus. Now they have been democratized to the point where their application is routine. (On the other hand, some might note that with democratization comes the freedom
Table 1. Top Ten Achievements 1. 2. 3. 4. 5. 6. 7. 8. 9. 10.
achievements
references
controlled radical polymerization block copolymer phase diagram the polymer brush (semi)conducting polymers controlled nonlinear architectures reptation model polymers for biomedical applications olefin polymerization catalysis: metallocenes and ROMP random phase approximation for blends dynamic/reversible/supramolecular polymers
7, 18, 19 1 11 13 4
© 2017 American Chemical Society
size exclusion chromatography small-angle neutron scattering dynamic light scattering commercial rheometers synchrotron SAXS solid-state NMR cryogenic transmission electron microscopy MALDI mass spectrometry atomic force microscopy neutron and X-ray reflectivity
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DOI: 10.1021/acs.macromol.7b02507 Macromolecules 2017, 50, 9525−9527
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(2) Liang, Y.; Li, L.; Scott, R. A.; Kiick, K. L. 50th Anniversary Perspective: Polymeric Biomaterials: Diverse Functions Enabled by Advances in Macromolecular Chemistry. Macromolecules 2017, 50, 483−502. (3) Kumar, S. K.; Benicewicz, B. C.; Vaia, R. A.; Winey, K. I. 50th Anniversary Perspective: Are Polymer Nanocomposites Practical for Applications? Macromolecules 2017, 50, 714−731. (4) Polymeropoulos, G.; Zapsas, G.; Ntetsikas, K.; Bilalis, P.; Gnanou, Y.; Hadjichristidis, N. 50th Anniversary Perspective: Polymers with Complex Architectures. Macromolecules 2017, 50, 1253−1290. (5) Spiess, H. W. 50th Anniversary Perspective: The Importance of NMR Spectroscopy to Macromolecular Science. Macromolecules 2017, 50, 1761−1777. (6) Baer, E.; Zhu, L. 50th Anniversary Perspective: Dielectric Phenomena in Polymers and Multilayered Dielectric Films. Macromolecules 2017, 50, 2239−2256. (7) Ouchi, M.; Sawamoto, M. 50th Anniversary Perspective: MetalCatalyzed Living Radical Polymerization: Discovery and Perspective. Macromolecules 2017, 50, 2603−2614. (8) Knychała, P.; Timachova, K.; Banaszak, M.; Balsara, N. P. 50th Anniversary Perspective: Phase Behavior of Polymer Solutions and Blends. Macromolecules 2017, 50, 3051−3065. (9) Tritschler, U.; Pearce, S.; Gwyther, J.; Whittell, G. R.; Manners, I. 50th Anniversary Perspective: Functional Nanoparticles from the Solution Self-Assembly of Block Copolymers. Macromolecules 2017, 50, 3439−3463. (10) Schneiderman, D. K.; Hillmyer, M. A. 50th Anniversary Perspective: There Is a Great Future in Sustainable Polymers. Macromolecules 2017, 50, 3733−3749. (11) Chen, W.-L.; Cordero, R.; Tran, H.; Ober, C. K. 50th Anniversary Perspective: Polymer Brushes: Novel Surfaces for Future Materials. Macromolecules 2017, 50, 4089−4113. (12) Russell, T. P.; Chai, Y. 50th Anniversary Perspective: Putting the Squeeze on Polymers: A Perspective on Polymer Thin Films and Interfaces. Macromolecules 2017, 50, 4597−4609. (13) Swager, T. M. 50th Anniversary Perspective: Conducting/ Semiconducting Conjugated Polymers. A Personal Perspective on the Past and the Future. Macromolecules 2017, 50, 4867−4886. (14) Blasco, E.; Sims, M. B.; Goldmann, A. S.; Sumerlin, B. S.; Barner-Kowollik, C. 50th Anniversary Perspective: Polymer Functionalization. Macromolecules 2017, 50, 5215−5252. (15) Park, J. H.; Rutledge, G. C. 50th Anniversary Perspective: Advanced Polymer Fibers: High Performance and Ultrafine. Macromolecules 2017, 50, 5627−5642. (16) Lotz, B.; Miyoshi, T.; Cheng, S. Z. D. 50th Anniversary Perspective: Polymer Crystals and Crystallization: Personal Journeys in a Challenging Research Field. Macromolecules 2017, 50, 5995−6025. (17) McKenna, G. B.; Simon, S. L. 50th Anniversary Perspective: Challenges in the Dynamics and Kinetics of Glass-Forming Polymers. Macromolecules 2017, 50, 6333−6361. (18) Grubbs, R. B.; Grubbs, R. H. 50th Anniversary Perspective: Living PolymerizationEmphasizing the Molecule in Macromolecules. Macromolecules 2017, 50, 6979−6997. (19) Perrier, S. 50th Anniversary Perspective: RAFT Polymerization A User Guide. Macromolecules 2017, 50, 7433−7447. (20) Galizia, M.; Chi, W. S.; Smith, Z. P.; Merkel, T. C.; Baker, R. W.; Freeman, B. D. 50th Anniversary Perspective: Polymers and Mixed Matrix Membranes for Gas and Vapor Separation: A Review and Prospective Opportunities. Macromolecules 2017, 50, 7809−7843. (21) Creton, C. 50th Anniversary Perspective: Networks and Gels: Soft but Dynamic and Tough. Macromolecules 2017, 50, 8297−8316. (22) Herbert, K. M.; Schrettl, S.; Rowan, S. J.; Weder, C. 50th Anniversary Perspective: Solid-State Multistimuli, Multiresponsive Polymeric Materials. Macromolecules 2017, 50, 8845−8870. (23) Wang, Z.-G. 50th Anniversary Perspective: Polymer ConformationA Pedagogical Review. Macromolecules 2017, 50 (23), 9073− 9114. (24) Muthukumar, M. 50th Anniversary Perspective: A Perspective on Polyelectrolyte Solutions. Macromolecules 2017, 50, in press.
for misuse!) One omission from this listcomputer simulationsdeserves extra comment. The power of both hardware and current algorithms has elevated simulations to the level of an essential family of techniques, both for fundamental understanding and for prediction. In short, if I could overcome my inherent myopia, which prevents me from classifying computer simulations as an experimental technique, I would place it high on this list. The technological and intellectual achievements of the past five decades are tremendous, but much remains to be done. Accordingly, ten “grand challenges” for our field are proposed in Table 3. They range from the eminently practical to the Table 3. Top Ten Current Challenges 1. 2. 3. 4. 5. 6. 7. 8. 9. 10.
theory of polymer crystallization theory of the glass transition sustainable routes to commodity polymers monomer sequence control better membranes for separations (water, gases, ions, etc.) competitive (cost and performance) sustainable polymers polymers for personalized medicine fundamental understanding of ion-containing polymers robust polymer systems for plastic electronics scale-up and processing to retain/perfect nanostructure
primarily academic, yet most will be familiar to all. The first two merit some explanation. I find it remarkable that the landmark theories of crystallization, due to Hoffmann and Lauritzen, and the polymer glass transition, due to Gibbs and DiMarzio, and now both well over 50 years old, and yetso far as I can judgeexperts do not believe them very much, but they do not uniformly subscribe to any other theory either. Every time I teach an introductory course in polymers, I am reminded of this unsatisfying state of affairs, whereas in almost any other classical area of polymer science we can point to a theoretical approach that captures at least the essence of the basic problem, with its strengths and shortcomings well established. Clearly, the lack of such theories has not materially hindered the development and application of countless new polymer materials, yet I contend that these two problems represent important “high hanging fruit”. One final observation on the first half-century of Macromolecules: remarkably, at least two individuals coauthored papers in both Volume 1 (1968) and Volume 50 (2017). These distinguished members of our community are Ed Samulski (University of North Carolina)25,26 and Jacques Roovers (National Research Council of Canada).27,28 They deserve a hearty round of applause for their longevity as well as for their manifold contributions to the field extending over more than 50 years!
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Timothy P. Lodge, Editor AUTHOR INFORMATION
ORCID
Timothy P. Lodge: 0000-0001-5916-8834 Notes
Views expressed in this editorial are those of the author and not necessarily the views of the ACS.
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REFERENCES
(1) Bates, C. M.; Bates, F. S. 50th Anniversary Perspective: Block PolymersPure Potential. Macromolecules 2017, 50, 3−22. 9526
DOI: 10.1021/acs.macromol.7b02507 Macromolecules 2017, 50, 9525−9527
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(25) Samulski, E. T.; Tobolsky, A. V. Some Unusual Properties of Poly(γ-benzyl L-glutamate) Films Cast in Strong Magnetic Fields. Macromolecules 1968, 1, 555−557. (26) Wutz, C.; Tanner, M. J.; Brookhart, M.; Samulski, E. T. Where Are the Chain Ends in Semicrystalline Polyethylene? Macromolecules 2017, 50, 9066−9070. (27) Roovers, J. E. L.; Bywater, S. The Polymerization of Isoprene with sec-Butyllithium in Hexane. Macromolecules 1968, 1, 328−331. (28) Jeong, Y.; Jin, Y.; Chang, T.; Uhlik, F.; Roovers, J. Intrinsic Viscosity of Cyclic Polystyrene. Macromolecules 2017, 50, 7770−7776.
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DOI: 10.1021/acs.macromol.7b02507 Macromolecules 2017, 50, 9525−9527
