INSIGHTS | PERSPECTIVES
cies continue to improve and the associated
monomers can be produced economically.
Fundamental research in polymerization
catalysis has been essential in the search for
highly effective systems that can tolerate
impurities, exhibit large turnover numbers,
and allow for controlled polymerizations.
The renaissance in olefin polymerization
triggered by the advent of metallocene
catalysts is today being relived with new
discrete metal acetates, carbonates, and
alkoxides and an array of organocatalysts in
the biobased polymer world.
Biobased polymers can frame the future
of plastics, provided that scientists continue to develop efficient, often catalytic,
conversion of biomass to useful polymer
ingredients; generate new and established
monomers from biomass in high yields
and purities; and discover new polymers
with outstanding properties that are comparable or superior to their petrochemical analogs. An exciting contemporary
example of this future is the substitution
of terephthalic acid with the bioderived
2,5-furandicarboxylic acid to produce a
high-performing fully biobased PET re-
placement (15). Support for this type of
research should come not only from gov-
ernment. University-industry partnerships
can be very effective at producing basic
research that is couched in the economic
realities of the polymer marketplace.
For polymers from renewable resources
to penetrate the marketplace, they must
outcompete traditional materials in both
price and performance. But as the fundamental research in the conversion of biomass to polymer precursors continues to
evolve, the resultant technologies will become more and more practical. Similarly,
as the basic research on converting these
compounds into polymers with exceptional
property, processing, and performance
profiles continues to be established, the
resultant materials will be increasingly
competitive. If the economic and environmental costs of extracting fossil resources
and converting them into plastics continue
to rise, there will likely be an inversion
point where biobased polymers become
the less expensive alternative, akin to what
is starting to happen in the renewable energy sector. Societal pressures and policies
that are conducive to environmental stewardship will only help the cause. We are
not there yet, but there is good reason to
stay the course and continue to push the
frontiers of biobased polymers for the sake
of sustainability. j
REFERENCES AND NOTES
1. E.MacArthur,Science 358, 843(2017).
2. WorldEconomic Forum,Ellen MacArthur Foundation
and McKinsey & Company, The New Plastics Economy:
Rethinking the Future of Plastics (2016); www.
3. R. Geyer, J. R. Jambeck, K. L. Law, Sci.Adv. 3, e1700782
4. J. M. Garcia, M. L. Robertson,Science 358, 870 (2017).
5. A.-C.Albertsson,M.Hakkarainen,Science 358, 872(2017).
6. A.Morschbacker, J.Macromol.Sci.C 49,79(2009).
7. O.A.Abdelrahman et al., ACS Catal. 7,1428(2017).
8. H. Chung etal., Curr.Op.Biotechnol. 36, 73 (2015).
9. J. T.Claypool,D.R.Raman,L.R.Jarboe, D.R.Nielsen, J.Ind.
Microbiol. Biotechnol. 41, 1211 (2014).
10. A.Gandini, T.M.Lacerda, A.J.F.Carvalho,E. Trovatti, Chem.
Rev. 116, 1637 (2016).
11. M.Hong, Y.-X.E.Chen., Nat.Chem. 8,42(2016).
12. F. S. Bates, C. M. Bates,Macromolecules 50, 3 (2017).
13. M.Xiong, D.K.Schneiderman, F.S.Bates,M.A.Hillmyer,K.
Zhang, Proc. Natl. Acad. Sci. U.S.A. 111, 8357 (2014).
14. M.J.Sanford, L.P.Carrodeguas, N.J.VanZee,A. W.Kleij,G.
W. Coates, Macromolecules 49, 6394 (2016).
15. A.Gandini, A.J.D.Silvestre, C.P.Neto, A.F.Sousa,M.Gomes,
J. Polym. Sci. A 47, 295 (2009).
The Center for Sustainable Polymers at the University of
Minnesota, a National Science Foundation–supported Center
for Chemical Innovation (CHE-1413862), is recognized for
support. Thanks to F. Bates, P. Dauenhauer, T. Hoye, L. Seifert,
and D. Schneiderman for feedback and suggestions. The author
has equity and royalty interests in, serves as secretary for, and
is on the board of directors of Valerian Materials, a company
involved in the commercialization of b-methyl-d-valerolactone.
The University of Minnesota also has equity and royalty interests
in Valerian Materials. These interests have been reviewed and
managed by the University of Minnesota in accordance with its
conflict of interest policies.
Petrochemical Plant based Monomers
Under development In use
By Jeannette M. Garcia1 and
Megan L. Robertson2
The environmental consequences of plastic solid waste are visible in the ver-increasing levels of global plas- tic pollution both on land and in the oceans. But although there are im- portant economic and environmental
incentives for plastics recycling, end-of-life
treatment options for plastic solid waste
are in practice quite limited. Presorting of
plastics before recycling is costly and time-intensive, recycling requires large amounts
of energy and often leads to low-quality
polymers, and current technologies cannot
be applied to many polymeric materials. Recent research points the way toward chemical recycling methods with lower energy
requirements, compatibilization of mixed
plastic wastes to avoid the need for sorting,
and expanding recycling technologies to traditionally nonrecyclable polymers.
Roughly half of the annual global production of solid plastics, or 150 million tons,
is thrown away worldwide each year. The
United States generates ~20% of the global
amount of plastic solid waste generated (1).
Not only is plastic waste residing in landfills
harmful to the environment, but it also represents missed economic opportunities. For
example, the commodity market value of the
total landfilled packaging material waste in
the United States has been estimated to be
$11.4 billion dollars; $8.3 billion of this is attributed to plastic waste (2). Furthermore,
recycling plastic for reuse saves energy compared with producing virgin materials; 1
ton of recycled plastic can save up to ~130
million kJ of energy. The potential annual
energy savings that could be achieved from
recycling all global plastic solid waste is
1IBM Almaden Research Center, Chemistry and Materials, 650
Harry Road, San Jose, CA 95120, USA. 2University of Houston,
Department of Chemical and Biomolecular Engineering,
Houston, TX 77204, USA. Email: email@example.com
Chemical advances are
increasing the proportion
of polymer waste that can
870 17 NOVEMBER 2017 • VOL 358 ISSUE 6365
Toward plant-based monomers
for commodity plastics
Most plastics are made from a small subset of
monomers. Efforts are under way to replace
petrochemical-based source materials for these
important monomers with plant-based ones.