Reaction: Benign by Design Demands Innovation
2017; Elsevier BV; Volume: 2; Issue: 1 Linguagem: Inglês
10.1016/j.chempr.2016.11.015
ISSN2451-9308
Autores Tópico(s)Nanotechnology research and applications
ResumoProf. Long joined the Department of Chemistry in 1999 after holding positions at Eastman Kodak and Eastman Chemical, and he currently serves as the director of the Macromolecules Innovation Institute at Virginia Tech. Recent recognitions include an AAAS fellowship, ACS fellowship, ACS PMSE Cooperative Research Award, ACS POLY Mark Scholar Award, and the 2015 Virginia Outstanding Scientist award. His interdisciplinary research program focuses on structure, property, processing, and performance relationships of tailored macromolecules. Current interests include materials for additive manufacturing, photo-reactive polymers, block and segmented copolymers, polymer packaging, ion-containing polymers, adhesive science, and high-performance engineering polymers. Prof. Long joined the Department of Chemistry in 1999 after holding positions at Eastman Kodak and Eastman Chemical, and he currently serves as the director of the Macromolecules Innovation Institute at Virginia Tech. Recent recognitions include an AAAS fellowship, ACS fellowship, ACS PMSE Cooperative Research Award, ACS POLY Mark Scholar Award, and the 2015 Virginia Outstanding Scientist award. His interdisciplinary research program focuses on structure, property, processing, and performance relationships of tailored macromolecules. Current interests include materials for additive manufacturing, photo-reactive polymers, block and segmented copolymers, polymer packaging, ion-containing polymers, adhesive science, and high-performance engineering polymers. In response to García’s Catalysis piece in the December issue, plastic packaging has indeed influenced every facet of our lives, from packaging sterile medical devices to supplying pure water to compromised communities. One could argue that plastic packaging is now indispensable for food and drug safety, preservation, and distribution. Plastic packages are commonly thermoplastics as opposed to thermosets, and as the term thermoplastic implies, they offer efficient molding operations at elevated temperatures for diverse package designs. For example, the ubiquitous poly(ethylene terephthalate) (PET) plastic soft drink and water bottles are efficiently injection molded and blow molded above the melting and glass transition temperatures, respectively. Thermoplastic behavior also suggests a thermal avenue for reprocessing a disposed thermoplastic package, and in 2014, recycling rates for PET soft drink bottles and jars exceeded 30%.1US Environmental Protection AgencyAdvancing Sustainable Materials Management: 2014 Fact Sheet.https://www.epa.gov/sites/production/files/2016-11/documents/2014_smmfactsheet_508.pdfDate: 2016Google Scholar There is little doubt that plastic packaging has increased both the quality and the quantity of our lives; however, our society now demands more from these everyday products as our global population grows, proclivity for convenience continually increases, and sustainability plays a more important role in new product development. Despite the immense positive impact on our lifestyles and economies, plastic packaging litters our roadsides and coastlines, pointing to a non-sustainable technology. In 2014, plastics accounted for 13% of our municipal solid waste and 18% of our municipal solid waste in landfills.1US Environmental Protection AgencyAdvancing Sustainable Materials Management: 2014 Fact Sheet.https://www.epa.gov/sites/production/files/2016-11/documents/2014_smmfactsheet_508.pdfDate: 2016Google Scholar The decades-old plastic package recycling codes (1–7) from the Society of the Plastics Industry speak to the necessity for innovation of new plastic packaging that is more “benign by design.” Does an “other” category (recycling code 7) discourage our innovative vision for future plastic packaging? Do these seven categories impede the opportunity for other, more sustainable plastic packaging to more rapidly emerge? Moreover, our society must embrace a reduce-reuse-recycle (3R) culture by recognizing the potentially negative economic and environmental impact that results in the absence of this paradigm. The packaging plastics of 1950 should not be the packaging plastics of 2050; sustainable high-performance packaging demands continued polymer innovation. PET (recycling code 1) represents a fully degradable or “reversible” polyester that is potentially converted quantitatively back to the starting diacid and diol monomers or the bis-hydroxyethyl terephthalate (BHET) precursor in the presence of a catalyst. The manufacture of polyesters does not involve organic solvents, and quantitative polycondensation processes provide products that are suitable without purification for injection or blow molding. However, polyester recycling, similar to that of many other plastic packages, does not easily tolerate the addition of performance-enhancing comonomers, residual catalyst metals, packaging labels, or label adhesives, which collectively complicate the separation process. New polyester compositions have recently emerged and include Tritan polyester (recycling code 7), which addresses societal concerns for residual or newly generated bisphenol-A (BPA) monomer from polycarbonate containers and packages.2Nelson A.M. Long T.E. Polym. Int. 2012; 61: 1485-1491Crossref Scopus (83) Google Scholar BPA polycarbonate (recycling code 7), invented decades ago, is not necessarily suitable for the high-performance dishwashers and soaps of today. Segmented polyester copolymers are also viable candidates for the replacement of plasticized poly(vinyl chloride) (PVC, recycling code 3). PVC continues to receive intense scrutiny for many reasons, ranging from the necessity of plasticizers in flexible packaging to hydrochloric acid release during reprocessing.3Yu J. Sun L. Ma C. Qiao Y. Yao H. Waste Manag. 2016; 48: 300-314Crossref Scopus (534) Google Scholar Polyesters represent an exciting area for continued innovation, including attention to new comonomers to enhance performance, more intelligent separation strategies, cost-efficient manufacturing processes, reduction of trace metallic catalysts, and monomers based on renewable feedstocks. Nature provides a vast array of alcohols, esters, and carboxylic acids that are amenable to polyester processes. Poly(lactic acid) (PLA, recycling code 7), which is based on a fermentation process to yield lactide monomer, has emerged as a replacement for petroleum-based polystyrene (PS, recycling code 6) in plastic beverage cups. Polyolefin packaging (polyethylene and propylene, recycling codes 2, 4, and 5) benefits from the synergy of tailored high performance and relatively low cost. Polyolefins offer immediate impact in healthcare, food packaging, automotive parts, and household goods. Their semi-crystalline morphology provides excellent thermal stability and superior mechanical performance. In a similar fashion to polyester manufacturing, polyolefin manufacturing employs highly efficient catalysts in the absence of organic solvents, and the products are readily tunable to meet a wide range of packaging challenges. Polyolefins represent a very economically viable packaging solution, arguably the most affordable family of available plastic packaging options. One shortcoming of polyolefin packaging is its lack of barrier performance for carbon dioxide and oxygen, and consequently innovation continues to address this limitation. Multilayered packaging has provided immense opportunity over the past two decades, particularly focused on the inclusion of a barrier layer to impart exceptional resistance to oxygen ingress. Multilayered packaging (recycling code 7) presents challenges to the recycling industry, demanding innovation in separation technologies. For example, the common disposable coffee packages that are easily inserted into countertop coffee machines are not readily recycled. Traditional multilayered coffee packaging potentially consists of PS, polyolefins, and a high-barrier poly(vinyl alcohol) central layer. In addition, tie layers ensure mechanical durability and adhesion between dissimilar layers. Multicomponent packages with a recycling strategy represent an exciting opportunity to maximize performance and increase the availability of other foods. Manufacturing of many consumer packages continues to employ subtractive processes. For example, thermoforming remains a common example of a process where a prefabricated mold shapes a softened polymer film. The final package or container is subsequently subtracted from the residual film precursor. Thermoforming typically results in high percentages of film waste, often termed “scrap.” Additive manufacturing leads to less waste and opportunities to fabricate complex packages with a synergy of novel materials, unique geometries, and easily embedded quality sensors.4Williams C.B. Mistree F. Rosen D.W. J. Mech. Des. 2011; 113: 121002-121012Crossref Scopus (70) Google Scholar We waste nearly 40% of our food;5Gunders D. NRDC Issue Paper, Wasted: How America Is Losing Up to 40 Percent of Its Food from Farm to Fork to Landfill (Natural Resources Defense Council).https://www.nrdc.org/sites/default/files/wasted-food-IP.pdfDate: 2012Google Scholar intelligent polyester packaging with embedded sensors could provide consumers with an indication of freshness and a real-time inventory as they shop at the grocery store. Innovation in plastic packaging lies at the intersection of material discovery and advanced manufacturing in partnership with architects who design the kitchens and bathrooms of the future. However, legacy manufacturing operations, including injection molding, extrusion, and blow molding, define the seven recycling codes; additive manufacturing will demand novel polymer design and hence require more from the recycling community. “Benign by design” will continue to challenge the ambiguity of recycling code 7 by giving attention to the design of reversible polymers, cost-effective renewable feedstocks, smart containers for real-time feedback, new multicomponent packages made by additive manufacturing, and programs to encourage consumer attention to recycling. Now is the time to implement a “molecules-to-manufacturing” approach to innovative packaging for the future. Reaction: Polymer Chemistries Enabling Cradle-to-Cradle Life Cycles for PlasticsHelms et al.ChemDecember 08, 2016In BriefBrett A. Helms is a San Francisco Bay Area native. He received his BS from Harvey Mudd College in 2000 and his PhD in 2006 in macromolecular design at the University of California, Berkeley, with Jean M.J. Fréchet. His postdoctoral research was conducted at the Technische Universiteit Eindhoven with E.W. Meijer, and his focus was on supramolecular chemistry. In 2007, he began his independent career at Lawrence Berkeley National Lab. Thomas P. Russell is the Silvio O. Conte Distinguished Professor in the Polymer Science and Engineering Department at the University of Massachusetts Amherst, visiting professor at the Lawrence Berkeley National Laboratory, PI of the WPI Advanced Institute of Materials Research at Tohoku University, and adjunct professor at the Beijing University of Chemical Technology. He is an elected member of the US National Academy of Engineering (2008). He received his PhD in polymer science and engineering from University of Massachusetts Amherst in 1979. Full-Text PDF Open ArchiveCatalyst: Design Challenges for the Future of Plastics RecyclingJeannette M. GarcíaChemDecember 08, 2016In BriefDr. Jeannette García is a chemist at IBM Research–Almaden. Her research focuses on the rational design of new polymers and materials through sustainable methods and targeting recyclable materials with previously inaccessible properties. García received her PhD in chemistry at Boston College in 2012 under the guidance of Dr. Amir H. Hoveyda and worked with Dr. Jim Hedrick as a postdoctoral researcher until 2013. García is one of MIT Tech Review’s 35 Innovators Under 35 for 2015, Business Insider’s 17 IBM Research Rock Stars, and the recipient of the World Technology Individual Award in Materials. Full-Text PDF Open ArchiveReaction: Design with the End in MindStefan J. PastineChemDecember 08, 2016In BriefStefan J. Pastine is an entrepreneur and scientist with diverse chemical research experience in complex organic synthesis, polymer chemistry, organic materials science, biomimicry, and nanotechnology. He founded Connora Technologies, a next-generation chemistry and materials company pioneering the concepts of recyclable thermoset technology (Recyclemine) for composite applications and thin, high-performance dielectrics (CSD technology) for mobile electronics. He received his PhD in organic chemistry from Columbia University and was awarded an NIH Postdoctoral Fellowship to study organic materials science at the University of California, Berkeley. He is a recipient of the 2010 R&D100 and the 2012 American Composite Manufacturing Association BEST awards. Full-Text PDF Open Archive
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