Stimuli responsive materials Theato, Patrick; Sumerlin, Brent S; O'Reilly, Rachel K ...
Chemical Society reviews,
2013-Sep-07, Volume:
42, Issue:
17
Journal Article
Peer reviewed
Guest editors Patrick Theato, Brent Sumerlin, Rachel O'Reilly and Thomas Epps, III introduce the Stimuli responsive materials themed issue of
Chemical Society Reviews
.
Block polymers (BPs) derived from biomass (biobased) are necessary components of a sustainable future that relies minimally on petroleum-based plastics for applications ranging from thermoplastic ...elastomers and pressure-sensitive adhesives to blend compatibilizers. To facilitate their adoption, renewable BPs must be affordable, durable, processable, versatile, and reasonably benign. Their desirability further depends on the relative sustainability of the renewable resources and the methods employed in the monomer and polymer syntheses. Various strategies allow these BPs' characteristics to be tuned and enhanced for commercial applications, and many of these techniques also can be applied to manipulate the wide-ranging mechanical and thermal properties of biobased and self-assembling block polymers. From feedstock to application, this review article highlights promising renewable BPs, plus their material and assembly properties, in support of
de novo
design strategies that could revolutionize material sustainability.
In supporting sustainability needs, this review article highlights renewable block polymers and their material characteristics, from feedstock to application opportunities.
In this perspective, we survey recent advances in the synthesis and characterization of block copolymers, discuss several key materials opportunities enabled by block copolymers, and highlight some ...of the challenges that currently limit further realization of block copolymers in promising nanoscale applications. One significant challenge, especially as the complexity and functionality of designer macromolecules increases, is the requirement of multiple complementary techniques to fully characterize the resultant polymers and nanoscale materials. Thus, we highlight select characterization and theoretical methods and discuss how future advances can improve understanding of block copolymer systems. In particular, we consider the application of theoretical/simulation methods to the rationalization, and prediction, of observed experimental self-assembly phenomena. Finally, we explore several next steps for the field and emphasize some general areas of emerging research that could unlock additional opportunities for nanostructure-forming block copolymers in functional materials.
In this perspective, we survey recent advances in the synthesis and characterization of block copolymers, discuss several key materials opportunities enabled by block copolymers, and highlight some of the challenges that currently limit further realization of block copolymers in promising nanoscale applications.
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Plastics have revolutionized modern life, but have created a global waste crisis driven by our reliance and demand for low-cost, disposable materials. New approaches are vital to address challenges ...related to plastics waste heterogeneity, along with the property reductions induced by mechanical recycling. Chemical recycling and upcycling of polymers may enable circularity through separation strategies, chemistries that promote closed-loop recycling inherent to macromolecular design, and transformative processes that shift the life-cycle landscape. Polymer upcycling schemes may enable lower-energy pathways and minimal environmental impacts compared with traditional mechanical and chemical recycling. The emergence of industrial adoption of recycling and upcycling approaches is encouraging, solidifying the critical role for these strategies in addressing the fate of plastics and driving advances in next-generation materials design.
Sustainable polymers from lignocellulosic biomass have the potential to reduce the environmental impact of commercial plastics while also offering significant performance and cost benefits relative ...to petrochemical-derived macromolecules. However, most currently available biobased polymers are hampered by insufficient thermomechanical properties, low economic feasibility (e.g., high relative cost), and reduced scalability in comparison to petroleum-based incumbents. Future biobased materials must overcome these limitations to be competitive in the marketplace. Additionally, sustainability challenges at the beginning and end of the polymer lifecycle need to be addressed using green chemistry practices and improved end-of-life waste management strategies. This viewpoint provides an overview of recent developments that can mitigate many concerns with present materials and discusses key aspects of next-generation, biobased polymers derived from lignocellulosic biomass.
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7.
Block Copolymer Vitrimers Lessard, Jacob J; Scheutz, Georg M; Sung, Seung Hyun ...
Journal of the American Chemical Society,
01/2020, Volume:
142, Issue:
1
Journal Article
Peer reviewed
In this report, we merge block copolymers with vitrimers in an effort to realize the prospect of higher-order, nanoscale control over associative cross-link exchange and flow. We show the use of ...controlled polymerization as a vital tool to understand fundamental structure–property effects through the precise control of polymer architecture and molecular weight. Vitrimers derived from self-assembling block copolymers exhibit superior resistance to macroscopic deformation in comparison to their analogs generated from statistical copolymers. Our results suggest that the enhanced creep resistance achieved by control over chain topology in block vitrimers can be used to tune viscoelastic properties. The resistance to macroscopic deformation that arises from a microphase-separated structure in this new class of materials differentiates block vitrimers from their statistical counterparts and introduces the potential of topology-control over viscoelastic flow.
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We report a new and robust strategy toward the development of high-performance pressure sensitive adhesives (PSAs) from chemicals directly obtained from raw biomass deconstruction. A particularly ...unique and translatable aspect of this work was the use of a monomer obtained from real biomass, as opposed to a model compound or lignin-mimic, to generate well-defined and nanostructure-forming polymers. Herein, poplar wood depolymerization followed by minimal purification steps (filtration and extraction) produced two aromatic compounds, 4-propylsyringol and 4-propylguaiacol, with high purity and yield. Efficient functionalization of those aromatic compounds with either acrylate or methacrylate groups generated monomers that could be easily polymerized by a scalable reversible addition–fragmentation chain-transfer (RAFT) process to yield polymeric materials with high glass transition temperatures and robust thermal stabilities, especially relative to other potentially biobased alternatives. These lignin-derived compounds were used as a major component in low-dispersity triblock polymers composed of 4-propylsyringyl acrylate and n-butyl acrylate (also can be biobased). The resulting PSAs exhibited excellent adhesion to stainless steel without the addition of any tackifier or plasticizer. The 180° peel forces were up to 4 N cm–1, and tack forces were up to 2.5 N cm–1, competitive with commercial Fisherbrand labeling tape and Scotch Magic tape, demonstrating the practical significance of our biomass-derived materials.
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Stimuli-responsive polymeric materials is one of the fastest growing fields of the 21st century, with the annual number of papers published more than quadrupling in the last ten years. The ...responsiveness of polymer solution assemblies and surfaces to biological stimuli (
e.g.
pH, reduction-oxidation, enzymes, glucose) and externally applied triggers (
e.g.
temperature, light, solvent quality) shows particular promise for various biomedical applications including drug delivery, tissue engineering, medical diagnostics, and bioseparations. Furthermore, the integration of copolymer architectures into stimuli-responsive materials design enables exquisite control over the locations of responsive sites within self-assembled nanostructures. The combination of new synthesis techniques and well-defined copolymer self-assembly has facilitated substantial developments in stimuli-responsive materials in recent years. In this tutorial review, we discuss several methods that have been employed to synthesize self-assembling and stimuli-responsive copolymers for biomedical applications, and we identify common themes in the response mechanisms among the targeted stimuli. Additionally, we highlight parallels between the chemistries used for generating solution assemblies and those employed for creating copolymer surfaces.
This tutorial review highlights key advances in the synthesis and self-assembly of stimuli-responsive copolymers for biomedical applications.
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