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2023 Polymer Chemistry Lectureship awarded to Professor Miao Hong

We are delighted to announce Professor Miao Hong (Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences) as the recipient of the 2023 Polymer Chemistry lectureship.

 

This award, now in its ninth year, honours an early-career researcher who has made significant contribution to the polymer field. The recipient is selected by the Polymer Chemistry Editorial Board from a list of candidates nominated by the community.

 

Profile picture of Professor Miao Hong  

 

 ‘What impressed me most about Polymer Chemistry is that the manuscripts are being professionally handled with high efficiency.’

 

 

Miao Hong received her Ph.D. degree in 2013 under the supervision of Professor Yuesheng Li from the Changchun Institute of Applied Chemistry, Chinese Academy of Sciences. After a four-year postdoctoral stint at Colorado State University with Professor Eugene Y.-X. Chen, she joined Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences in 2017 as a Full Professor of Chemistry. Research in the Hong group is centred on polymer science, catalytic chemistry, green and sustainable chemistry, and with one of the main interests being the development of novel catalysts and new methodologies for the production of sustainable polymers with controlled structures from renewable feedstocks.

 

To learn more about Professor Hong’s research, have a look at her most recent publication in Polymer ChemistryInsights into the interaction between bis(aryloxide)alkylaluminium and N-heterocyclic carbene: from an abnormal Lewis adduct to a frustrated Lewis pair for efficient polymerizations of biomass-derived acrylic monomers

This is free to access until 30th September 2023, and featured in our most recent Pioneering Investigators collection. You can also check out articles from our previous lectureship winners in our lectureship winners collection.

 

Read our interview with Professor Hong below:

 

How has your research evolved from your first article to you most recent article?

The research in my group is centered on the development of novel catalysts and new methodologies for the production of sustainable polymers with controlled structures from renewable feedstocks. One of major challenges encountered in this area is the conventional catalytic systems, which can effectively polymerize petrochemical monomers, are generally inert/sluggish or uncontrolled toward the polymerization of biomass-derived monomers due to their unique heteroatom-rich structure natures. Take β-angelica lactone as an example, a key downstream chemical of levulinic acid which is available in a total yield of more than 80% from cellulose and classified as one of top biomass-derived compounds best suited to replace petroleum-derived chemicals. However, its polymerization is inaccessible by traditional polymerization methods, such as group transfer, coordination-addition, and radical polymerizations.

 

The first “real” article in my group, accomplished by my first Ph.D. student, is the achievement of the first polymerization of β-angelica lactone through developing a new cooperative Lewis pair catalyst. Accordingly, a heat- and solvent-resistant acrylic bioplastic is effectively synthesized. This work was published in Angew. Chem. Int. Ed. (2020, 59, 2664) and designed as a Hot Paper. On the basis of this work, we further optimized the catalyst structure and established a new and stable Frustrated Lewis pair in our very recently work (Polym. Chem. 2023, 14, 3286 – 3293), which is not only efficient for β-angelica lactone polymerization, but also can mediate fast and controlled polymerizations of methyl crotonate and (E,E)-methyl sorbate, thus establishing a general catalyst for the polymerizations of inert biomass-derived acrylic monomers. Overall, the striking findings from our group and the other groups (e.g. Chen, Zhang, Takasu) shed light on the great potential of cooperative Lewis pair catalysts for efficient polymerizations of challenging biomass-derived monomers.

 

What excites you most about your area of research and what has been the most exciting moment of your career so far?

The most exciting moment of my research career so far should be the successful chemical synthesis of high-molecular-weight biomaterial poly(4-hydroxybutyrate) for the first time via ring-opening polymerization (ROP) of γ-butyrolactone (Nat. Chem. 2016, 8, 42), a biomass-derived lactone monomer commonly referred as “non-polymerizable” in the textbooks and literatures due to low ring strain energy, when I was a Postdoc in Prof. Eugene Y.-X. Chen’ group at Colorado State University. However, such ROP requires extremely low reaction temperature, which severely hampers the possibly industrial applicability of the resultant polymer.

 

Recently, my group established a new polymerization strategy, termed isomerization-driven ROP (iROP). Different from conventionally ring strain-driven ROP, such polymerization is thermodynamically driven by S/O isomerization, thus rendering non-strained five-membered rings highly polymerizable for the first time at industrially relevant temperature of 80-100 °C. I am quite excited about iROP, because it is a simple and powerful strategy which not only can circumvent the unfavorable thermodynamics of ROPs of ‘non-stained’ five-membered lactones, and also presents a fascinating opportunity to convert these abundant, but underexploited renewable feedstocks (e.g. γ-butyrolactone, γ-valerolactone, peach lactone, dihydrojasmone lactone, whiskey lactone) into new sustainable polymers with their key physical properties comparing well to representative commodity polyolefin plastics (Nat. Chem. 2022, 14, 294; Angew. Chem. Int. Ed. 2023, 62, e202217812).

 

In your opinion, what are the most important questions to be asked/answered in your field of research?

One of the most important questions in the field of sustainable polymers should be how to reshape the current petroleum-based polymer industry with sustainable polymers.  That is how to bring the beautiful synthetic schemes and intriguing physical properties of sustainable polymers developed in academia into industrial processes and cost-effective polymeric products. To address this question, cross-disciplinary research (such as polymer chemistry, physics, processing, engineering, and even information technology and artificial intelligence) is highly desirable, and the collaboration between both polymer industry and academic researchers is also essential.

 

How do you feel about Polymer Chemistry as a place to publish research on this topic?

What impressed me most about Polymer Chemistry is that the manuscripts are being professionally handled with high efficiency. Take our recent research article published by Polymer Chemistry as an example. The manuscript was submitted on 17th May 2023, the peer review of which only took two weeks, and accepted fast on13th June 2023.

 

In which upcoming conferences or events (online or in person) may our readers meet you?

The conferences on my schedule are the National Polymer Academic Paper Conference (Oct. 13-17, 2023, Wuhan, China) and IUPAC MACRO 2024 (July 1-4, 2024, Warwick University, United Kingdom).

 

Can you share one piece of career-related advice or wisdom with early career scientists?

You always can find ideas/answers in the literatures when you face the scientific questions.

 

How do you spend your spare time?

Try my best to accompany my family in my spare time. I always feel frustrated to balance work and life.

 

We would like to thank everybody who nominated a candidate for the 2023 Polymer Chemistry Lectureship. The Editorial Board had a very difficult task in choosing a winner from the many excellent and worthy candidates.

 

Please join us in congratulating Professor Hong on winning this award!

 

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Emerging Investigator Series – James Eagan

James M. Eagan is an assistant professor at the University of Akron School of Polymer Science and Polymer Engineering. His research focuses on improving the performance of recycled polymer blends and in the development of new polymers derived from sustainable feedstocks, such as olefins and carbon dioxide. In the community, he and his group promote sustainable polymer solutions through the Akron Polymer Industry Cluster, and sponsor research experiences for young scientists through the ACS Seed program, and Ohio Department of Education. He received his Ph.D. from Columbia University in 2014 under the guidance of Scott A. Snyder and completed postdoctoral studies at Cornell University under Geoffrey W. Coates. He is the recipient of the AAAS Newcomb Cleveland Prize, NSF Faculty Early Career Development award, and the ACS Petroleum Research Foundation (PRF) New Investigator Grant.

Read James’s Emerging Investigator Paper, Ethylene polymerization using heterogeneous multinuclear nickel catalysts supported by a crosslinked alpha diimine ligand network, DOI: D3PY00118K.

 

Check out our interview with James below:

 

What aspect of your work are you most excited about at the moment and what do you find most challenging about your research?

We investigate new polymerization catalysts and methods, and the most exciting aspect in this area is the discovery of new materials from old feedstocks.  It is incredible that after more than a century of research into simple monomers like ethylene, propene, and butadiene, novel macromolecules and material properties can still be discovered.  The most challenging part of our research is connecting the performance of new polymers to sustainable applications and ensuring that renewable alternatives meet, or surpass, existing material properties.

 

Find out more about James’s research on the Eagan Lab Group Page.

 

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Paper of the Month: Geared photochemistry: an interdependent heterogeneous near-infrared catalytic system using up-conversion glass and g-CN for CuAAC chemistry

Kocaarslan et al. employ a heterogeneous near-infrared catalytic system using up-conversion glass (UCG) and g-CN to synthesize (macro)molecules via click chemistry.

 

 

The efficiency and accessibility of “click” chemistry, and more specifically the copper-catalyzed azide-alkyne cycloaddition reaction (CuAAC), have been valorized in synthetic macromolecular chemistry via a plethora of approaches. In this synthetic arena, photochemical process have been shown to efficiently achieve the in situ reduction of air-stable copper(II) species to the active copper(I) species catalyzing CuAAC.

Expanding the scope of current CuAAC photocatalysis, Yagci and coworkers developed a “geared photochemistry” approach for NIR induced CuAAC click chemistry using a dual-heterogeneous photocatalyst that generates light emission in upconversion materials combined with graphitic carbon nitride (g-CN). To achieve this, it is shown that Tm3+ and Yb3+ ion-doped zinc-tellurite glass that absorbs laser irradiation at 975 nm and is capable of emitting blue light at 475 nm, can photocatalytically activate g-CN via an internal light emitting process. For the CuAAC process, this visible light excitation of g-CN in the presence of CuCl2/PMDETA was proven to generate active copper(Ι) species able to catalyze a CuAAC click reaction between various azide and alkyne compounds. This system was proven efficient in click reactions between macromolecular chains such as azide functional polystyrene (PS-N3) and alkyne functional poly(ε-caprolactone) (PCL-alkyne) yielding block copolymers with structurally different segments. In the same vein, photoinduced crosslinking could also be achieved upon irradiation of multifunctional click components (such as bisphenol A di(3-azido-2-hydroxy propan-1-ol) ether and 1-(prop-2-yn-1-yloxy)-2,2-bis((prop-2-yn-1yloxy)methyl) butane) with a 875 nm laser in the presence of mesoporous graphitic carbon nitride (mpg-CN) and CuCl2/PMDETA under open air conditions within 2 hours. Importantly, the heterogeneous catalyst prepared via the combination of graphitic carbon and UCG could be successfully used several times enhancing the applicability of the system.

The interdependent heterogeneous system using UCG in conjunction with g-CN under NIR light presented in this study, offers a highly efficient click methodology for (macro)molecules in synthetic (polymer) chemistry.

 

Tips/comments directly from the authors:

  • Our group’s research activities focus on the development of new photoinitiating systems for macromolecular synthesis. In this line, many photoinitiators acting at wide wavelength range of the electromagnetic spectrum were developed. “Geared photochemistry”, introduced for the first time in this paper, reflects the light-triggered reaction sequence that interdependently proceeds .  In this approach, up-conversion glass absorbs light at NIR region and convert it to visible light. Upon absorption of the emitted visible light graphitic carbon nitride (mpg-CN) in the reaction media creates electron and hole pairs. The copper (II) complex, which has no absorbance at these two wavelengths, is reduced from copper II to copper I by the released electrons. After all this gear-like system, copper I ions catalyze the click reaction between azide and alkyne compounds to form a triazole ring. We are happy to publish this work in an important journal in polymer science, Polymer Chemistry.
  • This approach will open new horizons not only for click chemistry, but also for many synthesis procedures involving electron transfer reactions. It should be considered that the change of absorbance with upconversion glasses is important for many light-activated photocatalysts.

 

Citation to the paper: Geared photochemistry: an interdependent heterogeneous near-infrared catalytic system using up-conversion glass and g-CN for CuAAC chemistry, Polym. Chem., 2022,13, 6393-6399, DOI: 10.1039/D2PY01075E

 

Link to the paper:

https://pubs.rsc.org/en/content/articlelanding/2022/py/d2py01075e

 

Kelly Velonia is saddened to hear about the passing of Prof. Yusuf Yagci, an exceptional scientist and person. Condolences to his family and loved ones. The polymer community will certainly miss him.

 

 

Dr. Kelly Velonia is an Advisory Board Member and a Web Writer for Polymer Chemistry. She joined the Department of Materials Science and Technology at the University of Crete in 2007. Research in her group focuses on the synthesis and applications of bioconjugates and biopolymers. You can follow Kelly on twitter @KellyVelonia


 

 

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Polymer Chemistry Overview of 2022

Now that 2022 has come to an end, join us as we look back at some of the highlights of last year and forward to our upcoming activities in 2023!

 

Polymer Chemistry Top Picks of 2022

We have selected some of the most cited, most downloaded and most shared articles published in Polymer Chemistry from the last year for our Most Popular 2022 collection.

All articles in this collection are FREE to read until 28 February 2023.

Congratulations to all featured authors!

 

Editorial Board

We would like to thank Professor Wei You for his support of Polymer Chemistry as he stepped down from his role on the Editorial Board at the end of 2022.

 

Polymer Chemistry Lectureship

The Polymer Chemistry Lectureship 2022 was awarded to Professor Dominik Konkolewicz (Miami University, USA). This annual award was established in 2015 to honour an early-stage career scientist who has made a significant contribution to the polymer field. The Konkolewicz group explores a range of topics in polymer chemistry, including radical polymerisation mechanisms, dynamically bonded polymer materials, light driven reactions, bioconjugates and polymer based self-assembly. Find out more about Dominik and his research on our Lectureship winner blog post. You can check out articles from Dominik and our previous winners in the Lectureship winners collection.

Profile picture of Dominik Konkolewicz

Did you know that nominations for the Polymer Chemistry Lectureship 2023 are now open? If you know an outstanding early career researcher in polymers, nominate them before the 28 February 2023.

Full details about eligibility and the nominations process can be found here

Polymer Chemistry Emerging Investigators

Polymer Chemistry is proud to spotlight our ongoing Emerging Investigators Series. Our Emerging Investigators are at the early stages of their independent careers and invited for this collection in recognition of their potential to influence future directions in the field. Congratulations to all the featured researchers on their important work so far!

Read the collection

Meet the Scientists

 

Themed collections

Polymer Chemistry is delighted to have featured some of your best work in our themed collections in 2022.

We promoted themed collections on ‘Molecularly defined polymers: synthesis and function’ Guest Edited by Jeremiah Johnson, Filip Du Prez and Elizabeth Elacqua, ‘Sustainable Polymers’ Guest Edited by Antoine Buchard and Tanja Junkers,  ‘Photopolymer science’ dedicated to Prof. Ewa Andrzejewska and ‘Synthetic Methodologies for Complex Macromolecular Structures in honour of Prof. Yusuf Yagci’s 70th birthday

Check out some of these ongoing collections:

 

Browse all past collections on our platform and see our upcoming collections on our calls for submissions page. We will be announcing more collections during the year, so keep a look out!

 

HOT articles

Remember to check out our ongoing Polymer Chemistry HOT articles collection featuring articles highlighted by our Editors and referees. All articles in the collection are FREE to read until 28 February 2023.

 

 

Paper of the Month blogs

Our Web Writer and Advisory Board member Dr Kelly Velonia publishes a blog highlighting an interesting publication of her choice each month. She summarises the work and interviews the authors for tips and comments about their work.

Check out the ‘Paper of the Month’ blogs for 2022 here

 

Open Access

The Royal Society of Chemistry has announced that all 31 fully-owned hybrid journals, including Polymer Chemistry, have been approved as “Transformative Journals” with cOAlition S, an international consortium of research funding and performing organisations. Find out more about our strive towards 100% Open Access here.

 

#RSCPoster: Save the date

#RSCPoster is a global Twitter Poster Conference, held entirely online over the course of 24 hours. The event brings together the global chemistry community to network with colleagues across the world and at every career stage, share their research and engage in scientific debate.

The 2023 #RSCPoster Twitter Conference will be held from 12:00 (UTC) 28 February 2023 to 12:00 (UTC) 1 March 2023.

How you can help…

We would like to take this opportunity to thank all of you in addition to our authors, reviewers and readers for their support throughout 2022. Here are some of the ways in which you can continue to make a positive contribution to Polymer Chemistry:

Submit to one of our open themed collections and encourage your colleagues to submit.

If you are organising a conference or virtual event, please do let us know if you would like to arrange mutual promotion between the conference and Polymer Chemistry. We can offer poster prizes, social media and blog promotion, and adverts in the journal and on the journal web page.

Read our recent articles and follow the latest news on the Polymer Chemistry blog and on our Facebook and Twitter pages.

Send your best research to Polymer Chemistry.

Sign up to be a reviewer for Polymer Chemistry.

 

Thank you for your continued interest in and support of Polymer Chemistry. We look forward to seeing what 2023 brings!

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Polymer Chemistry Emerging Investigator- Guoming Liu

Guoming Liu received his Ph.D. from the Institute of Chemistry, Chinese Academy of Sciences (ICCAS) (2011). Since then, he has been working at ICCAS, where he is currently Professor. From 2016 to 2018, he was a postdoctoral researcher at Cavendish Laboratory, University of Cambridge, as a Newton International Fellow of the Royal Society. His research interests include structure-property relationships of polymers, polymer crystallization and relaxation in confined space, and structure characterization by X-ray and neutron scattering.

 

Read Guoming’s Emerging Investigator article, ‘Achieving High Elasticity of Trans-1, 4-Polyisoprene with a Combination of Radiation Crosslinking and Thiol-ene Grafting’, DOI: 10.1039/D2PY01218A

 

Check out our interview with Guoming below:

1. How do you feel about Polymer Chemistry as a place to publish research on this topic?

Polymer Chemistry is one of the top journals in polymer science with a focus on polymer synthesis and applications of polymers. It has established high criteria for paper quality and a good reputation among authors and readers. I definitely would like to publish my next research paper in Polymer Chemistry.

2. In your opinion, what are the most important questions to be asked/answered in this field of research?

One of the most important questions is how to develop sustainable polymer materials economically. This may require new monomers from renewable resources, new chemistry for polymerization/depolymerization, and new processing technologies.

3. Can you share one piece of career-related advice or wisdom with other early career scientists?

It is important to establish unique expertise in the field, either by setting up new tools or developing new methods or technologies.

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Paper of the month: Ring opening polymerization of ε-caprolactone through water

Atta et al. demonstrates a simplified ROP protocol which operates in the absence of any inert gas and without the need of drying any of the reaction’s reagents.

image describing the work

Ring Opening Polymerization (ROP) is arguably one of the most popular methodologies to synthesize biodegradable materials such as polycaprolactone (PCL) and poly (lactic acid) (PLA). However, a major drawback of this approach which severely limits its applicability is that it typically operates under completely moisture-free conditions, as water is well-known to deactivate the catalyst and terminate the propagating chains. To avoid water contamination, highly specialized equipment (e.g., Schlenk lines or glove boxes) as well as anhydrous reagents have to be employed which makes the process particularly tedious for both experts and non-experts. To overcome this, Gormley and co-workers have developed two elegant and simple methods that allow for the facile synthesis of PCL through ROP in a laboratory oven and without using any inert gas or dry reagents. In the first technique, a vacuum oven was employed to evaporate water from a traditional ROP reaction with stannous octoate as the catalyst while in the second approach titanium isopropoxide was utilized to simultaneously quench residual water and catalyze ROP. Impressively, and despite the simplicity of those methodologies, a range of chain lengths could be synthesized (degree of polymerization 25-500) with relatively good control over the molecular weight distributions of PCL (Đ < 1.5 for all cases). It is highlighted that a large excess of water impurities (750 ppm) could be tolerated by both methods yielding well-defined polymers at quantitative conversions. This work represents a great example of a simplified ROP which operates in the absence of complicated reactions set ups and can be performed in any laboratory. As the authors also remark, targeting even higher molecular weights or achieving even lower dispersity values will be the next challenge to address and we very much look forward to the next developments by the Gormley group.

Tips/comments directly from the authors:

  • The rational goal of this work is to enable the ROP reaction in an oven without inert gas environment and without drying or purifying the reagents.
  • The most exciting aspect of this work is to enable non-experts to synthesize custom polymers.
  • TTIP plays multiple roles in this ROP reaction. It not only initiates and catalyzes the polymerization reaction but also eliminates water from the reaction medium.
  • It is important for the audience that we should perform this experiment with minimal mixing time (within 1-5 sec) as water present in the air can contaminate CL.
  • The purity of CL can be easily checked by TTIP. A precipitate of TiO2 was formed when the water content of CL was above 750 ppm, and a cloudy solution was observed.

Citation to the paper: Ring opening polymerization of ε-caprolactone through water, Polym. Chem., 2021,12, 159-164, DOI: 10.1039/D0PY01481H

Link to the paper: https://pubs.rsc.org/en/content/articlepdf/2021/py/d0py01481h 

Professor Athina AnastasakiDr. Athina Anastasaki is an Editorial Board Member and a Web Writer for Polymer Chemistry. Since January 2019, she joined the Materials Department of ETH Zurich as an Assistant Professor to establish her independent research group.

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Paper of the month: Enzyme-responsive polymeric micelles with fluorescence fabricated through aggregation-induced copolymer self-assembly for anticancer drug delivery

Yan et al. develop new enzyme-responsive polymeric micelles with potential applications in cancer therapy.

image describing the work

One of the most exciting and fast-growing topics in polymer chemistry is the synthesis of amphiphilic copolymers that can self-assemble into nanoparticles. Hydrophobic compounds such as cancer drugs can be encapsulated in the core of these self-assembled nanoparticles, thus protecting them from degradation or unwanted interactions with healthy cells. In addition, advances in polymer end-group functionalization allow the conjugation of special ligands on the nanoparticle surface which are responsible for directing the nanoparticles to cancer cells. Upon reaching the tumours (or being taken up by cancer cells), the nanoparticles must release the encapsulated drugs in order to kill the cancer cells. This drug release step requires the use of stimuli-responsive smart polymers that can switch from hydrophobic to hydrophilic upon exposure to stimuli. Temperature, pH, and enzyme-responsive polymers are therefore developed to release drugs on-demand. In this work, Zhao and co-workers further advance the field by synthesizing new fluorescent nanoparticles which can release a cancer drug (doxorubicin) while simultaneously turning off the fluorescent signal when the drug is released. This was achieved by efficiently coupling a tetraphenylethene moiety onto poly(acrylic acid). The hydrophobic property of the tetraphenylethene moiety induces the self-assembly of the resulting diblock copolymers into fluorescent nanoparticles via an aggregation-induced self-assembly mechanism. Upon exposure of the fluorescent nanoparticles to esterase, this enzyme can hydrolyze the ester bond between the tetraphenylethene side chain and the polymer backbone. The enzyme-catalyzed hydrolysis reaction turns the hydrophobic block back to the water-soluble poly(acrylic acid) block and therefore, disassembles the nanoparticles and also turns the fluorescent signal off. The diblock copolymer has poly(ethylene glycol) as the corona-forming block which possesses negligible toxicity to healthy cells. Therefore, this new copolymer is very promising for drug delivery applications, especially when monitoring the drug release is essential.

Citation to the paper: Visible light enabled para-fluoro-thiol ligation, Polym. Chem., 2020, 11, 7704-7713, DOI: 10.1039/D0PY01328E

Link to the paper: https://pubs.rsc.org/en/content/articlepdf/2020/py/d0py01328e

Professor Athina Anastasaki Dr. Athina Anastasaki is an Editorial Board Member and a Web Writer for Polymer Chemistry. Since January 2019, she joined the Materials Department of ETH Zurich as an Assistant Professor to establish her independent research group.

 

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Paper of the month: Direct laser writing of poly(phenylene vinylene) on poly(barrelene)

Bielawski and co-workers report the ROMP of barrelene monomer affording precisely defined fluorescent patterns with micrometer-sized dimensions.

 

 

Conjugated polymers have attracted considerable attention owing to their abilities to form films and exhibit high electrical conductivities and as such they have found use in a range of electronic and optical applications. Amongst the various types of polymers, poly(phenylene vinylene) (PPV) is an excellent candidate due to its low optical band gap, large nonlinear optical response, and emissive properties. However, this material is typically intractable and thus challenging to process. To overcome this, Bielawski and co-workers designed a new approach to PPV was through the ring-opening metathesis polymerization (ROMP) of “barrelene” (bicyclo[2.2.2]octa-2,5,7-triene). The monomer was characterized for the first time by X-ray diffraction analysis of a coordination complex. Barrelene was subsequently homopolymerized and copolymerized with norbornene. The solubility of barrelene homopolymers was found to depend on the cis to trans ratio of alkene in its backbone. Both the homo and copolymers were transformed to PPV by undergoing spontaneous dehydrogenation under air. The materials were analyzed by a range of spectroscopic techniques. Importantly, direct laser writing of the barrelene-containing copolymers was also demonstrated resulting in thermal aromatization within a few seconds affording precisely defined fluorescent patterns with micrometer-sized dimensions. An intrinsic advantage of this development is that the monomer can be potentially incorporated into different macromolecular scaffolds and at varying compositions. Owing to this unique characteristic, the authors envision that their designed strategy would enable the synthesis of a broad range of materials for use in laser machining and contemporary lithography applications.

 

Tips/comments directly from the authors:

 

1)  The solubility of poly(barrelene) is dependent on the cis-to-trans ratio of the exocyclic olefins in the polymer backbone. Polymers with relatively high cis olefin contents appear to be more soluble than their trans isomers.

2)  The resolution of the patterns created by direct laser writing appear to be inversely proportional to the barrelene content of the copolymer used and may be enhanced further by increasing the transparency of the films.

3)  Poly(barrelene) oxidizes in air (slow) or upon laser irradiation (fast). A convenient way to monitor the oxidation reaction is through fluorescence spectroscopy. The starting material is non-emissive whereas the poly(phenylene vinylene) product emits a fluorescent green color upon excitation.

4)  Because barrelene is strained, copolymerization with other monomers used in ring-opening metathesis polymerization methodologies can be expected which, in turn, may expand the utility of the direct laser writing technique.

 

Citation to the paper: Direct laser writing of poly(phenylene vinylene) on poly(barrelene), Polym. Chem., 2020, 11, 5437-5443, DOI: 10.1039/d0py00869a

 

Link to the paper:

https://pubs.rsc.org/en/content/articlepdf/2020/py/d0py00869a

Professor Athina AnastasakiDr. Athina Anastasaki is an Editorial Board Member and a Web Writer for Polymer Chemistry. Since January 2019, she joined the Materials Department of ETH Zurich as an Assistant Professor to establish her independent research group.

 

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Paper of the month: Single-chain crosslinked polymers via the transesterification of folded polymers: from efficient synthesis to crystallinity control

Terashima and co-workers report efficient synthetic systems of single-chain crosslinked polymers.

 

Crosslinked polymers have emerged as a class of unique materials which find use in a diverse range of applications such as drug delivery, dispersants and coating industries. Typically, those materials are made through a combination of controlled polymerization and crosslinked methods. In this work, Terashima and co-workers prepared a range of single-chain crosslinked polymers with controlled crystallization. This was achieved by the intramolecular transesterification of random copolymers compromising of octadecyl methacrylate, 2-hydroxyethyl methacrylate, and methyl acrylate. Those copolymers were self-folded in organic media (octane was used as the solvent) through the association of the hydroxyl groups to form reverse micelles. Upon synthesis, the micelles were intramolecularly crosslinked by an efficient transesterification of the methyl acrylate units with the hydroxyl groups to produce polymer nanoparticles with pending octadecyl groups. The materials synthesized were thoroughly characterized by a number of techniques including nuclear magnetic resonance, gel permeation chromatography, small angle X-ray scattering and dynamic light scattering. The developed system allowed for the efficient control of the molecular weight of the crosslinked polymers owing to the precise synthesis of the precursors prepared by living radical polymerization. Importantly, the degree of crosslinking was found to control the crystallinity of the products. Last but not least, a relatively high concentration could be used (up to 50 mg ml-1).  As the authors allude to in their conclusion, their work has paved the way to the production of well-defined polymeric nanoparticles that can be employed for surface coating, painting, optical plastics and cosmetics.

 

Tips/comments directly from the authors:

 

1) Intramolecular crosslinking of folded polymers in organic media via transesterification affords the precision and high-throughput synthesis of single-chain crosslinked polymer nanoparticles.

2) The molecular weight of the crosslinked polymers can be controlled as desired at the stage of the synthesis of the precursor polymers by controlled radical polymerization.

3) Transesterification between hydroxyl groups and methyl acrylate units efficiently proceeds within the cores of folded micelles to fix the folded structures in a specific solvent.

4) SEC-MALLS analysis is essential to characterize single-chain crosslinked polymers. Because of the compact structures, the apparent molecular weight of the crosslinked polymers by the general RI detector with PMMA standard calibration turns smaller than that of the non-crosslinked precursor polymers. If the absolute weight-average molecular weight of the crosslinked polymers by the MALLS detector is also close to that of the precursor polymers, you can conclude that the products consist of single chain-crosslinked polymers.

5) Crystallinity of the bulk polymers is controlled by tuning the degree of intramolecular crosslinking. This is an interesting approach to control the thermal and physical properties of solid polymer materials.

Citation to the paper: Single-chain crosslinked polymers via the transesterification of folded polymers: from efficient synthesis to crystallinity control, Polym. Chem., 2020, 11, 5181-5190, doi.org/10.1039/D0PY00758G

Link to the paper: https://pubs.rsc.org/en/content/articlepdf/2020/py/d0py00758g

About the web writer:

Professor Athina Anastasaki

Dr. Athina Anastasaki is an Editorial Board Member and a Web Writer for Polymer Chemistry. Since January 2019, she joined the Materials Department of ETH Zurich as an Assistant Professor to establish her independent research group.

 

 

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Spotlight on Rongrong Hu: 2018 Polymer Chemistry Emerging Investigator

This week’s issue of Polymer Chemistry is our 2020 Emerging Investigators issue, which contains articles from polymer chemistry researchers in the early stages of their independent careers and is accompanied by an Editorial from Editor-in-Chief Professor Christopher Barner-Kowollik. To celebrate this issue we are delighted to feature the profile of Professor Rongrong Hu, who published in our 2018 Emerging Investigators issue. Below, Rongrong talks about her research journey, from student to Professor, and her feelings towards Polymer Chemistry!

“With my organic synthesis training as an undergraduate student at Peking University where I learned the great diversity of organic reactions, and the research experiences on luminescent polymer materials during my PhD study at The Hong Kong University of Science and Technology where I learned the fascinating functionalities that polymers could achieve, I tried to combine organic synthesis and polymer synthesis in my research after I started my career in 2014. We utilize efficient organic reactions for the development of new polymerization methodology and the exploration of new polymer structures and materials. After 5 years of research, I am fully convinced by the huge opportunity that comes with this interdisciplinary study.

Polymer Chemistry, with its topics highly focused on the synthesis, functionalities, and applications of polymers, always provides timely publication and best publishing experiences on exciting progress in the field. It can also sensitively catch new research trend and young polymer chemists. In the 2018 Emerging Investigator issue, we introduced our work about room temperature alkyne and sulfonyl azide-based multicomponent polymerizations, which represent efficient approaches for the convenient construction of polymers with unique structures and functionalities. Encouraged by the broad response of this paper, we further developed several elemental sulfur-based multicomponent polymerizations with practical implication. Most recently, I joined Polymer Chemistry as an Associate Editor, working with the top polymer chemists in the world, to look for most up-to-date innovative and exciting polymer chemistry.”

 

Read Rongrong’s 2018 Emerging Investigators series paper below!

Room temperature multicomponent polymerizations of alkynes, sulfonyl azides, and N-protected isatins toward oxindole-containing poly(N-acylsulfonamide)s
Liguo Xu,   Fan Zhou,   Min Liao,   Rongrong Hu*  and  Ben Zhong Tang*
Polym. Chem., 2018,9, 1674-1683

FREE to read and download until the 1st March 2020.

Biography

Rongrong Hu received her B.S. degree from Peking University and her PhD degree from Hong Kong University of Science and Technology. She is currently a Professor of the State Key Laboratory of Luminescent Materials and Devices at South China University of Technology.

She has published over 110 peer-reviewed articles and reviews. Her research interests include (1) the development of alkyne or isocyanide-based multicomponent polymerization methodology through the combination of organic and polymer synthesis, and (2) luminescent polymers with diverse structures and applications. Her current research focuses on the development of multicomponent polymerizations of elemental sulfur and sulfur-containing functional polymers.

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