Archive for October, 2016

Paper of the month: Regioselective cross metathesis for block and heterotelechelic polymer synthesis

Radlauer et al. report the regioregularity of ring-opening metathesis polymerization and cross metathesis reactions for the synthesis of block and heterotelechelic materials.

Among the two distinct olefin metathesis polymerization methods, namely acyclic diene metathesis (ADMET) polymerization and ring opening metathesis polymerization (ROMP), ROMP possesses the advantage of proceeding by a chain growth mechanism and has been demonstrated to deliver polymers with an R substituent every 8 carbons from 3-substituted cyclooctene (3RCOE) monomers. Although secondary metathesis such as cross metathesis (CM) can occur between chains during ROMP, when the selectivity of 3RCOE monomers was examined, no studies on the CM were conducted. Towards this direction, Hillmyer and co-workers determined the CM of 3RCOE derivatives to be both regio- and stereoselective, making only a small fraction of t-TT and t-HH errors. As only a marginal increase in errors over time was observed, it was concluded that the system reached an equilibrium between the formation and fixing of errors. This stereo- and regioselectivity can be extended by combining polymers with different degrees of polymerization, or by combining polymers with different R substituents leading to the formation of multiblock or statistical copolymers depending on how long the CM is allowed to proceed. In the latter case, differential scanning calorimetry (DSC) confirms the transition from two Tgs to one Tg corresponding to a multiblock and a statistical copolymer, respectively. Additionally, the location of end groups from an asymmetric chain transfer agent can be controlled, thus allowing access to predominantly heterotelechelic oligomers or polymers despite the CM reactions that can occur between the chains.

Tips/comments directly from the authors:

  1. In our experience if a polymer turned brown, it was generally caused by the presence of deactivated Grubbs catalyst. To remove this contaminant at the end of the polymerization, the polymer was dissolved in chloroform and stirred with carbon black. Subsequent filtration and reprecipitation of the polymer generally yielded clear and colorless materials.
  2. To obtain SEC data that was more easily interpreted, we used adjusted ratios of the polymers of different degrees of polymerization in the polymer-polymer cross metathesis experiments. Though the 1:1 scenario still showed immediate CM to an average N, the resolution between the two peaks was quite poor.

Any experiment involving the acetal-containing chain transfer agent required that each reaction component be filtered over basic alumina to avoid deprotection of the acetal moiety.

Read this exciting research for free until 25/11/2016 through a registered RSC account:

Regioselective cross metathesis for block and heterotelechelic polymer synthesis
M.R. Radlauer, M.E. Matta and M.A. Hillmyer,
Polym. Chem., 2016, 7, 6269-6278,
DOI: 10.1039/C6PY01231K


About the webwriterAthina Anastasaki

Dr. Athina Anastasaki is a web writer for Polymer Chemistry. She is currently an Elings fellow working alongside Professor Craig Hawker at the University of California, Santa Barbara (UCSB). Please visit this website for more information.

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Lectureship winner featured on our back cover

We are immensely proud to share our back cover for Issue 40.

This beautiful image highlights research results by Professor Feihe Huang at University, Hangzhou, China. Professor Huang is the recipient of the 2016 Polymer Chemistry Lectureship award.

Pillar[5]arene-based amphiphilic supramolecular brush copolymers: fabrication,
controllable self-assembly and application in self-imaging targeted drug delivery

Guocan Yu, Feihe Huang, and co-workers fabricated the first pillar[5]arene-based amphiphilic supramolecular brush copolymer, which was utilized as a self-imaging drug delivery vehicle by taking advantage of the aggregation-induced emission effect.

In vitro and in vivo investigations demonstrated this supramolecular theranostic nanomaterial exhibited excellent antitumor efficacy with negligible systemic toxicity.

Read the full article

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Top 10 most-read Polymer Chemistry articles – Q3 2016

This month sees the following articles in Polymer Chemistry that are in the top 10 most accessed from July – September 2016:

Lignocellulosic biomass: a sustainable platform for the production of bio-based chemicals and polymers
Furkan H. Isikgor and C. Remzi Becer
Polym. Chem., 2015,6, 4497-4559
DOI: 10.1039/C5PY00263J

Thiol-ene “click” reactions and recent applications in polymer and materials synthesis
Andrew B. Lowe
Polym. Chem., 2010,1, 17-36
DOI: 10.1039/B9PY00216B

Thiol–ene “click” reactions and recent applications in polymer and materials synthesis: a first update
Andrew B. Lowe
Polym. Chem., 2014,5, 4820-4870
DOI: 10.1039/C4PY00339J

Facile and efficient chemical functionalization of aliphatic polyesters by cross metathesis
Lucie Fournier, Carine Robert, Sylvie Pourchet, Alice Gonzalez, Lewis Williams, Joëlle Prunet and Christophe M. Thomas
Polym. Chem., 2016,7, 3700-3704
DOI: 10.1039/C6PY00664G

Mussel-inspired multifunctional supramolecular hydrogels with self-healing, shape memory and adhesive properties
Zhaowen Li, Wei Lu, To Ngai, Xiaoxia Le, Jing Zheng, Ning Zhao, Youju Huang, Xiufang Wen, Jiawei Zhang and Tao Chen
Polym. Chem., 2016,7, 5343-5346
DOI: 10.1039/C6PY01112H

Investigation into thiol-(meth)acrylate Michael addition reactions using amine and phosphine catalysts
Guang-Zhao Li, Rajan K. Randev, Alexander H. Soeriyadi, Gregory Rees, Cyrille Boyer, Zhen Tong, Thomas P. Davis, C. Remzi Becer and David M. Haddleton
Polym. Chem., 2010,1, 1196-1204
DOI: 10.1039/C0PY00100G

Oxidant-induced dopamine polymerization for multifunctional coatings
Qiang Wei, Fulong Zhang, Jie Li, Beijia Li and Changsheng Zhao
Polym. Chem., 2010,1, 1430-1433
DOI: 10.1039/C0PY00215A

End group removal and modification of RAFT polymers
Helen Willcock and Rachel K. O’Reilly
Polym. Chem., 2010,1, 149-157
DOI: 10.1039/B9PY00340A

The power of light in polymer science: photochemical processes to manipulate polymer formation, structure, and properties
Shunsuke Chatani, Christopher J. Kloxin and Christopher N. Bowman
Polym. Chem., 2014,5, 2187-2201
DOI: 10.1039/C3PY01334K

Toughening of photo-curable polymer networks: a review
Samuel Clark Ligon-Auer, Martin Schwentenwein, Christian Gorsche, Jürgen Stampfl and Robert Liska
Polym. Chem., 2016,7, 257-286
DOI: 10.1039/C3PY01334K

Why not take a look at the articles today and blog your thoughts and comments below.

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Then why not submit to us today!

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In celebration of the 2016 Nobel Prize in Chemistry

The 2016 Nobel Prize in Chemistry was jointly awarded to Jean-Pierre Sauvage, Sir J. Fraser Stoddart and Bernard L. Feringa for their work on the design and synthesis of molecular machines.

Developing the world’s smallest machines: Jean-Pierre Sauvage, Fraser Stoddart and Bernard Feringa

Jean-Pierre Sauvage took the first step towards a molecular machine in 1983, when he successfully  linked two ring-shaped molecules together to form a chain, called a catenane. The molecules in this chain are linked by a mechanical bond, allowing the two interlocked rings to move relative to each other, performing like a tiny machine.

Fraser Stoddart took the second step in 1991, when he developed a rotaxane by threading a molecular ring onto a thin molecular axle. The ring is able to move along the axle enabling a number of developments such as a molecular lift, a molecular muscle and a molecule-based computer chip.

Bernard Feringa took the third step by developing the first molecular motor in 1999 when he got a molecular rotor blade to spin continually in the same direction. Using molecular motors, he has rotated a glass cylinder that is 10,000 times bigger than the motor and also designed a nanocar!

The ground breaking steps taken by the 2016 Nobel Laureates in Chemistry in developing molecular machinery have resulted in a toolbox of chemical structures that can be used by researchers around the world to build anything from artificial switches and release-targeted drugs to novel energy storage systems!

To celebrate these remarkable achievements, we are delighted to present a collection of recent Soft Matter and Polymer Chemistry articles on molecular machines FREE to read until 1 December 2016!

We invite you to submit your best research related to molecular machines to Soft Matter and Polymer Chemistry!

Integrated motion of molecular machines in supramolecular polymeric scaffolds
Xuzhou Yan, Bo Zheng and Feihe Huang
Polym. Chem., 2013, 4, 2395-2399
DOI: 10.1039/C3PY00060E

Research articles
Topological energy storage of work generated by nanomotors
Fabian Weysser, Olivier Benzerara, Albert Johner and Igor M. Kulić
Soft Matter, 2015, 11, 732-740
DOI: 10.1039/C4SM02294G

Hydrodynamics and propulsion mechanism of self-propelled catalytic micromotors: model and experiment
Longqiu Li, Jiyuan Wang, Tianlong Li, Wenping Song and Guangyu Zhang
Soft Matter, 2014, 10, 7511-7518
DOI: 10.1039/C4SM01070A

Construction of muscle-like metallo-supramolecular polymers from a pillar[5]arene-based [c2]daisy chain
Lingyan Gao, Zibin Zhang, Bo Zheng and Feihe Huang
Polym. Chem., 2014, 5, 5734-5739
DOI: 10.1039/C4PY00733F

An acid/base switchable and reversibly cross-linkable polyrotaxane
Shijun Li, Guan-Huan Weng, Wei Lin, Zhi-Bin Sun, Mi Zhou, Bin Zhu, Yang Ye and Jing Wu
Polym. Chem., 2014, 5, 3994-4001
DOI: 10.1039/C4PY00409D

Dual stimuli-responsive supramolecular pseudo-polyrotaxane hydrogels
Lipeng Zhou, Jiaxi Li, Quan Luo, Junyan Zhu, Huixin Zou, Yuzhou Gao, Liang Wang, Jiayun Xu, Zeyuan Dong and Junqiu Liu
Soft Matter, 2013, 9, 4635-4641
DOI: 10.1039/C3SM27776C

pH-responsive dendritic polyrotaxane drug-polymer conjugates forming nanoparticles as efficient drug delivery system for cancer therapy
Yang Kang, Xiao-Mei Zhang, Sheng Zhang, Li-Sheng Ding and Bang-Jing Li
Polym. Chem., 2015, 6, 2098-2107
DOI: 10.1039/C4PY01431F

Phototriggered supramolecular polymerization of a [c2]daisy chain rotaxane
Xin Fu, Rui-Rui Gu, Qi Zhang, Si-Jia Rao, Xiu-Li Zheng, Da-Hui Qu and He Tian
Polym. Chem., 2016, 7, 2166-2170
DOI: 10.1039/C6PY00309E

Also of interest: Find out more about the three Chemistry Nobel Laureates and their research.

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