Polymers and Composites Seminar - Making Biodegradable Polyesters from Sustainable 1,3-Dioxolan-4-ones & Frustrated Lewis Pair Polymers as Responsive Self-healing Gels
| Dates: | 4 September 2019 |
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| Times: | 12:30 - 13:30 |
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| What is it: | Seminar |
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| Organiser: | Department of Materials |
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| Speaker: | Dr Yuechao Xu, Dr Meng Wang |
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Abstract 1:
Poly(-hydroxy acid)s are important biocompatible and biodegradable polymers for drug delivery, tissue engineering and food packaging. In this talk, we will introduce a facile route to a range of
functional poly(-hydroxy acid)s through ring-opening polymerisation of sustainable monomers 1,3-dioxolane-4-ones. The monomers built from ring-closed -hydroxyacids are both easily prepared
and functional group tolerant. We also propose a new mechanism of ring-opening for these monomers, involving competitive elimination and a subsequent Tishchenko reaction facilitated by
formaldehyde. Both catalyst design and polymerisation methodology can be modified to reduce the impact of the Tishchenko reaction, with sterically-unencumbered and electronically-neutral
salen aluminium catalysts exhibiting the best performance. Especially, 5-phenyl-1,3-dioxolane-4-one provides an inexpensive synthetic pathway to the highly desirable isotactic poly(mandelic acid),
as it has been suggested as a biodegradable alternative to polystyrene.
Biography 1:
Yuechao received his master degree in Polymer Chemistry and Physics from Dalian University of Technology in 2013, under the direction of Prof. Xiaobing Lu. Afterwards, he continued his research
to pursue a PhD in the same group working on stereo-selective ring-opening polymerisation to synthesize biodegradable polyesters, and received his PhD degree in Polymer Chemistry and Physics
mid-2017. He joined Michael Shaver’s group as an EPSRC postdoctoral research fellow in August 2017. His research now is focusing on developing catalytic systems for the ring opening polymerization
of novel monomers to form a diverse range of functional polyesters.
Abstract 2:
Frustrated Lewis Pair (FLP) chemistry is an important field of research as it offers a novel route to catalysis and bond activation without metals. Many small molecules show reactivity towards FLPs,
which either form bridges between FLP active centres, or are activated so that they can participate in certain reactions. However, their use as a platform for developing materials chemistry is unexplored.
Our initial effort develops a fully macromolecular FLP, built from linear copolymers that containing either a sterically encumbered Lewis base or Lewis acid as a pendant functional group. The copolymers
were synthesized by copolymerizing styrene with the designed either boron or phosphorous containing monomers. The boron and phosphorous in copolymers cannot react due the steric encumbrance,
hence dissolving of the mixed two copolymers still give a clear solution. This FLPs copolymers solution is proven to work as precursors for network formation, where gelation occurs only when certain
small molecules are added as crosslinkers. The network formed was characterized with different techniques such as rheology and SEM. The gel formed also shows fast self-healing property after physical cracking.
Biography 2:
Meng obtained his BSc degree from the University of Sheffield and completed his master’s degree in polymer science at the same institute in 2015. After that, he moved to the University of Edinburgh
and joined the Shaver Group as a PhD student. He completed his PhD with the GML working on polymeric frustrated Lewis pairs for application in novel stimuli responsive materials and catalysis.
He is now a postdoc with the group at the University of Manchester working on the synthesis of biodegradable polyesters.
The school of materials is hosting a new monthly colloquia series to showcase the research of both internal and external academics at the forefront of polymers and composites research. The seminars
will take place on the first week of every month and is open to all academics, PDRAs and PhD/Masters students in the university. Each lecture is free to attend and no registration is required. Each session
will be 50 minutes in length, followed by a 10 minute Q&A session.
Speakers
Dr Yuechao Xu
Role: Department of Materials
Organisation: The University of Manchester
Dr Meng Wang
Role: Department of Materials
Organisation: The University of Manchester
Travel and Contact Information
Find event
C53
Sackville Street Building
Manchester
