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Summary

This MSCA Individual Fellowship aims to unlock the potential of natural biopolymers such as chitosan, cellulose, and alginate, which have been increasingly appreciated for not only their renewability (in contrast to petroleum-derived polymers), but also their chemical versatility and unique properties (e.g. biodegradability, antimicrobial activity, and biocompatibility), which are advantageous for certain applications (e.g. biomedical, environmental, and agricultural). However, these biomass resources have long been underutilised because of the key challenges associated with processing and overall material performance. Typically, it is extremely challenging to manufacture high-performance biopolymer materials cost-effectively.

The wide adoption of biopolymers as renewable resources could largely benefit society by contributing to sustainability and the bioeconomy. The research into biopolymers can deliver solutions to transform the plastic industry for a circular economy, reducing environmental pollution caused by traditional, petroleum-based synthetic polymers, and delivering new, functional materials for improving people’s health and life.

This fellowship specifically focused on creating high-performance biopolymer composites via novel, cost-effective engineering processes, paving the way for their wide applications. The overall objectives were to 1) understand the physicochemical interactions between biopolymers, nanofillers and plasticisers under “melt” processing conditions and the impact of these interactions on material structures and properties, and 2) establish a cost-effective “melt” processing technology for constructing biopolymer-based materials with tailored properties and enhanced functionality.

A parallel goal of this fellowship is to enable substantial transfer of knowledge and skills between the Fellow (Dr D F Xie) and the host (University of Warwick) and provide the Fellow with widened competencies for research independence and maturity.

This fellowship has not only led to new and important knowledge in (bio)polymer science and engineering, but also allowed the Fellow to achieve broadened expertise, develop new collaborative links, and acquire various transferable skills, which will definitely benefit his future career.

Research highlights

1. Cost-effective, thermomechanical processing method to construct biopolymer composites demonstrated;
2. Factors determining nanofiller dispersion in biopolymers identified;
3. Mechanisms regarding nanofiller reinforcement effect on biopolymers revealed;
4. The influence of material formulation (nanofiller, plasticiser, and biopolymer blending) on surface hydrophilicity uncovered;
5. Competing interactions among biopolymer, nanofiller and plasticiser elaborated;
6. Unexpected structures and properties of biopolymer composites (e.g. hydrolytic stability and high relative permittivity) shown.

Journal publications

• Chen, P., Xie, F.*, Tang, F., & McNally, T.* (2021). Ionic liquid-plasticised composites of chitosan and hybrid 1D and 2D nanofillers. Functional Composite Materials, 2, 14. https://doi.org/10.1186/s42252-021-00026-0 [Gold OA] [Repository Link: WRAP]
• Chen, P., Xie, F.*, Tang, F., & McNally, T.* (2021). Cooperative effects of cellulose nanocrystals and sepiolite when combined on ionic liquid plasticised chitosan materials. Polymers, 13(4), 571. https://doi.org/10.3390/polym13040571 [Gold OA] [Repository Link: WRAP]
• Chen, P., Xie, F.*, Tang, F., & McNally, T.* (2021). Influence of plasticiser type and nanoclay on the properties of chitosan-based materials. European Polymer Journal, 114, 110225. https://doi.org/10.1016/j.eurpolymj.2020.110225 [Gold OA] [Repository Link: WRAP]
• Chen, P., Xie, F.*, Tang, F., & McNally, T.* (2021). Graphene oxide enhanced ionic liquid plasticisation of chitosan/alginate bionanocomposites. Carbohydrate Polymers, 253, 117231. https://doi.org/10.1016/j.carbpol.2020.117231 [Gold OA] [Repository Link: WRAP]
• Chen, P., Xie, F.*, Tang, F., & McNally, T.* (2020). Structure and properties of thermomechanically processed silk peptide and nanoclay filled chitosan. Nanocomposites, 6(3), 125-136. https://doi.org/10.1080/20550324.2020.1820796 [Gold OA] [Repository Link: WRAP]
• Chen, P., Xie, F.*, & McNally, T.* (2021). Understanding the effects of montmorillonite and sepiolite on the properties of solution-cast chitosan and chitosan/silk peptide composite films. Polymer International, 70(5), 527-535. https://doi.org/10.1002/pi.6103 [Gold OA] [Repository Link: WRAP]
• Chen, P., Xie, F.*, Tang, F., & McNally, T.* (2020). Ionic liquid (1-ethyl-3-methylimidazolium acetate) plasticization of chitosan-based bionanocomposites. ACS Omega, 5(30), 19070-19081. https://doi.org/10.1021/acsomega.0c02418 [Gold OA] [Repository Link: WRAP]
• Chen, P., Xie, F.*, Tang, F., & McNally, T.* (2020). Glycerol plasticisation of chitosan/carboxymethyl cellulose composites: Role of interactions in determining structure and properties. International Journal of Biological Macromolecules, 163, 683-693. https://doi.org/10.1016/j.ijbiomac.2020.07.004 [Gold OA] [Repository Link: WRAP]
• Chen, P., Xie, F.*, Tang, F., & McNally, T.* (2020). Unexpected plasticization effects on the structure and properties of polyelectrolyte complexed chitosan/alginate materials. ACS Applied Polymer Materials, 2(7), 2957-2966. https://doi.org/10.1021/acsapm.0c00433 [Gold OA] [Repository Link: WRAP] [Full text: ACS Articles on Request]
• Chen, P., Xie, F.*, Tang, F., & McNally, T.* (2020). Structure and properties of thermomechanically processed chitosan/carboxymethyl cellulose/graphene oxide polyelectrolyte complexed bionanocomposites. International Journal of Biological Macromolecules, 158, 420-429. https://doi.org/10.1016/j.ijbiomac.2020.04.259 [Gold OA] [Repository Link: WRAP]
• Chen, P., Xie, F.*, Tang, F., & McNally, T.* (2020). Thermomechanical-induced polyelectrolyte complexation between chitosan and carboxymethyl cellulose enabling unexpected hydrolytic stability. Composites Science and Technology, 189, 108031. https://doi.org/10.1016/j.compscitech.2020.108031 [Gold OA] [Repository Link: WRAP]

Conference presentations

• “Thermomechanically processed, polyelectrolyte complexed biopolymer nanocomposites with unexpected hydrolytic stability”, Frontiers in Green Materials, 7-11 Dec 2020, Online
• “Biopolymer polyelectrolyte complexed nanocomposites prepared by melt processing with unexpected hydrolytic stability”, 16^th Pacific Polymer Conference (PPC16), 8-12 Dec 2019, Singapore (PPC16-A-0934) [Invited oral presentation]
• “Biopolymer polyelectrolyte complexed nanocomposites prepared by melt processing with unexpected hydrolytic stability”, 37th Australasian Polymer Symposium (APS37), 10-13 Nov 2019, Sunshine Coast, Australia (p.113) [Oral presentation]
• “Competing interactions in hybridised-biopolymer nanocomposites”, 7^th International Conference on Biobased and Biodegradable Polymers (BIOPOL2019), 17-19 Jun 2019, Stockholm, Sweden (Oral Communication 23) [Oral presentation]

Workshop presentations

• “How Coronavirus May Have Made the Future More Plastic”, Ringier Plastic Event “Global Epidemic Control: Challenges and Opportunities for Medical Plastic Manufacturing”, 22-23 Jun 2020, Online [Invited oral presentation] [Day 1 video; Day 2 video]

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