Natural polymers are playing a key role in the frame for bioeconomy. They could replace fossil-based polymers and make a positive contribution to the mitigation of climate change and the sustainable use of natural resources. This will require a better understanding of how the structure and functionality of the materials interrelate. In this context, this course relates with key topics on:

1. The biomass valorization and natural polymers, including their origin, extraction/isolation, characterization, and physiochemical, structural, mechanical and their biological properties;
2. The development of novel multifunctional bio-based materials architectures and manufacturing processes is also assessed, as well as, their applications in key areas such as biomedicine, composites, agriculture, and environmental engineering are also discussed.

Students acquire the competence to think of biomass valorization and biopolymers as a sustainable alternative to fossil-based polymers for the development of polymeric materials and composites. Basic knowledge in polymer chemistry is beneficial but not necessary. The course content will include a series of lectures using Power Point slides, case studies, exercises and in-class oral presentations by the students. Students should keep up with assigned reading and ask questions in class or by email.

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 Description du cours : 

After a reminder on the different forms of polymer recycling, the mechanical recycling of 4 polymers PE, PP, PET and HIPS will be presented. This second processing of polymer waste from sorting plants is generally based from food packaging. The modification of the macromolecular structure of the different polymers presented is not the same: it depends on the conditions of the process (temperature, shear, residence time). 

Structure du cours : 

Introduction : 

1. Evolution of production global plastic 

2. European production of plastic 

3. Recycling of plastics from packaging 

4. Methods of recycling 

PP recycling : 

From research papers found on SCOPUS with “multiple & extrusions & polypropylene” and ‘’reprocessing & polypropylene’’ as keywords, 5 papers have been selected. Mains results are presented and discussed with the students. 

Recyclability of polyethylene 

1. The different architecture of polyethylene 

2. Viscosity in shear and elongation of polyethylene 

3. PE degradation mechanism during reprocessing (by injection) 

Polyethylene terephthalate 

1. PET Structure and Properties 

1. Chain splitting by hydrolysis  

1. Minimum properties recommended before reprocessing 

1. Regeneration of viscosity by chain extension 

1. Optimization of settings (residence time and concentration) 

1. Long Chain Branching at high concentration of chain extenders 

Two papers on reprocessing of high impact polystyrene are read at the end of this lecture. 

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