Fage, Julien (2024)
Understanding the interplay between structure and properties in phase separated copolymer blends prepared by free-radical polymerization.
Technische Universität Darmstadt
doi: 10.26083/tuprints-00026705
Ph.D. Thesis, Primary publication, Publisher's Version
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Item Type: | Ph.D. Thesis | ||||
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Type of entry: | Primary publication | ||||
Title: | Understanding the interplay between structure and properties in phase separated copolymer blends prepared by free-radical polymerization | ||||
Language: | English | ||||
Referees: | Rehahn, Prof. Dr. Matthias ; Pfaendner, Prof. Dr. Rudolf | ||||
Date: | 5 March 2024 | ||||
Place of Publication: | Darmstadt | ||||
Collation: | V, 142 Seiten | ||||
Date of oral examination: | 19 February 2024 | ||||
DOI: | 10.26083/tuprints-00026705 | ||||
Abstract: | Polystyrene is the 6th most widely produced and used plastic in the world. Easy to produce and cost effective, it is a transparent and glassy polymer. However, it suffers from its inherent brittleness, which limits its use in certain applications. Enhancement of its toughness has been a focus in the last few decades. The incorporation of rubber particles in a polystyrene matrix allows to increase the toughness of the material but results in an opaque material. The development of block copolymer such as styrene-butadiene-styrene allowed to enhance further the flexibility and toughness of styrenic polymer, whilst keeping their excellent transparency. However, the method needed to prepare such polymers is cost intensive due to the infrastructures and purity of the reagents needed. This work focusses on the development of graft copolymer prepared by free-radical polymerization. Free-radical polymerization offers numerical advantages compared to controlled polymerization as it does not require demanding conditions in terms of reagent and environment purity. Poly(butyl acrylate) is used as backbone polymer as it offers significant advantage in terms of UV stability in comparison to polybutadiene. As poly(butyl acrylate) does not have functionalities available for grafting with free-radical polymerization, butyl acrylate needs to be copolymerized with a comonomer. 2 routes have been explored for the synthesis of PBA-g-PS: Route A uses a copolymer backbone made of butyl acrylate and allyl methacrylate or DCPA whilst route B uses a copolymer backbone made of butyl acrylate and glycidyl acrylate or glycidyl methacrylate. In route A, the backbone can be used directly for grafting polymer with styrene, using the unreacted allyl or vinyl functionalities n the backbone. In route B, the backbone undergoes polymer analogous reaction where the glycidyl function is converted to acryloyl reactive groups using acrylic acid. The influence of the type of polymerization, emulsion, or solution polymerization is studied for the preparation of the backbone. The graft copolymer blends made of PBA-g-PS and homo-polystyrene are studied in terms of optical and mechanical properties. Transmission electron microscopy is used to determine which type of morphology in the phase separated product is obtained when varying the backbone chemical properties. Finally, the influence of the type of processing, solvent casting or extrusion/injection molding are studied by analyzing the change in mechanical properties as well as the change in morphology. |
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Status: | Publisher's Version | ||||
URN: | urn:nbn:de:tuda-tuprints-267052 | ||||
Classification DDC: | 500 Science and mathematics > 540 Chemistry | ||||
Divisions: | 07 Department of Chemistry > Ernst-Berl-Institut > Fachgebiet Makromolekulare Chemie | ||||
Date Deposited: | 05 Mar 2024 12:31 | ||||
Last Modified: | 06 Mar 2024 13:54 | ||||
URI: | https://tuprints.ulb.tu-darmstadt.de/id/eprint/26705 | ||||
PPN: | 516016547 | ||||
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