About the Semainr:
Combining the properties of parent homopolymers can be accomplished through random copolymerization. However, when the materials are semi-crystalline, complex behavior may arise. The structure and properties of semi-crystalline random copolymers (i.e., PA-ran-PB) depend on their chemical structure. Three general cases have been described in the literature (see Figure below)1: (a) Isomorphism occurs when the chemical structures of PA and PB are very similar, allowing for total inclusion of both comonomers in the crystal lattice or miscibility in the crystalline state. (b) Conversely, when the chemical structures differ significantly, the behavior is largely influenced by the exclusion of comonomer PB from the crystal lattice of PA and vice-versa, indicating total exclusion behavior. (c) Isodimorphic copolymers represent the most intriguing cases, exhibiting intermediate behavior in which partial inclusion of comonomers is permitted, and crystallization can occur across the entire composition range. Isodimorphic copolymers are characterized by a pseudo-eutectic point when the melting point is charted as a function of composition. A crystal structure typical of PA forms to the left of this point, while a PB-type crystal structure is found to the right. The presence of this pseudo-eutectic point means that the melting temperature can be adjusted by the copolymer composition, as well as their crystallinity, crystal structure, and mechanical properties. Recently, we reported a new crystallization mode that combines isomorphic and isodimorphic behavior in aliphatic copolycarbonates. This versatility makes isodimorphic copolymers ideal materials for various applications, including biodegradable films (for copolyesters), thermoplastic elastomers, hot-melt adhesives, and tough semi-crystalline polymers. This seminar will explore the effects of chemical structure, molecular weight, and composition on the structure, morphology, nucleation, and crystallization of a wide range of biodegradable isodimorphic copolyesters and copolycarbonates.
About the Speaker:
Professor Alejandro J. Müller is an IKERBASQUE Research Professor at POLYMAT and the Department of Polymers and Advanced Materials: Physics, Chemistry, and Technology within the Faculty of Chemistry at the University of the Basque Country UPV/EHU in Donostia-San Sebastián, Spain. He has co-authored more than 550 publications in indexed journals, which have attracted over 22,000 citations, giving him an h-index of 77. He has supervised 37 doctoral theses, 62 Master’s theses, and 96 undergraduate theses. Prof. Müller has delivered over 110 keynote, plenary, and invited lectures across around 30 countries. He leads the Polymer Physics and Advanced Manufacturing research area of POLYMAT (https://www.polymat.eu/en/research/Polymer-Physics-Advanced-Manufacturing) and coordinates the Polymer Physics of Advanced Multiphasic Materials group. His research interests include the structure, morphology, nucleation, crystallization, and crystallization kinetics of semicrystalline polymers and multiphase materials, particularly polymer blends, block copolymers, biopolymers, and nanocomposites. Prof. Müller has received several awards, including the international Paul J. Flory Polymer Research Prize. He is a Corresponding Member of the National Academy of Engineering and Habitat of Venezuela (ANIH). In 2021, he was elected as a corresponding member of the Latin American Academy of Sciences (ACAL). In July 2023, the municipality of Beijing, China, awarded him the “Zhongguancun Award for International Cooperation 2022” for his scientific collaboration with the Institute of Chemistry of the Chinese Academy of Sciences (ICCAS). He is an editor of the journal POLYMER (Elsevier), focusing on the joint areas of Polymer Physics and Physical Chemistry
