We report a catalytic system that produces olefin block copolymers with alternating semicrystalline and amorphous segments, achieved by varying the ratio of alpha-olefin to ethylene in the two types of blocks. The system uses a chain shuttling agent to transfer growing chains between two distinct catalysts with different monomer selectivities in a single polymerization reactor. The block copolymers simultaneously have high melting temperatures and low glass transition temperatures, and therefore they maintain excellent elastomeric properties at high temperatures. Furthermore, the materials are effectively produced in economically favorable, continuous polymerization processes.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1126/science.1125268 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Responsive Surfactant-Driven Morphology Transformation of Block Copolymer Microparticles.
Chemistry
January 2025
Huazhong University of Science and Technology, 1037 Luoyu Road, 430074, Wuhan, CHINA.
Block copolymer (BCP) microparticles, which exhibit rapid change of morphology and physicochemical property in response to external stimuli, represent a promising avenue for the development of programmable smart materials. Among the methods available for generating BCP microparticles with adjustable morphologies, the confined assembly of BCPs within emulsions has emerged as a particularly facile and versatile approach. This review provides a comprehensive overview of the role of responsive surfactants in modulating interfacial interactions at the oil-water interface, which facilitates controlled BCP microparticle morphology.
View Article and Find Full Text PDFTargeted Polymer-Peptide Conjugates for E-Selectin Blockade in Renal Injury.
Pharmaceutics
January 2025
Department of Clinical Biochemistry and Pharmacology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel.
Background/objectives: Leukocytes play a significant role in both acute kidney injury (AKI) and chronic kidney disease (CKD), contributing to pathogenesis and tissue damage. The process of leukocyte infiltration into the inflamed tissues is mediated by the interactions between the leukocytes and cell adhesion molecules (CAMs, i.e.
View Article and Find Full Text PDFEffects of Additional Flexible and Rigid Structure on BDT-BDD Terpolymer and the Performance of Organic Solar Cells.
Polymers (Basel)
January 2025
School of Materials Science and Engineering, Ocean University of China, Qingdao 266100, China.
In organic solar cells, the aggregation and crystallization of polymers are significant for bulk heterojunction. Blending with acceptor materials, polymer donor materials can adjust their aggregation by the movement of the chain segments. In this paper, the unfused structures based on thiophene and carbazole are respectively designed and introduced into the donor-acceptor copolymer donor materials to investigate the influence of flexible and rigid structures on polymer-aggregation leading photoelectric performance.
View Article and Find Full Text PDFMetal-Coordinated Polymer-Inorganic Hybrids: Synthesis, Properties, and Application.
Polymers (Basel)
January 2025
Department of Materials Science and Engineering, Iowa State University, Ames, IA 50011, USA.
This review examines the recent advancements and unique properties of polymer-inorganic hybrid materials formed through coordination bonding (Class II hybrids), which enable enhanced functionality and stability across various applications. Here, we categorize these materials based on properties gained through complexation, focusing on electrical conductivity, thermal stability, photophysical characteristics, catalytic activity, and nanoscale self-assembly. Two major synthetic approaches to making these hybrids include homogeneous and heterogeneous methods, each with distinct tradeoffs: Homogeneous synthesis is straightforward but requires favorable mixing between inorganic and polymer species, which are predominantly water-soluble complexes.
View Article and Find Full Text PDFPolymeric Polylactic Acid-Glycolic Acid-Based Nanoparticles Deliver Nintedanib Across the Blood-Brain Barrier to Inhibit Glioblastoma Growth.
Int J Mol Sci
January 2025
The Second Hospital & Clinical Medical School, Lanzhou University, Lanzhou 730030, China.
The aim of this study was to investigate the inhibitory effect of nintedanib (BIBF) on glioblastoma (GBM) cells and its mechanism of action and to optimize a drug delivery strategy to overcome the limitations posed by the blood-brain barrier (BBB). We analyzed the inhibition of GBM cell lines following BIBF treatment and explored its effect on the autophagy pathway. The cytotoxicity of BIBF was assessed using the CCK-8 assay, and further techniques such as transmission electron microscopy, Western blotting (WB), and flow cytometry were employed to demonstrate that BIBF could block the autophagic pathway by inhibiting the fusion of autophagosomes and lysosomes, ultimately limiting the proliferation of GBM cells.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!