Abstract
A recently reported combined polymerization process of glycidyl methacrylate, mediated by homometallic and heterobimetallic aluminium complexes, naturally produces nano-sized macromolecular assemblies. In this work, the morphological features and the rheological properties of these novel nanoassemblies are studied. The hydrodynamic sizes of the nanoparticles in the solution range from 10 to 40 nm (in numbers), but on a flat surface they adopt a characteristic thin disk shape. The dynamic moduli have been determined in a broad range of temperatures, and the time—temperature superposition applied to obtain master curves of the whole viscoelastic response from the glassy to the terminal regions. The fragility values obtained from the temperature dependence are of m ~40, typical of van de Waals liquids, suggesting a very effective packing of the macromolecular assemblies. The rheological master curves feature a characteristic viscoelastic relaxation with the absence of elastic intermediate plateau, indicating that the systems behaved as un-entangled polymers. The analysis of the linear viscoelastic fingerprint reveals a Zimm-like dynamics at intermediate frequencies typical of unentangled systems. This behaviour resembles that observed in highly functionalized stars, dendrimers, soft colloids and microgels.
Highlights
Glycidyl methacrylate (GMA), is a monomer that deserves a great deal of industrial interest as it presents two functional groups
The results shown in this figure indicate a considerable difference in size among the samples studied, being cPGMA1 sample the smallest one and cPGMA3 the biggest
It is important to note that the PS sample has been selected in such a way that the hydrodynamic size is identical to that measured for cPGMA1 sample
Summary
Glycidyl methacrylate (GMA), is a monomer that deserves a great deal of industrial interest as it presents two functional groups. Functional polymers are a focus of research interest mainly due to their versatility They can be used, for example, for the construction of blocks and new architectures and molecular topologies, including stars, dendrimers and networks or lattices. We studied novel polymeric macromolecular assemblies of soft nanoparticles prepared by a new approach for covalent crosslinking of the network of combs obtained from the ring opening polymerization of GMA. The analysis of the linear viscoelastic fingerprint reveals specific Zimm-like dynamics at intermediate frequencies typical of unentangled systems This behaviour resembles that observed in dendrimers, highly functionalized stars, soft colloids and microgels
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have