Epoxy-functionalized star-shaped polymers as novel tougheners for epoxy resin

Abstract

A novel epoxy resin toughener based on star-shaped copolymer of butyl acrylate (BA) and glycidyl methacrylate (GMA) [poly (BA-co-GMA)] with low viscosity was developed. The star polymers were synthesized by initiators for continuous activator regeneration atom transfer radical polymerization (ICAR ATRP) using tri, tetra and hexa-functional initiators. The branching parameters of star poly (BA-co-GMA) were characterized by gel permeation chromatography with a laser light scattering-viscometry triple detection system. Copolymer composition and glass transition temperatures of the copolymers were analyzed by proton nuclear magnetic resonance ( 1 H-NMR) and differential scanning calorimetry (DSC), respectively. The results showed that the branching ratio decreased as the number of arms increased. The epoxide groups of the GMA units were kept intact during ICAR ATRP. Rheological, mechanical tests and dynamic mechanical analysis revealed that star poly (BA-co-GMA)/diglycidyl ether of bisphenol A (DGEBA) epoxy resin formulation exhibited better processability, higher impact resistance and thermal resistance than those of linear poly (BA-co-GMA)/DGEBA epoxy resin formulation.

A Carboxyl-Terminated Polybutadiene Liquid Rubber Modified Epoxy Resin with Enhanced Toughness and Excellent Electrical Properties

“…Figure 6b-d illustrates the whitening region that implies plastic deformation and spherical shapes, which indicate holes and cavities. 5,25 The plastic deformation and holes account for its excellent impact strength, as there is an energy dissipation mechanism operating here. 8 This stress whitening effect may be related to the local deformation at the crack tip, and holes in the stress whitened region presumably resulted from the rupture of elastomeric particles.…”

Enhancement of Epoxy Thermosets with Hyperbranched and Multiarm Star Polymers: A Review

“…al. [ 142 ] synthesized 3, 4, and 6-arm stars with glycidyl methacrylate arms by ATRP. The epoxy groups in the arms and the epoxy resin could react with 4,4′-diamino diphenyl sulphone and the materials obtained presented higher impact resistance than their linear analogous.…”

“…Regarding the viscosity of formulations, the addition of MASPs as modifiers in epoxy resins leads to smaller increases than their linear analogs. Ren et al [ 142 ] could observe that the viscosity of the formulations decreased on increasing the number of arms in well-defined stars and that the effect was lower than in the case of adding an analogous linear polymer. This result was attributed to the lower inter and intra-macromolecular entanglement of the MASP in comparison to the linear counterpart.…”

Preparation and In Vitro Drug Release Behavior of 1,10-Phenanthroline/β-cyclodextrin–poly (Glycidyl Methacrylate) Drug-Loaded Microspheres

“…Nevertheless, star-shaped polymers have recently attracted considerable attention as drug carriers owing to its dense molecular structure with moderate flexibility [22]. Moreover, they have been widely used as model branched polymers for evaluating the effect of segment density and chain topology on polymer properties [23,24]. Typically, star-shaped polymers are synthesized by two major pathways: "core-first" and "arm-first" approaches [24,25].…”