MECHANICAL PROPERTIES OF EPOXY NETWORKS MODIFIED WITH SEMICRYSTALLINE PLANAR MICELLES OF PE-b-PEO

J. PUIG; W. F. SCHROEDER; L. A. FASCE; I. A. ZUCCHI

Cancún

Simposio; XV Simposio Latinomericano de Polímeros, SLAP; 2016

Block copolymers (BCP) have been shown to be highly effective at improving epoxy mechanical properties.1 The BCP modifiers have minimal impact on the glass transition temperature and the modulus and may provide a dramatic increase in the fracture resistance.1 These BCP consist of ?epoxy-philic? and ?epoxy-phobic? blocks and self-assemble within the epoxy matrix to yield a range of nanoscale micelle morphologies, such as spheres, cylinders, vesicles, and lamellas that persist after cure. The type of structure formed depends on the molecular weight, block length, composition, cure cycle employed, and block-block and block-matrix interaction parameters. Although BCP previously have been studied as toughening agents with epoxy resins, most of the BCP studied are in the form of spherical micelles. Only a limited number of investigations have addressed other self-assembled morphologies, such as wormlike micelles.1 For both fundamental research and commercial applications, it is necessary to explore fully the ability of BCP to produce morphologies other than spherical micelles and to investigate their influences on the mechanical properties of cured epoxy matrices.Recently, we reported a strategy based on crystallization-driven self-assembly to generate complex morphologies in an epoxy matrix.2 We showed that depending on the cure temperature and the initial amount of BCP (PE-b-PEO) dispersed in the epoxy resin, a variety of nanostructures with semicrystalline core could be generated, such as a dispersion of disk-like micelles, a concentrated dispersion of platelets, and long nanoribbons partially stacked and oriented in space. The way in which these structures affect fracture resistance and mechanical properties of the resulting epoxy networks is investigated in the present work.