Relationship between the mechanical properties of epoxy/PMMA-b-PnBA-b-PMMA block copolymer blends and their three-dimensional nanostructures
| Autor: | Mitsunori Asada, Shinya Oshita, Hajime Kishi, Y. Nakashima, Jin Imade, Y. Kunimitsu, Yoshihiro Morishita |
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| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
Materials science
Nanostructure Polymers and Plastics General Chemical Engineering Mechanical properties 02 engineering and technology 010402 general chemistry lcsh:Chemical technology 01 natural sciences Polymer blends and alloys Materials Chemistry Copolymer lcsh:TA401-492 lcsh:TP1-1185 Physical and Theoretical Chemistry Composite material Organic Chemistry Epoxy 021001 nanoscience & nanotechnology 0104 chemical sciences visual_art visual_art.visual_art_medium lcsh:Materials of engineering and construction. Mechanics of materials 0210 nano-technology |
| Zdroj: | eXPRESS Polymer Letters, Vol 11, Iss 10, Pp 765-777 (2017) |
| Popis: | Nanostructures of diglycidyl ether of bisphenol-A epoxy/poly(methyl methacrylate)-b-poly(n-butyl acrylate)-b-poly(methyl methacrylate) (PMMA-b-PnBA-b-PMMA) triblock copolymer (BCP) blends were studied in relation to their mechanical properties. Three types of self-assembled nanostructures, such as spheres, random cylinders, and curved lamella, were controlled in phenol novolac-cured epoxy blends with a wide range of BCP content. Three types of nanostructures were observed using two-dimensional and three-dimensional transmission electron microscopy (TEM). The 3D-TEM, dynamic viscoelastic analyses, and theoretical model on the elastic modulus clarified that the spheres and the random cylinders, consisted of epoxy-immiscible PnBA phases, were discontinuously dispersed in the epoxy matrix. In contrast, the curved lamella formed co-continuous nanostructure, in which both the PnBA and epoxy phases formed continuous channels. The fracture toughness (critical strain energy release rate, GIC) and the flexural moduli of elasticity (E) of the cured blends were evaluated for various amounts of BCP content. The highest GIC was obtained from the random cylindrical nanostructured blends in the three types of nanostructures with the same PnBA content. The lowest E was obtained for the curved lamella with co-continuous nanostructures. The details of deformation and fracture events were observed using optical and electron microscopy, and the mechanical properties are discussed in relation to the nanostructures. |
| Databáze: | OpenAIRE |
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