Original Paper
Mechanical Properties of Epoxy / Acrylic Block CopolymerBlends; Effect of in-situ Formed Nanophase Structure
2017 Volume 53 Issue 7 Pages 228-234
Details
2017 Volume 53 Issue 7 Pages 228-234
The phase structures of diglycidyl ether of bisphenol-F / 4,4́-methylene-bi（s 2-ethylaniline）（ MBOEA） / poly（methyl methacrylate）-b-poly（n-butyl acrylate）-b-poly（methyl methacrylate）（ PMMA-b-PnBA-b-PMMA）triblock copolymer blends and their mechanical properties were studied. Heat dissolving process of the acrylicBCP in the amine（ MBOEA） generated in-situ carboxylic acids in the PMMA segment of the BCP. The acidvalues in the BCPs were controlled in the dissolving process, which enabled to form different nanostructuresfrom the same composition（ 5wt%BCP） in epoxy/amine mixture. Three types of nanostructures were observedusing transmission electron microscopy（ TEM）, that were curved lamellar structures, coexisting structuresof worm-like micelles and vesicles, and spherical micelles. For the three types of nanostructures, the fracturetoughness（ K1c） and flexural modulus were evaluated. The highest K1c（ =2.5MPa m 1/2） was obtained fromthe coexisting nanostructure of worm-like micelles and vesicles , which was 210% improved in toughnessin comparison with the cured epoxy resin without BCP. Fracture surfaces were observed using optical andelectron microscopy, and the toughening mechanisms were discussed.
