The bulk mechanical properties of linear triblock and pentablock copolymers that self-assemble into hexagonally packed cylinders with glassy, unentangled matrices of poly(cyclohexylethylene) (PCHE for a homopolymer, C for a block copolymer) with rubbery poly(ethylene-alt-propylene) (P) and semicrystalline polyethylene (E) minority components are examined. The tensile properties of high C content CEC triblock copolymer could not be quantified; however, CPC can plastically deform under uniaxial strain, unlike brittle PCHE. Both CECEC and CPCPC pentablock copolymers exhibited ductile tensile behavior, but the tensile properties of blends of these two pentablock copolymers show that the addition of crystallinity in the minority phase prevents strain softening after yielding and necking, which indicates that these samples deform only via crazing. On the other hand, the white gage region of CPCPC and the ability of CPCPC to neck indicate that high C content materials deform via shear yielding and crazing when the minority component is a rubbery material. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012 Many applications require a polymer that simultaneously exhibits high modulus, ductility, optical clarity, and thermal stability. In order to create materials that fulfill these requirements, linear triblock and pentablock copolymers that self-assemble into glassy, unentangled matrices of poly(cyclohexylethylene) (C) with hexagonally-packed cylinders of rubbery poly(ethylene-alt-propylene) (P) or semicrystalline polyethylene (E) were synthesized and characterized. This article reports the effect of the architecture and the state of the minority component on the bulk mechanical properties.
|Original language||English (US)|
|Number of pages||12|
|Journal||Journal of Polymer Science, Part B: Polymer Physics|
|State||Published - May 15 2012|
- block copolymers
- glassy polymers
- mechanical properties