The Order–Disorder Transition in Graft Block Copolymers

• DOI: 10.1021/acs.macromol.7b02262
• Publication Date: 2017-12-20T13:40:16Z
• Authors: Michael J. Maher; Seamus D. Jones; Aristotelis Zografos; Jun Xu; Haley J. Schibur; Frank S. Bates
• Keywords: Dispersity; Side chain

The order–disorder transitions of diblock copolymers grafted to a common backbone were examined by oscillatory shear rheology and small-angle X-ray scattering. effect grafting density, graft molecular weight, number grafts, dispersity studied using poly[(styrene-alt-N-hydroxyethylmaleimide)-random-(styrene-alt-N-ethylmaleimide)]-graft-poly(4-methylcaprolactone-block-d,l-lactide) [PSHE-g-(P4MCL-PLA)] as model block copolymer. At high densities (25–50%), the temperature (TODT) polymers was nearly identical analogous linear diblock. lower (<25%), TODT found systematically decrease. grafts did not significantly change value TODT; however, increasing resulted in broad, ill-defined transitions. Backbone have little impact on TODT. Ordered morphologies imaged transmission electron microscopy. Long-range order observed with at least 10 grafts/chain.