Phase Behavior of I₂S Single Graft Block Copolymer/Homopolymer Blends

Abstract

This work is part of an extensive study of model nonlinear block copolymer/homopolymer blends. Effects of graft molecular architecture on the morphology of block copolymer/homopolymer blends have been examined. The single graft Y-shaped block copolymers used in the study are I 2S block copolymers, which have two low polydispersity (PDI) polyisoprene arms and one low PDI polystyrene arm joint at a single junction point. Previously reported linear diblock copolymer/homopolymer blend systems showed that the order-order transitions (OOTs) occur at about the same volume fractions as in pure linear diblock copolymers. The OOT occurs at the same volume fraction regardless of the direction from which it is approached, i.e., blending homopolymer A with a diblock which forms A cylinders in a B matrix to push it toward lamella or blending B homopolymer with a lamellar diblock to push it back toward cylinders. This study shows that when a homopolymer is blended with an I 2S block copolymer, the OOTs split so that they occur at different volume fractions depending up whether they are approached by blending homopolymer into the two-arm or the one-arm side of the block copolymer interface. A perforated lamellar morphology is obtained in a blend of homopolystyrene (hPS) and a lamella forming single graft block copolymer, and it is found to be stable to thermal annealing.

Small-angle X-ray scattering and linear melt rheologyof poly(tert-butyl acrylate-g-styrene) graft copolymers

“…In accordance with experimental literature data, the morphologies of microphase-separated non-linear block copolymer, i.e. graft and star, and even blends of diblock copolymers with homopolymers are dominated in part by either wormlike micelles and spheres or by cylinders but not ordered on a lattice [2, [28][29][30][31][32][33]. Also, more chaotic morpholologies along with disordered bicontinuous structures, and even small grain-like regions of more or less coherent domain orientation were found.…”

Hierarchical Structures of Polystyrene-block-poly(2-vinylpyridine)/Palladium–Pincer Surfactants: Effect of Weak Surfactant–Polymer Interactions on the Morphological Behavior

“…The SAXS data of the PS-b-P2VP 199 (Pd−SCS) x for x ≥ 0.5 ( Figure 3c) shows a broad secondary peak that roughly corresponds to a √3 multiple of the scattering vector of the primary peak, which supports the morphological assignment for these samples to PL. 54,55,62,69,74,103 Figure 4 shows the long period calculated from the position of the primary peaks for all systems involving the 199 kDa PS-b-P2VP. Whereas the long period of the system containing the PDP surfactant initially decreases slightly and then continuously increases with added surfactant (Figure 3a and Figure 4a), 65,104−107 the copolymer periodicities of systems containing the Pd−SCS decreases monotonically with x ( Figure 3c and Figure 4a).…”

“…The expansion of the PS and P2VP domains in both directions can be calculated from the BCP (long) period and by considering the geometry of the interface in the lamellar and cylindrical morphologies. 69,105 In the case of the lamellar morphology (Figure 5a), the effective chain lengths of the PS and P2VP(surfactant) blocks, l PS and l P2VP(surfactant) , respectively, are given by eq 1 and eq 2:…”

Synthesis of Y-shaped amphiphilic copolymers by macromolecular azo coupling reaction

“…[1][2][3][4][5][6][7][8][9][10] Compared to linear amphiphilic block copolymers, Y-shaped copolymers have shown many interesting self-assembly properties due to their unique structures with three building blocks linked to a single junction point. [15][16][17][18][19][20][21][22][23] For example, polymers with well-dened Y-shaped architecture can be prepared by living anionic polymerization and cationic polymerization. [15][16][17][18][19][20][21][22][23] For example, polymers with well-dened Y-shaped architecture can be prepared by living anionic polymerization and cationic polymerization.…”

“…[11][12][13][14] Due to their interesting properties, many efforts have been made to synthesize such Y-shaped block copolymers. [15][16][17][18] With the development of controlled radical polymerization (CRP), Y-shaped block copolymers can also be prepared by CRP methods such as ATRP, RAFT and NMP method. [15][16][17][18] With the development of controlled radical polymerization (CRP), Y-shaped block copolymers can also be prepared by CRP methods such as ATRP, RAFT and NMP method.…”