Mesomorphic Structures in Flexible Polymer−Surfactant Systems Due to Hydrogen Bonding:  Poly(4-vinylpyridine)−Pentadecylphenol

Abstract

Properly selected hydrogen bonding suffices to induce mesomorphic structures in mixtures of flexible polymers and nonmesogenic surfactants. For poly(4-vinylpyridine)-3-pentadecylphenol (P4VP-(PDP)x) complexes, the long period of the lamellar structure decreases as x -1 (x is the number of PDP molecules per P4VP repeat unit) in complete contrast to similar polyelectrolyte systems. Upon cooling from 80 °C to the room temperature, the long period gradually increases and levels off at around 30 °C at a value which is approximately 4 Å above the starting value. After an induction time, a structural transformation occurs in the highly complexed samples, due to the crystallization of the alkyl side chains. It is accompanied by a sudden decrease in the long period of approximately 5 Å. However, the structure is not stable and after an additional induction time both structures are present in the samples. Arguments to explain most of the observed phenomena will be given.

On lyotropic behavior of molecular bottle-brushes: A Monte Carlo computer simulation study

“…The main chain beads from which a side chain is grafted were chosen equally along the backbone, i.e., every other main chain bead carried a side chain. Side chains of lengths M ϭ 0, 4,6,8,10,12,16, and 20 were considered. The initial conformation was created in the following way.…”

“…Another related but quite different set of systems was obtained by various groups in a much simpler way using strong physical association between end-functionalized oligomeric chains and homopolymers. [3][4][5][6][7][8][9][10][11] Compared to the former systems, the oligomeric side chains used so far are, however, considerably smaller.…”

“…The hydrogen bonding systems are characterized by a somewhat weaker repulsion between the associated side chains and the polymer backbone and, therefore often exhibit order-disorder transitions in the melt. 8,9,11 The unfavorable interactions between the polar and nonpolar groups of the polyelectrolyte complexes are in general large and the systems studied so far all exhibit a microphase separated ordered state. [3][4][5][6][7]12 No order-disorder transitions have been observed.…”

Solid state nanofibers based on self-assemblies: from cleaving from self-assemblies to multilevel hierarchical constructs

“…Even more importantly, PPE promotes entanglements, and therefore addition of minor fractions of PPE leads to reinforcement, as discussed by van Zoelen et al 18 In order to facilitate simple cleaving, the matrix phase is selected to be poly(4-vinylpyridine) (P4VP) as complexed with alkylphenol: It is well documented based on FTIR that phenols form hydrogen bonds with pyridines, see e.g. ref 51. Differential scanning calorimetry shows that alkylphenols, such as dodecylphenol (DDP) or pentadecylphenol (PDP) plasticize P4VP due to the supramolecular spacer-like side chains.…”

“…If the nonpolar side chain is long enough, such as in PDP, lamellar self-assemblies of P4VP(PDP) 1.0 are obtained due to the long repulsive side chains. 51 In fact, in PS-b-P4VP(PDP) 1.0 a hierarchical self-assembly at the block copolymer length scale (10-100 nm) and surfactant length scale (ca. 3 nm) takes place.…”