Phase I and II crystals of poly(p-oxybenzoate). I. Effects of substrate and melt polymerization conditions

Abstract

Acid and base treatment of glass and mica substrates affects the phase II/I crystal structure ratio of poly(p‐oxybenzoic acid) polymerized by the confined thin film melt polymerization (CTFMP) technique; acid treatment of mica enhances the phase I content, whereas base treatment of glass and mica results in growth of 100% phase II crystals. In bulk melt polymerized samples, without added catalyst, the fraction of phase II increases with increasing polymerization temperature, up to 25–30% above 300 °C; this is suggested to be related to a “PH phase” (pseudo‐hexagonal), consisting of 3 pairs of phase I and II crystals, rotated by 60°, in CTFMP samples annealed above their Tk‐m. The addition of a base to the polymerization system also results in an increase in the phase II content, up to almost 100% in some cases. The effect of the addition of base is tentatively attributed to a change in the alignment of neighboring molecules growing out from the initial nucleus during the simultaneous polymerization (liquid crystal) crystallization. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 3520–3531, 1999

Morphology Control of Aromatic Polymers in Concert with Polymerization

“…After polymerization, the sandwiches were slip apart and washed with solvents to remove monomers and oligomers from polymer crystals. The morphology of POB was controlled by the polymerization of ABA in constrained thin films at temperatures between 130 C and 315 C. [115][116][117] Polymerization below the melting point of the ABA,196 C occurred by a sublimation-recrystallization-melting process, with polymerization occurring in the melt. Bilayered lamellar crystals were found, of which the thickness was ca.…”