Melting point depression and cocrystallization behavior of poly(ethylene‐co‐butylene 2,6‐naphthalate) copolymers

Abstract

The melting point depression and cocrystallization behavior of a series of random poly(ethylene‐co‐butylene 2,6‐naphthalate) P(EN‐co‐BN) copolymers were investigated using differential scanning calorimetry (DSC) and wide‐angle X‐ray diffraction (WAXD). These copolymers crystallize over the entire range of composition and they exhibit eutectic behavior. WAXD patterns showed that copolymers form exclusively poly(ethylene 2,6‐naphthalate) (PEN) type crystals or poly(butylene 2,6‐naphthalate) (PBN) type crystals. A transition from the PEN‐ to PBN‐type crystal was observed in the middle of the copolymer composition. This confirms that the P(EN‐co‐BN) copolymers show isodimorphic cocrystallization. The cocrystallization was thermodynamically analyzed using the Wendling–Suter model. The defect free energy was found to be about 12.17 kJ mol−1 in the case of incorporation of BN units in the PEN‐type crystals, and about 5.66 kJ mol−1 in the case of incorporation of EN units in the PBN‐type crystal. This means that the incorporation of bulkier BN units in the PEN crystals is more difficult. For low comonomer concentrations it was found that comonomer exclusion is probable. Copyright © 2004 Society of Chemical Industry

Trans-2-Butene-1,4-Diol as an Olefinic Building Block to Prepare Biobased Unsaturated Copolyesters with High Molecular Weight: Synthesis, Characterization, and Physical Properties

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A numerical investigation of the use of novel melt processed PET‐hemp fiber composites for thermoforming applications

“…The virgin hemp fibers were treated for an hour with 5N NaOH solution in order to increase their thermal stability based on an alternative to the procedure of K. Specht et al . The melting point depression of PET was achieved by blending with 5% (w/w) polycaprolactone in an internal batch mixer (Haake Rheomix, Polylab OS system), based on a previously published method by Papageorgiou et al . The compounding process of alkaline treated fibers and modified PET was done in an internal batch mixer (Haake Rheomix, Polylab OS system, USA), with the melting chamber heated at 250°C.…”

Synthesis and Properties of Novel Biodegradable/Biocompatible Poly[propylene‐co‐(ethylene succinate)] Random Copolyesters

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