Poly(1,4‐cyclohexylenedimethylene 1,4‐cyclohexanedicarboxylate): Influence of stereochemistry of 1,4‐cyclohexylene units on the thermal properties

Abstract

A series of poly(1,4‐cyclohexylenedimethylene 1,4‐cyclohexanedicarboxylate) (PCCD) samples, characterized by different cis/trans ratio of the 1,4‐cyclohexanedicarbonyl unit, have been synthesized and analyzed by thermogravimetry (TGA), calorimetry (DSC), and X‐ray diffraction (WAXD). The thermal stability results are good and are not affected by the stereochemistry of the 1,4‐cyclohexylene units. On the other hand, the thermal transitions are notably influenced by the cis/trans content. With the increment of the trans content the polymer changes from completely amorphous to semicrystalline material. Tg, Tm, and crystallinity increase. These results suggest that the trans configuration induces a better chain packing and higher symmetry, improving the crystallizability of the samples. The effect of the molecular structure on the thermal properties is analyzed by using a statistical approach. From the effective correlations found between stereochemistry of the C6 rings and transition temperatures it is possible to extrapolate that the configuration of 1,4‐cyclohexylene ring deriving from 1,4‐cyclohexanedicarboxylic acid or dimethyl 1,4‐cyclohexanedicarboxylate results to be the main element responsible for the thermal properties. This is due to the high rigidity of the 1,4‐cyclohexanedicarbonyl unit with respect to 1,4‐cyclohexanedimethyleneoxy unit, deriving from the diol. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 619–630, 2008

Eco‐friendly Poly(butylene 1,4‐cyclohexanedicarboxylate): Relationships Between Stereochemistry and Crystallization Behavior

“…[13] However, isomerization is catalyzed by acids and occurs when the synthesis is performed starting from the diacid, as observed for the synthesis of PCCD starting from CHDA. [9] During the synthesis of PBCHD from DMCD, isomerization is virtually absent.…”

“…In a polymer containing the 1,4-cyclohexylene rings, the cis/trans molar ratio is a crucial parameter that powerfully affects its thermal properties, as observed for PBCHD and for poly(1,4-cyclohexylenedimethylene 1,4-cyclohexanedicarboxylate) (PCCD). [6,9] It will suffice to slightly modify the cis/trans isomeric ratio to prepare polymers whose phase behavior changes from fully amorphous to semicrystalline. Moreover, crystallinity and thermal transitions notably increase by increasing the trans content.…”

“…It is also notable that dimethyl 1,4-cyclohexanedicarboxylate (DMCD) and 1,4-cyclohexane dicarboxylate acid (CHDA), i.e., the monomers we used to introduce the cyclohexylene units in polyesters, [6,9] are now obtained from petroleum resources. However, they can be prepared from bio-based terephthalic acid, starting from limonene and other terpenes.…”

Environmentally Friendly Copolyesters Containing 1,4‐Cyclohexane Dicarboxylate Units, 1‐Relationships Between Chemical Structure and Thermal Properties

“…We have not observed an effect of the cis/trans ratio of the 1,4-cyclohexylene units on the thermal stability of PBCHD, as obtained also for poly(1,4-cyclohexylenedimethylene 1,4-cyclohexanedicarboxylate) (PCCD) samples, which contain two aliphatic rings in the monomeric unit. [30] Moreover, in comparison with PBT, it is interesting to observe that the stability of PBCHD is slightly higher. This result indicates that the substitution of the aromatic ring with an aliphatic ring improves the thermal stability of the materials.…”

Synthesis and Polymerizability of Atom-Bridged Bicyclic Monomers

“…Ring-opening polymerization of an atom-bridged-bicyclic monomer gives a linear polymer containing a ring in the chain. This often imparts desirable physical properties to the polymer, including increased melting point and glass transition temperature [75,76]. Polymerization of bicyclic ether 42 gives a crystalline polymer melting at 250 °C.…”