Poly(1,4-cyclohexanedimethylene 2,6-naphthalate) polyester with high melting point: Effect of different synthesis methods on molecular weight and properties

Abstract

In the current manuscript, a new approach for the synthesis of poly(1,4-cyclohexanedimethylene 2,6-naphthalate) (PCHDMN) derived from dimethyl 2,6-naphthalenedicarboxylate (2,6-DMN) and 1,4-Cyclohexanedimethanol (CHDM) via melt polycondensation method is introduced. The effect of three different synthesis pathways, polycondensation time and temperature on polyesters molecular weight increase has been investigated. All of the prepared samples were characterized measuring their intrinsic viscosity (IV), thermal properties and morphology with differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD), respectively. The results demonstrated the effectiveness of the synthesis pathway proposed for the preparation of PCHDMN, resulting in high molecular weight (IV value around 0.5 dL/g) and much shorter reaction time. Melt polycondensation temperatures above melting point of polyester should be avoided to be used due to the decomposition of polyester. This was proved by thermogravimetric analysis (TGA) and Pyrolysis-gas chromatography-mass spectroscopy analysis (Py-GC/MS).

Sustainable thermoplastics from renewable resources: Thermal behavior of poly(1,4-cyclohexane dimethylene 2,5-furandicarboxylate)

“…The intrinsic IV of the prepared polyester was measured at 0.46 dL/g. The synthesis of PCHDMN was carried out according to the method described in our previous work [16] wherein 2,6-DMN and CHDM at a molar ratio of 2,6-DMN/CHDM=1/1 were charged in a glass batch reactor with 400 ppm TIS. In the first stage of transesterification, the reaction mixture was heated at 270 o C for 0.5 h under nitrogen atmosphere.…”

“…Terephthalic acid is a widely used monomer for the production of various polyesters of great industrial importance as it is used for a number of polymers, including poly(ethylene terephthalate) PET, poly(butylene terephthalate) (PBT) and poly (1,4-cyclohexane dimethylene terephthalate) (PCHDMT). On the other hand, 1,4cyclohexanedimethanol is a diol that has been used in the production of polyesters with exceptional properties such as poly(1,4-cyclohexane dimethylene terephthalate) (PCHDMT) and poly(1,4-cyclohexane dimethylene naphthalate) (PCHDMN) [9][10][11][12][13][14][15][16].…”

Structure–property relationship of poly(cyclohexane 1,4‐dimethylene terephthalate) modified with high trans‐1,4‐cyclohexanedimethanol and 2,6‐naphthalene dicarboxylicacid

“…The peaks at 1400–1450 cm −1 , 1100 cm −1 , 960 cm −1 , and 740 cm −1 are assigned to CH 2 bending vibrations, COC skeleton asymmetric vibrations of the soft segment, CH stretching vibration of CHDM, and CH vibration of the benzene ring, respectively. Moreover, the absence of a strong detectable band of hydroxyl (–OH) functional groups between 3200 and 3700 cm −1 indicates that polymer samples contain a very low amount of OH at chain end, so indicating that synthesized copolyesters are having reasonable high molecular weights …”

Characterization and Application of Diols Based Liquid Crystalline Copolyester

“…A multiplet at δ=7.62-7.82ppm corresponding to aromatic C-H protons of the phthaloyl moiety respectively 9 . The two singlet peaks at δ = 1.16-1.18ppm were pointed out methyl protons of 2,3-butane diol 11 . A singlet at δ=1.29ppm pointed out might be due to methylene protons respectively.…”