Isothermal crystallization and melting behavior of 2‐methyl‐1,3‐propanediol substituted sulfonated poly(ethylene terephthalate) copolyesters

Abstract

Poly(ethylene terephthalate) copolyesters (abbreviated as MCDP) containing 2-methyl-1,3-propanediol (MPD) and sodium-5-sulfo-bis-(hydroxyethyl)-isophthalate (SIP) units were synthesized through a direct polycondensation reaction. Chemical compositions of the copolyesters were determined by 1 H-and 13 C-NMR spectroscopy, respectively. Thermal properties and isothermal crystallization behavior were characterized using DSC analysis. Results exhibited that the crystallization rate of MCDP copolyesters was depressed with increasing MPD content. The equilibrium melting temperature of MCDP copolyesters showed a marked decrease when the composition of MPD increased, indicating the incorporation of MPD units lead to less perfect crystals. The crystal structure was investigated via using WAXD patterns. It was confirmed that MPD and SIP can not enter into the crystal region. The crystal morphology observed by using POM clearly showed that the presence of MPD units depressed the crystallization ability of MCDP copolyesters.

Structures and properties of easily dyeable copolyesters and their fibers respectively modified by three kinds of diols

“…The WAXD analysis was used to investigate the crystal structure of different copolyester fibers, and the WAXD patterns were shown in Figure 6, together with the deconvoluted peaks using PeakFit v4 curve‐fitting software. The diffraction peaks of CDP fiber at 2θ of 18, 22.5, and 25.9°, which were also the characteristic diffraction peaks of triclinic PET, corresponding to (010), (1ī0), and (010) reflection planes, respectively, suggesting that SIP unit did not pack into the original polyester unit cell 12,28. The diffraction peaks of PCDP, MCDP, and NCDP fibers were not found to obviously shift except for the diffraction intensities when compared with that of CDP fiber, suggesting that the crystal structure in each copolyester fiber was also triclinic system in the same manner as PET.…”

“…The diffraction peaks of CDP fiber at 2h of 18, 22.5, and 25.9 , which were also the characteristic diffraction peaks of triclinic PET, corresponding to (010), (1ī0), and (010) reflection planes, respectively, suggesting that SIP unit did not pack into the original polyester unit cell. 12,28 The diffraction peaks of PCDP, MCDP, and NCDP fibers were not found to obviously shift except for the diffraction intensities when compared with that of CDP fiber, suggesting that the crystal structure in each copolyester fiber was also triclinic system in the same manner as PET. Therefore, only the PET segments in each copolyester fiber were capable of crystallization, and PDO, MPD, and NPG units, as well as SIP unit, were excluded from the crystal regions.…”

“…One really impressive demonstration for improvement of CDP cationic dyeability is incorporating 2‐methyl‐1,3‐propanediol (MPD) into CDP backbone, which is a novel approach to increase the accessiblity for dye molecule 12,13. Three kinds of diols, i.e.…”

Synthesis and structure analysis of polyesteramides modified with bio-based diaminopentane hexanedioic salt

“…The intrinsic viscosity of polyesteramides is between 0.62 and 0.78 dl/g (as seen in Table 2) which is the suggested range (0.55~0.80 dl/g) of intrinsic viscosity appropriate for spinning polyester. (6). During the synthetic process, EG was hydrolyzed to produce DEG as follows.…”

Synthesis and Structural Characterization of Sequential Structure and Crystallization Properties for Hydrophilic Modified Polyester

“…In our previous research, it was showed that the incorporation of monomer dimethyl-1,3-propylene glycol (MPD/NPG) in the polymerization process led to less perfect crystals and reducing the crystallinity, improving the hydrophilic properties of the copolyester [4,17]. In this work, the hydrophilic copolyester was designed and synthesized by introducing additional monomers into the PET molecular chain to improve the hydrophilic properties of the fibers, combining chemical modification methods of copolymerization and blending by incorporating 2,2-dimethyl-1,3-propanediol (NPG) as a branched modified monomer to further reduce the crystallinity and increase the binding capacity with water, and blending TiO 2 to provide access with water and further improve the hydrophilicity, based on diethylene isophthalate-5-sulfonate (SIPE) and polyethylene glycol (PEG-2000), increasing from the more aspects hygroscopicity of modified polyester.…”