Abstract
The hydrophilic copolyester polyethylene terephthalate (PET) (ENCDP-X) was successfully synthesized by chemical modification consisting of copolymerization and blending and the comonomers, including sodium isophthalate-5-sulfonate (SIPE), polyethylene glycol (PEG), 2,2-dimethyl-1,3-propanediol (NPG) and matting agent TiO2 with different content. Moreover, the structural characterization of sequential structure, crystallization and thermal properties were studied. The results showed that the comonomers were successfully embedded in the copolyester, the actual molar ratio in the copolyester was consistent with the relative feed ratio and the degree of randomness was calculated to be 0.99, showing that the random copolymers synthesized during the melt polycondensation process and the chemical structure was roughly consistent with the expected molecular chain sequence structure. The thermal parameters of the modified copolyester, containing the glass transition temperature (Tg), melting point (Tm), crystallinity (Xc) and thermal degradation temperature, were decreased, and the cold crystallization temperature (Tc) was increased. In addition, with the increasing of the TiO2 content, it improves the thermal performance of the copolyester and it is beneficial to processing and application. The above conclusion is further verified by non-isothermal kinetic analysis. In addition, the copolyester exhibited the better hydrophilicity than pure PET.
Highlights
Polyethylene terephthalate (PET), which is known for its excellent mechanical properties and chemical resistance, consisting of high tenacity, excellent dimensional stability and good heat resistance, have been widely commercialized for many years in the textile industry [1,2,3]
The hydrophilic copolyester was designed and synthesized by introducing additional monomers into the polyethylene terephthalate (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 TiO2 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
Relative to copolyester ENCDP-X, Td, Tdm and the thermal degradation temperature corresponding to the same thermal weight loss rate are lower, owing to the incorporation of modified monomers and
Summary
Polyethylene terephthalate (PET), which is known for its excellent mechanical properties and chemical resistance, consisting of high tenacity, excellent dimensional stability and good heat resistance, have been widely commercialized for many years in the textile industry [1,2,3]. 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]. 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 TiO2 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. The effects of modified monomers on sequential structures, crystalline structures, thermal properties and hydrophilicity of prepared copolyester were mutually compared and elucidated in detail by ubbelohde viscometer, IR-raman spectrometer, nuclear magnetic resonance (1 H- and 13 C-NMR), two-dimensional nuclear magnetic resonance (1 H-13 CCOSY), differential scanning calorimetry (DSC), thermogravimetric analyzer (TGA) and contact angle meter of OCA15EC (China)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
