Block self-cross-linkable poly(ethylene terephthalate) copolyester via solid-state polymerization: Crystallization, cross-linking, and flame retardance. (23rd July 2015)

• Record Type: Journal Article
• Authors: Zhao, Hai-Bo; Wang, Xiao-Lin; Guan, Yue; Wang, Xiu-Li; Chen, Li; Wang, Yu-Zhong
• Is Part Of: Polymer. Volume 70(2015)
• Page Start: 68
• Page End: 76
• Publication Date: 2015-07-23
• Subjects: Block copolyester -- Solid-state polymerization -- Crystallization -- Cross-linking -- Flame retardance; Polymers -- Periodicals; Polymerization -- Periodicals; Polymères -- Périodiques; Polymérisation -- Périodiques; 547.7
• DOI: 10.1016/j.polymer.2015.06.012
• Languages: English
• ISSNs: 0032-3861

Abstract

Abstract: A self-cross-linkable poly(ethylene terephthalate) block copolyester (SSP-PETPx) has been synthesized via solid-state polymerization (SSP). In the SSP process, a cross-linkable monomer named 4-(phenylethynyl) di(ethylene glycol) phthalate (PEPE) is incorporated into the amorphous phase of PET. The sequence distribution of the resulted copolyester SSP-PETPx is analyzed with 1 H NMR, showing that the SSP sample possesses block structure. Wide-Angle X-ray diffraction (WAXD) and differential scanning calorimetry (DSC) show that SSP-PETPx is crystallizable benefitting from its block structure, while the corresponding random copolyester (RD-PETP) is totally amorphous. The segments containing PEPE determine the extent of crystallization. Simultaneous thermogravimetric-differential scanning calorimetry (TG-DSC) and rheological analysis prove the cross-linking behaviour of SSP-PETP although the block constitution slightly postpones cross-linking occurrence. The high complex viscosity of the SSP-PETP at 340 °C suggests good flame retardancy and anti-dripping properties. Micro combustion calorimeter (MCC) results prove both SSP-PETP and RD-PETP copolyesters have low flammability, which demonstrates that block structure of SSP-PETP doesn't have a negative impact on the flammability of copolyesters. Graphical abstract: Highlights: A self-cross-linkable PET block copolyester was synthesized via SSP. Benefitting from block structure, the copolyester was crystallizable after SSP. The copolyester kept cross-linking activity and flame retardance simultaneously.