Synthesis and characterisation of copolyesters from poly(ethylene terephthalate) and poly(hexamethylene terephthalate)

Abstract

Copolyesters containing poly(ethylene terephthalate) and poly(hexamethylene terephthalate) (PHT) were prepared by a melt condensation reaction. The copolymers were characterised by infrared spectroscopy and intrinsic viscosity measurements. The density of the copolyesters decreased with increasing percentage of PHT segments in the backbone. Glass transition temperatures (Tg). melting points (Tm) and crystallisation temperatures (Tc) were determined by differential scanning calorimetry. An increase in the percentage of PHT resulted in decrease in Tg, Tm and Tc. The as‐prepared copolyesters were crystalline in nature and no exotherm indicative of cold crystallisation was observed. The relative thermal stability of the polymers was evaluated by dynamic thermogravimetry in a nitrogen atmosphere. An increase in percentage of PHT resulted in a decrease in initial decomposition temperature. The rate of crystallisation of the copolymers was studied by small angle light scattering. An increase in percentage of PHT resulted in an increase in the rate of crystallisation.

Poly(ethylene Terephthalate)/Poly(alkylene Terephthalate) Copolyester Fibers: Sorption and Dyeability

“…The main factors governing , the dyeing behavior of polymers are crystallinity, orientation, and size of crystalline region, as well as the mobility of the polymer chains characterized by the glass transition temperature. Thus the total number of amorphous regions and the accessibility of these regions control the dye uptake and moisture absorption in hydrophobic fibers such as poly(ethylene terephthalate) [2].In our earlier papers, we have reported the changes in the Tg, T & d q u o ; & d q u o ; and fine structure of PET by incorporating a low mole fraction of a comonomer in the backbone [5,6,7,8,9,11 ]. The comonomer unit disturbs the packing of molecular chains, thereby decreasing the crystallinity and orientation and increasing the amorphous regions.…”

“…In our earlier papers, we have reported the changes in the Tg, T & d q u o ; & d q u o ; and fine structure of PET by incorporating a low mole fraction of a comonomer in the backbone [5,6,7,8,9,11 ]. The comonomer unit disturbs the packing of molecular chains, thereby decreasing the crystallinity and orientation and increasing the amorphous regions.…”

Síntesis, caracterización y aplicaciones biomédicas de redes de copolímeros basados en poliésteres.

“…Varma y sus colaboradores [17][18][19][20][21][22][23] han reportado la obtención de copolímeros al azar de altos pesos moleculares no biodegradables de poli (etilen tereftalato) (PET) con tetra-/hexa-/octa-/ poli(etilen glicol) mediante el método de policondensación. Otros autores [24][25][26] han publicado diferentes estudios de copolímeros que contienen fracciones de poliésteres alifáticos y aromáticos y que combinan tanto sus propiedades mecánicas como degradativas.…”