Media type: E-Article Title: Synthesis and characterization of poly(ethylene terephthalate‐co‐isophthalate)s with low content of isophthalate units Contributor: Karayannidis, George P.; Bikiaris, Demetris N.; Papageorgiou, George Z.; Pastras, Socrates V. imprint: Wiley, 2002 Published in: Journal of Applied Polymer Science Language: English DOI: 10.1002/app.11103 ISSN: 0021-8995; 1097-4628 Keywords: Materials Chemistry ; Polymers and Plastics ; Surfaces, Coatings and Films ; General Chemistry Origination: Footnote: Description: <jats:title>Abstract</jats:title><jats:p>The objective of this work was to study the effect of the introduction of low amounts of isophthalate units on the mechanical properties, crystallization rates, and thermal parameters of poly(ethylene terephthalate). For this reason a series of five random poly(ethylene terephthalate‐<jats:italic>co</jats:italic>‐isophthalate) copolymers, containing 0.5, 1, 1.5, 2, and 4 mol % isophthalic acid, were prepared by the melt polycondensation process. The intrinsic viscosity of copolymers ranged between 0.7 and 0.8 dL/g. The increase of isophthalate content resulted in a significant decrease of the crystallization rates, but in a small decline of tensile strength, Young's modulus, and elongation at break, whereas tensile strength at yield point remained almost unaffected. Also, a decrease in the melting point was recorded, whereas the glass‐transition temperature was only very slightly affected. The higher decrease for the aforementioned parameters was noted for the copolymer with 4 mol % isophthalate units content. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1931–1941, 2002</jats:p>