Processing and characterization of recycled poly(ethylene terephthalate) blends with chain extenders, thermoplastic elastomer, and/or poly(butylene adipate‐co‐terephthalate)

Abstract

Poly(ethylene terephthalate) (PET) resin is one of the most widely used thermoplastics, especially in packaging. Because thermal and hydrolytic degradations, recycled PET (RPET) exhibits poor mechanical properties and lacks moldability. The effects of adding elastomeric modifiers, chain extenders (CE), and poly(butylene adipate‐co‐terephthalate), PBAT, as a toughener to RPET on its moldability and mechanical property were investigated. Melt blending of RPET with CE, thermoplastic elastomer (TPE), and/or PBAT was performed in a thermokinetic mixer (K‐mixer). The blended materials were then injection molded to produce tensile specimens. Various techniques were used to study the mechanical properties, rheological properties, compatibility, and crystallization behavior of the RPET blends. By melt blending with proper additives, recycled PET regained its moldability, thereby enabling the recycling of RPET. Furthermore, the addition of CE greatly enhanced the mechanical properties of RPET. While the RPET and TPE blends also showed improved mechanical properties, the improvement was less significant and the blends were often immiscible due to the difference in polarities between RPET and TPE. Finally, it was found that the mechanical properties of RPET blends depended on the prior thermal history of the material and could be improved with an extra annealing step that increased the degree of crystallinity. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers

Injection molding and characterization of polylactide stereocomplex

“…7. The data obtained from the first heating cycle included the effect of the prior thermal history of the injection-molded samples, while the data obtained from the second heating cycle allowed for a direct comparison of the crystallization behavior of different materials after erasing the thermal history through the first heating scan [19].…”

Melt rheology and properties of compatibilized recycled poly(ethylene terephthalate)/(styrene‐ethylene‐ethylene‐propylene‐styrene) block copolymer blends

“…As a semicrystalline polyester, PET is widely used in various applications, such as bottles, films, and fibers [6,7]. Because of the widespread use of these materials, particularly for soft drink bottles, it is necessary to take action to deal with postconsumer bottles as well as the increasing concerns over the environmental impact and anticipated oil shortage.…”

A study on the fracture, mechanical and thermal properties of chain extended recycled poly(ethylene terephthalate)

“…1,20,21 In the literature, it appears that especially GMA-based impact modifiers are widely used for polyesters (such as PET) because of the reaction tendency between glycidyl functionality and terminal groups of polyesters. 22, 23 Xanthos et al 22 used diimidodiepoxide as a novel chain extender for PET and compared reactivity of diimidodiepoxide with that of GMA copolymer.…”