RESUMO
Poly(ethylene terephthalate) (PET) is one of the most prevalent polymers in the world due to its combined thermal, mechanical, and gas barrier attributes. Blending PET with other polymers is an appealing strategy to further tailor properties to meet the needs of an even more diverse range of applications. Most blends with PET are macrophase-separated; only a few miscible systems have been reported. Here, the miscibility of the aromatic polyesters poly(salicylic glycolide) (PSG) and poly(salicylic methyl glycolide) (PSMG) with PET is described. Both PSG and PSMG have similar chemical structures to PET but are derived from sustainable resources and readily degradable. This study suggests that they are fully miscible with PET over the entire composition range, which is attributed to favorable interactions with PET. Negative polymer-polymer interaction parameters (χ) were determined using Flory-Huggins theory to describe melting temperature variations in the blends. In addition, the PET blends showed mechanical properties that are intermediate between the two homopolymers.
RESUMO
Coblation devices are now widely used in arthroscopic surgery and they show a very low incidence of intraoperative complications. We experienced a case where the tip of the wand separated and migrated into the posterior knee compartment in an arthrofibrotic knee. The free wand tip was identified and then extricated from the popliteal hiatus of the knee with using C-arm fluoroscopic control. To the best of our knowledge, this is the first report of its kind involving coblation wands. We describe this complication to show that the use of coblation devices can lead to unexpected problems and it is imperative to inspect all instruments before and after each surgical use.