Enhancing the physical and structural properties of poly(glycolide-co-trimethylene carbonate-co-ε-caprolactone) copolymer fibers

Abstract

Nowadays, due to the methodological needs in the application of internal surgery new methods evolving novel design for surgical suture are recommended. In this work, the effect of cold drawing process and the thermal annealing process on the different optical and structural properties of surgical suture fibers were studied. For the thermal annealing process, samples of Monosyn monofilaments suture fibers were thermally annealed at temperatures ranging from 50 to 100 $°C$ for annealing time = 120 min. The thermal treatment was carried out under free end condition. For the cold drawing process, an Instron was used to mechanically draw and measures the tensile stress strain curve of Monosyn samples. Using differential scanning calorimetry, X-ray diffraction techniques, and optical polarizing microscope the different properties of the tested sutures, such as the crystallinity, sample radius, birefringence, molecular orientation, and tensile properties were measured. From the resulting data, there was a marked increase in the physical and structural properties during the thermal annealing and cold drawing processes. This means that a new reorientation of Monosyn suture molecular chains were performed and approved by calculating the different orientations f(θ) and f_c . This is an important improvement for these biodegradable materials to widen their medical use and improve their clinical results. RESEARCH HIGHLIGHTS: The stress-strain curve for Monosyn surgical fiber is J shape and identical to the human tissue stress-stain curve. The different orientation calculated improve that the drawing process affect directly on the fiber chain orientations. The fiber chains orientation due to the cold drawing process causes strain induced crystallinity.

Keywords: Monosyn suture fibers; crystallinity; orientation; structural.