Influence of the molecular weight of polymer, solvents and operational condition in the electrospinning of polycaprolactone

Abstract

ABSTRACT:The objective of this study was to determine the influence of the molecular weight of polycaprolactone, solvents and operational conditions to obtain polymeric nanofibers by the electrospinning technique. In this study, an electrospinning equipment constructed at University was employed, in which you can control the process parameters such as voltage, deposition rate, collector distance, speed and direction of rotation of the collector. In this paper, polycaprolactone (PCL) of three different Molecular Weight (Mw=14,000 g·mol , and Mw=80,000 g·mol -1 ) was used. Solvents used were Acetone and mixtures of Acetone with Acetic Acid in different ratios. The tests carried out showed that polycaprolactone of 14,000 g·mol -1 did not allow getting fibers. While the tests carried out with polycaprolactone of 45,000 g·mol -1 and 80,000 g·mol -1 allowed getting fibers under the different conditions evaluated. The higher concentration of the polymer provokes the solution of the polymer does not flow through the tip of the syringe, while the low concentration of the polymer favors that the fibers break and defects appear in the film. In this study, it was found that using a voltage of 15 KV, an injection rate of 0.1 mL/h and a collector distance from 15 cm with PCL solution of 45,000 g·mol -1 at 20% in solution 1:1 of acetone and acetic acid, it was possible to obtain the highest percentage of nanofibers from all experiments (77%) with an average diameter of 88 nm. RESUMEN:El objetivo de este trabajo fue determinar la influencia del peso molecular de la policaprolactona, solventes y condiciones operacionales para obtener nanofibras poliméricas mediante la técnica de electrospinning. Para este trabajo, se utilizó un equipo de electrospinning construido en la Universidad Pontificia Bolivariana, en el cual se pudieron controlar los parámetros del proceso como el voltaje, la velocidad de deposición y la distancia del colector. Además, para este trabajo se utilizó policaprolactona (PCL) de tres pesos moleculares diferentes (Mw = 14.000 g·mol ). Los disolventes empleados fueron acetona y mezclas de acetona con ácido acético en diferentes proporciones. Los ensayos realizados mostraron que la policaprolactona de 14.000 g·mol -1 bajo ninguna de las condiciones evaluadas permitió obtener fibras, mientras que los ensayos realizados con policaprolactona de 45.000 y 80.000 g·mol -1 sí permitieron obtener fibras bajo las diferentes condiciones evaluadas. La mayor concentración del polímero dificulta el paso de la solución por punta de la jeringa, mientras que la baja concentración del polímero favorece que las fibras se rompan y aparezcan gotas en la película. En este estudio se encontró que, empleando un voltaje de 15 KV, un flujo de inyección de 0,1 mL/h y una distancia del colector de 15 cm para una solución de PCL de 45.000 g·mol -1 al 20% en acetona, ácido acético 1:1, se logra obtener el mayor porcentaje de nanofibras de todos los experimentos, 77% con un diámetro promedio de 88 nm aproximadamente.

Electrospun nanofibers of poly (lactic acid)/poly (ε‐caprolactone) blend for the controlled release of levetiracetam

“…Similar outcomes have been reported in the literature. [62,63] F I G U R E 1 SEM micrographs of (a-d) PLA/LEV10 and (e-h) PLA/PCL/LEV10 ESNF prepared by CHL:DMF solvent system (7:3) and different operation electrospinning conditions: (A, E) voltage = 15 kV and feeding rate = 0.3 ml/h, (B, F) voltage = 15 kV and feeding rate = 0.5 ml/h, (C, G) voltage = 17 kV and feeding rate = 0.5 ml/h, and (D, H) voltage = 19 kV and feeding rate = 0.7 ml/h. tip-to-collector distance for all samples = 18 cm.…”

Polyurethane electrospun membranes with hydroxyapatite‐vancomycin for potential application in bone tissue engineering and drug delivery

“…The Molecular weight was lower, and the molecular weight distribution was broader in PU2 (according to the higher PDI). This is important because, in the electrospinning technique, it is advisable to use polymers with higher molecular weights 31 . Increasing molecular weight reduced the number of beads and droplets 10 …”

Electrospinning of Potential Medical Devices (Wound Dressings, Tissue Engineering Scaffolds, Face Masks) and Their Regulatory Approach

“…The polymer’s molecular weight should also be taken into account. In general, a higher molecular weight is preferable because longer polymer chains facilitate the formation of nanofibers by entangling better [ 28 ]. Furthermore, the diameter of the fibers is also influenced by molecular weight.…”