Laser-Assisted Melt Electrospinning of Poly(L-lactide-co-ε-caprolactone): Analyses on Processing Behavior and Characteristics of Prepared Fibers

Abstract

The laser-assisted melt electrospinning (LES) method was utilized for the preparation of poly(L-lactide-co-ε-caprolactone) (PLCL) fibers. During the process, a carbon dioxide laser was irradiated, and voltage was applied to the raw fiber of PLCL. In situ observation of fiber formation behavior revealed that only a single jet was formed from the swelling region under the conditions of low laser power and applied voltage and feeding rate, whereas multiple jets and shots were produced with increases in these parameters. The formation of multiple jets resulted in the preparation of thinner fibers, and under the optimum condition, an average fiber diameter of 0.77 μm and its coefficient of variation of 17% was achieved without the formation of shots. The estimation of tension and stress profiles in the spin-line was also carried out based on the result of in situ observation and the consideration that the forces originated from surface tension, electricity, air friction, and inertia. The higher peak values of tension and stress appearing near the apex of the swelling region corresponded to the formation of thinner fibers for the condition of single-jet ejection. Analyses of the molecular orientation and crystallization of as-spun fibers revealed the formation of a wide variation of higher order structure depending on the spinning conditions.

Progress of biodegradable polymer application in cardiac occluders

“…PLCL, a copolymer of PLLA and PCL, 169 is an aliphatic polyester widely used in scaffolds, vascular grafts, drug delivery, and tissue engineering due to its favorable biocompatibility, elasticity, flexibility, tailorable mechanical properties, and adjustable degradation rate according to PCL/PLLA ratio. [170][171][172][173] In vivo, PLCL degrades into lactic acid and 6-hydroxycaproic acid, which are metabolized and eliminated from the body as hydroxy acids or CO 2 and H 2 O with low tissue reactivity. 174,175 The in vivo degradation process of cardiac occluders typically took 6 to 12 months, 176,177 which is relatively optimal.…”

Thermal Effects on Mechanical Strength of Additive Manufactured CFRP Composites at Stable and Cyclic Temperature

“…The technological advancement in additive manufacturing (AM) over the last decade has been a major driver for the development of composite materials. It is widely known that AM technologies, specifically the fused deposition modeling (FDM) method, have numerous benefits owing to the low price, flexibility, and simplicity with small amounts of waste material, which indeed open up endless possibilities in their utilization in engineering and industrial fields [ 1 , 2 , 3 ]. Carbon-fiber-reinforced polymer (CFRP) has potential applications in the industrial field such as automotive bumper brackets [ 4 ] and the development of more durable wind turbines [ 5 ].…”