Morphology, structure, and properties of poly(lactic acid) microporous films containing poly(butylene terephthalate) fine fibers fabricated by biaxial stretching

Abstract

The effects of size and shape, i.e., sphere and fiber, of dispersed poly(butylene terephthalate) (PBT) in poly(lactic acid) (PLA) matrix on the morphology and porous structure of the biaxially stretched films are comparatively investigated. Scanning electron microscope results confirm that the PBT fine fibers can be produced by melt-stretching following by fast quenching. Rheological characterization reveals the random network structure of PBT fibers. Further, the stretched films composed of spherical PBT particles show the ellipsoidal microvoids due to the interfacial debonding, and the void size relates to the particle size of PBT. However, size of PBT droplets does not influence the void content of the stretched films. The void content considerably increases for equibiaxial deformation as compared with planar deformation, particularly at high draw ratio. Additionally, the stretched films containing fibrous dispersion exhibit the nonaffine behavior and the highest void content of 8%, which is probably due to the localized deformation between fibers.

Effects of size and shape of dispersed poly(butylene terephthalate) on isothermal crystallization kinetics and morphology of poly(lactic acid) blends

“…Furthermore, PBT spheres were transformed into PBT fibers upon capillary extrusion and subsequent melt stretching, as evidenced by SEM micrographs in Figure 1f2h. The fibrillation occurs when the applied shear stress from a capillary rheometer is greater than the interfacial stress, and the deformed particles are considerably elongated into fibers during extensional flow at the die entry [6]. As expected, the diameter of PBT fiber directly corresponds to the original diameter of PBT sphere in the blends before melt stretching.…”

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Hydrophobic Fibrous Membranes with Tunable Porous Structure for Equilibrium of Breathable and Waterproof Performance

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Electrospun waterproof breathable membrane with a high level of aerosol filtration

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