A green method to fabricate porous polypropylene fibers: development toward textile products and mechanical evaluation

Abstract

In this study, a series of immiscible polymer blend fibers with polypropylene (PP) and polyvinyl alcohol (PVA) was obtained by a melt spinning process, and two different draw ratios were attempted. Efforts were made to obtain the porous PP fibers by removing the water-soluble PVA phase. The thermal properties of the blends were tested by thermogravimetric analysis and differential scanning calorimetry. The blends showed excellent thermal stability and differentiated fractionated crystallization behaviors of PP. The melt flow indexes of the blends were evaluated, exhibiting a higher fluidity than that of the neat polymers. Among the possible candidates for the spinning process, only the PP70–PVA30 had suitable spinnability, for which the draw ratio reached 3. The morphology of the fibers was investigated by selective extraction experiment and scanning electron microscopy, as well as wide-angle X-ray diffraction. The biphasic morphology and the crystallization behaviors varied according to the PVA content. Furthermore, the mechanical properties of the multifilament fibers were studied via tensile testing and dynamical mechanical analysis. The 70/30 weight ratio (PP/PVA) was the most suitable for producing biphasic fibers with a high degree of accessibility in PVA and mechanical properties that increase with the increase in the drawing ratio. The feasibility of fabric knitting was checked, and the mechanical properties and air permeability of the obtained textile structure were also evaluated.

Surface Structured Polymer Blend Fibers and Their Application in Fiber Reinforced Composite

“…Therefore, the PS phase can act as a model to build microstructure by controlling the shape of PS domains; see the schematic graph in Figure 5 . The spherical and fibril-like bulge structures, grooves [ 15 ], and bundle-like microfiber structure [ 17 ] could be generated on the fiber surface. Usually, these kind of surface-structured fibers are produced by wet-spun [ 44 ], electrospun [ 45 ], how drawing [ 46 ] processes.…”

“…Bump structures are observed on the fiber surface due to the rheological behaviors of dispersed phases under the parabolic flow field during melt-spinning, and (sub) micron grooves are observed on the fiber surface after dissolving the second domains. A similar method had been used to fabricate porous structure in PP fibers by selective extraction of Poly (vinyl alcohol) (PVA) from PP/PVA blend fibers [ 17 ].…”

Porous Fiber Processing and Manufacturing for Energy Storage Applications

“…It is found that enhanced moisture absorption and air permeability of polyamide (PA) fibers can be achieved due to the high solubility of PEG in water. In the research work performed by Yan et al [62], an immiscible polymer blend with polypropylene (PP) and polyvinyl alcohol (PVA) was made and melt spun into fibers. The porous PP fibers were obtained by taking the water-soluble PVA phase away.…”

“…The molten polymer blends were pumped and pushed through two parallel dies with multiple cylindrical holes. A relatively high portion of PVA was removal from the fibers [62,63]. It is noted that other sacrificial polymers may be used to generate the pores.…”

Preparation and structural control of polyphenylene sulfide porous fibers via thermally induced phase separation method

“…In Yan's study, a series of immiscible polymer blend fibers with polypropylene (PP) and polyvinyl alcohol (PVA) were obtained by a melt spinning process, and they obtained the porous PP fibers by removing the water-soluble PVA phase. 21 Compared with the traditional method, such as, particle removal method, it is relatively more facile and economical. The pore structure of the materials can be highly penetrable with significantly improved porosity.…”