Polypropylene/Poly(vinyl alcohol) Blends Compatibilized with Kaolinite Janus Hybrid Particles and Their Transformation into Fibers

Abstract

This study focuses on the adoption of hybrid Janus kaolinite particles into immiscible PP−PVA blends for melt spinning, as an extension for the textile field. The anisotropic grafting of kaolinite by octadecylphosphonic acid allowed the localization of the particles at the PP−PVA interface. Then surfacemodified PP porous fibers have been obtained by selective extraction of the PVA phase. The SEM observations and selective extraction experiments indicated that the unmodified kaolinite particles were localized within the PVA phase having limited impact on the PVA accessibility, while Janus-modified particles were distributed at the biphasic interface decreasing significantly the PVA accessibility. The volume average diameter of PVA within annealed blends is dramatically decreased from 73.3 to 13.6 μm by the addition of 5 wt % of Janus kaolinite particles, proving the strong compatibility effect. Gel-like behavior was also observed in rheological investigations for blends filled with modified kaolinite. The melt flow index (MFI) was tested for adapting the conditions of melt spinning. The PVA accessibility can reach more than 90%, and the interface-located fillers can enhance the Young's modulus of the biphasic fibers with 57% increment. The crystallization structure of the porous PP fibers was also influenced by the Janus kaolinite particles, with the enhancement of crystal perfection.

Kinetic and thermodynamic parameters guiding the localization of regioselectively modified kaolin platelets into a PS/PA6 co-continuous blend

“…This natural asymmetric structure involves a difference of reactivity which allows a selective modification of kaolinite with appropriate molecules or polymers [32]. The anisotropic chemical functionalization of kaolin (due to natural asymmetric structure) will allow segregating the platelets at the interface [33]. Three kinds of structures for the grafting agent were tested: a structure bearing several phosphonic acid functions along the polymer chain, a polystyrene structure with only one trialkoxysilane function at the end of the chain and a structure bearing several trialkoxysilane functions along the polymer chain.…”

Porous Fiber Processing and Manufacturing for Energy Storage Applications

“…Porous fibers decorated with nanofillers at surface can also be made using the melt spinning method. As shown by Yan et al [63], the multiphase polypropylene (PP)-polyvinyl alcohol (PVA) fibers containing silica nanoparticles were melt-spun. The fibers has varied surface hydrophobicity.…”

“…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.…”

Heat-regulating polylactic acid/silica aerogel composite fabric: Preparation and characterization

“…As global demand for textiles grows, the potential environmental effects resulting from their production, use, and disposal increase accordingly [1][2][3]. Textile fibers are primarily made from petrochemical materials, such as polyethylene terephthalate (PET) [4], nylon [5], and polypropylene [6]. Unused textile fibers are typically incinerated, which contributes to environmental pollution [7,8].…”