Analysis of the polarization state of melt-spun polypropylene fibers

Kravtsov, A. G.; Brünig, Harald; Zhandarov, Serge

doi:10.1016/s0924-0136(02)00129-2

Cited by 16 publications

(6 citation statements)

References 7 publications

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“…During corona treatment charges are injected into the polymer using high electric fields and elevated temperatures. These particular processing conditions may induce several phenomena including such as: (1) trapping of charge carriers by various structural defects in the polymer such as impurities, voids, end groups as well as the interfaces between the crystalline and the amorphous regions, (2) self‐trapping of electrons in the polymer when high energy electrons generates structural defects and get trapped in it, (3) thermal destruction of the polymer, resulting in formation of polar groups and charged molecular fragments, (4) formation of ozone or nitrogen oxides in the air gap under the action of an electric field, followed by macromolecular oxidation and polar group formation and (5) breakage of chemical bonds in the polymer (Kravtsov and Brunig, 2000; Kravtsov et al, 2002).…”

Section: Resultsmentioning

confidence: 99%

Direct probing of solvent‐induced charge degradation in polypropylene electret fibres via electrostatic force microscopy

Kim

Jasper

Hinestroza

2007

Journal of Microscopy

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Summary Electrostatic force microscopy was used to directly probe solvent‐induced charge degradation in electret filter media. Electrostatic force gradient images of individual polypropylene electret fibres were used to quantify the extent of charge degradation caused by the immersion of the fibres into isopropanol. Electrostatic force gradient images were obtained by monitoring the shifts in phase and frequency between the oscillations of the biased atomic force microscopy (AFM) cantilever and those of the piezoelectric driver. Electrostatic force microscopy measurements were performed using non‐contact scans at a constant tip‐sample separation of 75 nm with varied bias voltages applied to the cantilever. Mathematical expressions, based on the capacitance of the tip‐sample system, were used to model the phase and frequency shifts as functions of the applied bias voltage to the tip and the offset voltage due to the fibre's charge. Quantitative agreement between the experimental data and the simplified model was observed.

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Section: Resultsmentioning

confidence: 99%

Direct probing of solvent‐induced charge degradation in polypropylene electret fibres via electrostatic force microscopy

Kim

Jasper

Hinestroza

2007

Journal of Microscopy

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“…Choosing proper conditions is essential to obtain a uniform fiber extrudate, among which the extrusion temperature is one of the most important factors since it affects the viscosity of the melt. Relatively high extrusion temperature above 200°C was usually applied in previous works for low MFI PP resin to decrease the melt viscosity and the extrusion stress . For high‐MFI PP resin in this study, frequent breakage occurred when the barrel and die temperatures were above 200°C due to the low melt viscosity.…”

Section: Resultsmentioning

confidence: 78%

Melt spinning of high-strength fiber from low-molecular-weight polypropylene

et al. 2015

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Polypropylene (PP) with high melt flow index (MFI) or low molecular weight, although desired in melt spinning for enhanced productivity, is difficult to be spun into highstrength fiber using the standard process where extensive jet stretching is applied. In this work, a processing route involving minimal jet stretch has been explored. A twostage hot drawing procedure in the solid state was found to be suitable for producing high-strength fiber from lowmolecular-weight PP with an ultrahigh MFI of 115 g/10 min. Fibers produced achieve a maximum tensile strength and Young's modulus of approximately 600 MPa and 12 GPa, respectively. The melt temperature of the fiber reached 170.88C, approximately 58C higher than that of the original resin. Wide-angle X-ray diffraction (WAXD) study shows that the stable a-monoclinic crystalline structure is developed during the drawing process. A well-oriented crystalline structure along the fiber axis is generated, having a crystalline orientation factor as high as 0.84. POLYM. ENG. SCI.,

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“…As a large activation energy is needed to release this kind of charges, the surface potential of the electret can maintain for a long time. The activation of the trapped charge can be reflected by the location of current peak in the thermally stimulated discharge (TSD) spectrum, higher temperature corresponds to larger activation energy [33] , [34] , [35] . As for the charged PP filter, the current peak at 148 °C ( Fig.…”

Section: Resultsmentioning

confidence: 99%

Enhancing the filtration efficiency and wearing time of disposable surgical masks using TENG technology

Zhang

Bai

et al. 2021

Nano Energy

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The COVID-19 pandemic has caused an unprecedented human and health crisis. And the shortage of protective equipment, especially the personal protective disposable surgical masks, has been a great challenge. Here, we developed an effective and simple scheme to prolong the lifetime of disposable surgical masks without changing their current structure, which is beneficial to solve the shortage of personal masks. After electrifying the meltblown PP filter by the new-developed single-electrode-based sliding triboelectric nanogenerator (TENG) charge replenishment (NGCR) technology, the processed filter is bipolar charged and has a filtration efficiency beyond 95% for the particulate matter (PM) ranging from PM 0.3 to PM 10.0 . Further, we demonstrate the 80 °C dry heating is an effective decontamination method. This method is compatible with single-electrode-based sliding TENG charge replenishment technology. The 80 °C dry heating and the NGCR technology can make up an effective regeneration procedure for the mask. Even after ten cycles of simulated 4-hour wearing process and such regeneration procedure, the filtration efficiency of the disposable surgical masks PM 0.3 is still higher than 95%.

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Analysis of the polarization state of melt-spun polypropylene fibers

Cited by 16 publications

References 7 publications

Direct probing of solvent‐induced charge degradation in polypropylene electret fibres via electrostatic force microscopy

Direct probing of solvent‐induced charge degradation in polypropylene electret fibres via electrostatic force microscopy

Melt spinning of high-strength fiber from low-molecular-weight polypropylene

Enhancing the filtration efficiency and wearing time of disposable surgical masks using TENG technology

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