Crystal structure and melting behavior of homo-polypropylene and heterophasic ethylene–propylene copolymer after long time heat treatment

Wang, Qianqian; Zhang, Jun; Chen, Shuangjun; Zhu, Han

doi:10.1016/j.jcrysgro.2012.06.030

Cited by 16 publications

(6 citation statements)

References 33 publications

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“…As reported in literatures, five diffraction peaks in every single curve correspond to the lattice planes (110), (040), (130), (111), and (041), respectively, which are all characteristic of α phase with monoclinic configuration for PP. It can be figured out that the diffraction peak 2θ are in good agreement with reference but the relative intensity of diffraction peak in this study differentiates from that in reference . The relative intensity for lattice plane (111) is significantly reduced and its diffraction peak overlaps with that of (041), which can be attributed to the melt‐blown processing for PP fabrics.…”

Section: Resultssupporting

confidence: 78%

Study on correlation of filtration performance and charge behavior and crystalline structure for melt‐blown polypropylene electret fabrics

Xiao

Gui

Chen

et al. 2015

J of Applied Polymer Sci

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Melt-blown polypropylene (PP) electret fabrics are widely used as air filter media due to the specific mechanism of electrostatic filtering. In this article, two additives, stearate and modified rosin, are doped to PP fabrics during melt-blown process. The filtration performance of doped PP gets improved greatly, with filtration efficiency increased by 6% at room temperature but its temperature stability promoted dramatically. As a result, the filtration efficiency of doped PP still remains above 95% of its initial, whereas that of non-doped PP only remains 58% at 1108C. By XRD characterization the structure modification is observed after doping. The crystallinity increases from 14.17% to 22.64% and 29.62%, respectively. Meanwhile, the crystallite has a smaller size, respectively, 89Å and 86Å as compared to 107Å for non-doping in the direction vertical to lattice plane (110). This demonstrates that additive doping can give rise to larger crystallinity and more fine-grained crystallite. Therefore, doped PP improves its charge storage behavior ascribing to expanding interface between crystallite and amorphous region and then enlarging charge trap density. Furthermore, the effect of additive doping on electret charge storage behavior is investigated by short-circuit TSD, and the filtration performance can be explained relevantly with TSD. A charge storage profile is also adopted to illustrate that the space charge captured by charge traps is in the form of space-charge dipole with the rigidity of crystallite.

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Section: Resultssupporting

confidence: 78%

Study on correlation of filtration performance and charge behavior and crystalline structure for melt‐blown polypropylene electret fabrics

Xiao

Gui

Chen

et al. 2015

J of Applied Polymer Sci

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“…In addition, for all investigated materials, the recrystallization temperatures are in the range of 95 and 115 °C. As described by Wang et al . and Mollova et al ., polymer morphology changes because of chain mobility and isothermal crystallization are strongly temperature dependent.…”

Section: Resultsmentioning

confidence: 92%

Hot air aging behavior of polypropylene random copolymers

Grabmann

Wallner

Maringer

et al. 2018

J of Applied Polymer Sci

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This article deals with the global aging behavior of three polypropylene random copolymer (PP-R) materials with varying primary structure and morphology. Hot air aging experiments at elevated temperatures from 95 to 135 C were carried out using micro-sized specimens with a thickness of 100 μm. Technological and analytical aging indicators were monitored for an exposure time of up to 750 days. Independent of comonomer type (ethylene vs. butylene) and morphology (α vs. β crystal form) a critical molar mass of 300 kg mol −1 was obtained. The consumption of antioxidants was slower for the β-nucleated PP-R grade with finer spherulitic structure. The β-grade outperformed the α-crystal PP-R grades resulting in about 20% higher time-to-embrittlement values.

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“…Four strong wide peaks gradually appear, and enhance with the extension of annealing time from 10 to 30 min. Their 2 θ values are 14.3°, 17.2°, 18.7° and 21.8°, corresponding to the lattice planes (110), (040), (130), (111) and (041), respectively, which are the characteristic diffraction peaks of α crystallite with monoclinic configuration for PP [46, 47]. The relative intensity for lattice plane (111) is significantly reduced and its diffraction peak overlaps with that of (041).…”

Section: Experiments Resultsmentioning

confidence: 99%

Charge trapped mechanism for semi‐crystalline polymer electrets: quasi‐dipole model

Chen

Zhang

Shi

et al. 2020

IET Nanodielectrics

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Crystal structure and melting behavior of homo-polypropylene and heterophasic ethylene–propylene copolymer after long time heat treatment

Cited by 16 publications

References 33 publications

Study on correlation of filtration performance and charge behavior and crystalline structure for melt‐blown polypropylene electret fabrics

Study on correlation of filtration performance and charge behavior and crystalline structure for melt‐blown polypropylene electret fabrics

Hot air aging behavior of polypropylene random copolymers

Charge trapped mechanism for semi‐crystalline polymer electrets: quasi‐dipole model

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