Morphology Effects on Space Charge Characteristics of Low Density Polyethylene

Zahn, Zhou; Wang, Wang; Ninghua, Ninghua; Sun, Sun; Qinghua, Qinghua; Liang, Liang; Xidong, Xidong; Guan, Guan; Zhichen, Zhichen

doi:10.1143/jjap.50.017101

Cited by 10 publications

(3 citation statements)

References 29 publications

(38 reference statements)

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“…Increase of crystallinity is caused by the formation of new crystal by the scission of molecular chain in the amorphous under radiation [4,6]. The formation of new crystal increases the interface of crystalamorphous, which will increase the charge trapped as interfacial charge at amorphous-crystalline boundaries [30][31][32]. The charge peak in TSC associated with α relaxation initiated by the macromolecular relaxation, and α relaxation is associated with space charge polarization [17,23].…”

Section: Discussionmentioning

confidence: 99%

The effects of γ-ray on charging behaviour using polyimide

Qin¹,

Tu²,

Tan³

et al. 2018

J. Phys. D: Appl. Phys.

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Insulation material is a key component of electrical equipment in satellites; its electrical properties determine the reliability and lifetime of the whole satellite. High-energy radioactive rays in space affect the molecular structure of the polymeric insulating materials. Under the action of plasma, high energy particles, along with the magnetic fields experienced in orbits, electric charges get injected into and trapped by the insulating material creating distortions in the electric field and even electrostatic discharges. Polyimides have been widely used for insulation in spacecraft. Choosing Co-60 gamma ray with irradiation doses of 1 MGy and 5 MGy to simulate the radiation environment of space, we investigated the effect of radiation on charging behaviour. The thermal stimulated current (TSC) from a high electric field over a wide range of temperatures was measured from which the activation energy was calculated. These results for the two sources show that the percentage increase in total charge was 133.3% and 119.4%. The γ, β 3 , and α charge peaks of specimens after an irradiation dose of 1 MGy rose. In comparison, the β 2 peak of the 5 MGy-dosed specimens was enhanced. Also, there is almost no change in the γ, β 3 , and α peaks. To understand the mechanism behind the TSC changes, the resulting physicochemical characteristics of an irradiated specimen were observed employing various analyses of chemical characteristics (x-ray photoelectron spectroscopy, differential scanning calorimetry and x-ray diffraction). Compared with the non-dosed specimen, the relative content of C-N and the glass transition temperature of the 1 MGy sample decreased, and the crystallinity increased, thus increasing the γ and α peak intensities. Compared with the 1 MGy sample, only the glass transition temperature had risen, thereby enhancing the β peak intensity. With the foregoing, a theoretical base for the selection and modification of insulation materials for spacecraft is provided.

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Section: Discussionmentioning

confidence: 99%

The effects of γ-ray on charging behaviour using polyimide

Qin¹,

Tu²,

Tan³

et al. 2018

J. Phys. D: Appl. Phys.

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“…LDPE as a semi-crystal polymer material is composed of a crystal region and amorphous region. Due to the presence of imperfections in LDPE, such as bending, folding or local arrangement of molecular chains, the interface at crystal/ amorphous region, chain scission, branching and side-chains, carrier traps are formed in the material to localize charge [27].…”

Section: Charge Transport Behaviorsmentioning

confidence: 99%

Charge transport in low density polyethylene based micro/nano-composite with improved thermal conductivity

Gao

Wang

et al. 2019

J. Phys. D: Appl. Phys.

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In this work, effect of nano-sized SiO 2 and micro-sized hexagon boron nitride (h-BN) on charge transport behavior of low-density polyethylene (LDPE) has been investigated. LDPE based micro-nanocomposites samples were prepared through hot-press method by adding 20 nm-SiO 2 and 5 µm-h-BN as the fillers. Isothermal surface potential decay measurement was carried out with sample temperature of 40 °C and relative humidity of 23%-29% to obtain trap depth, carrier mobility and field dependent conductivity, by which the effect of fillers on charge transport manners could be estimated. In addition, thermal conductivity test, scanning electron microscopy and differential scanning calorimetry had been employed to assist the analysis of the filler effect. Test results indicated that the crystal structure of LDPE was changed by the doping of the fillers. With the increase of the micro-and nano-filler content, the trap depth tended to be deeper firstly then became shallower. Both band and hopping transport of charge occurred in the composite, and the carrier mobility was dependent upon the filler content. It is suggested that the addition of the nano-sized SiO 2 and the microsized h-BN particles has an effect to inhibit the charge transport, where a synergistic effect among the nano-sized and the micro-sized particles is expected to modify charge trapping and de-trapping behavior.

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“…Consequently, several basic understandings in the structure–property relationships of LDPE for HVAs have been demonstrated. In addition, previous investigations also highlight the ability of the supramolecular structure of LDPE to alter its properties for HVAs. − Müller and co-workers , reported a supramolecular-structured PE-based single polymer composite (SPC) with reinforced mechanical properties and modified electrical properties by simply loading additive-level HDPE into LDPE. In addition to the adaptability for HVAs, as compared with the conventional polymer/filler and polymer/polymer composites, SPCs show significant superiorities: (1) avoiding the long-term challenge of controlling and optimizing the miscibility between each component to achieve a compatible product, (2) better processability, and (3) good recyclability due to the single chemical composition of SPCs.…”

Section: Introductionmentioning

confidence: 99%

Polyethylene-Based Single Polymer Composites Prepared under Elongational Flow for High-Voltage Applications

Huang

Zhao

2020

Ind. Eng. Chem. Res.

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Recently, polyethylene (PE)-based single polymer composites (SPCs) have been found to be potential candidates for high-voltage applications (HVAs) due to their ability to form supramolecular structures and their recyclabilities. However, a deeper understanding of the controls and evolutions of such a structure is still needed. Herein, by introducing elongational flow into the melt compounding, we could successfully control the structure of polymeric materials and prepared PE-SPCs with additive-level ultrahigh-molecular-weight polyethylene (UHMWPE) for HVAs. The elongational flow-induced multiscale multilevel structure was confirmed and analyzed through X-ray diffraction. Specifically, under elongational flow, we fabricated PE-SPCs with the shish-kebab structure and 2D variated crystal units. The melting behaviors of each sample were studied, and the results indicated an elongational flow-induced cocrystallization phenomenon of low-density polyethylene and UHMWPE during melt processing. Benefiting from the as-formed structure, we obtained PE-SPCs with enhanced mechanical properties and more HVA-adaptable dielectric properties. Particularly, the yield strength, tensile strength, and Young’s modulus of PE-SPC (sample R80) show 42, 23, and 29% enhancement than the virgin PE, respectively. The dielectric constant and dielectric loss of our PE-SPC are determined to be around 2.94 and 2 × 10–4 at 1000 Hz, respectively. Moreover, 10-fold decreases in conductivites in both AC and DC of our PE-SPC are achieved after melt compounding under elongational flow. In conclusion, this work gives a comprehensive understanding of the PE-SPCs’ structure evolution under elongational flow, and the structure–property relationship was also determined. It is believed that this work can promote the development of SPCs for HVAs.

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Morphology Effects on Space Charge Characteristics of Low Density Polyethylene

Cited by 10 publications

References 29 publications

The effects of γ-ray on charging behaviour using polyimide

The effects of γ-ray on charging behaviour using polyimide

Charge transport in low density polyethylene based micro/nano-composite with improved thermal conductivity

Polyethylene-Based Single Polymer Composites Prepared under Elongational Flow for High-Voltage Applications

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