Enhanced Morphology-Dependent Tensile Property and Breakdown Strength of Impact Polypropylene Copolymer for Cable Insulation

The decrease in electrical properties caused by the toughening of polypropylene (PP) is a difficult problem for the modification of PP used for cable insulation. In this research, an isotactic PP, a cross-linked polyethylene (XLPE) and two impact PP copolymers (IPCs) with an ethylene–propylene rubber phase content of 15 and 30% were prepared to assess the possibility of IPCs to be used as cable insulating material. The tensile properties and breakdown strength were evaluated, meanwhile, the rubber phase content dependence of the crystalline structure, morphology and trap distribution were also investigated. Results show that IPCs with a 15% rubber phase content (IPC15) can achieve the simultaneous improvement of elongation at break and breakdown strength compared with isotactic PP, which can be attributed to the special crystalline structure. According to the results of differential scanning calorimetry (DSC) and FTIR, it is proposed that the lamella thickness of IPC15 is maximal and some ethylene segments exist in PP crystals of IPC15 as crystalline structure defects, which is responsible for this enhanced breakdown strength. The morphology results reveal that rubber microspheres are found to coexist with spherulites, which can promote the relative sliding among lamellas under external force and further results in the increase in the elongation at break.

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Electron microscopy of crystalline structure in thermotropic random copolymers

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100089585 ◽

1991 ◽

Vol 49 ◽

pp. 1054-1055

Author(s):

Afzana Anwer ◽

S. Eilidh Bedford ◽

Richard J. Spontak ◽

Alan H. Windle

Keyword(s):

Electron Microscopy ◽

Crystalline Structure ◽

Liquid Crystalline ◽

Elevated Temperatures ◽

Random Copolymers ◽

Molecular Characteristics ◽

Scanning Calorimetry ◽

X Ray ◽

Identical Monomer ◽

Periodic Layer

Random copolyesters composed of wholly aromatic monomers such as p-oxybenzoate (B) and 2,6-oxynaphthoate (N) are known to exhibit liquid crystalline characteristics at elevated temperatures and over a broad composition range. Previous studies employing techniques such as X-ray diffractometry (XRD) and differential scanning calorimetry (DSC) have conclusively proven that these thermotropic copolymers can possess a significant crystalline fraction, depending on molecular characteristics and processing history, despite the fact that the copolymer chains possess random intramolecular sequencing. Consequently, the nature of the crystalline structure that develops when these materials are processed in their mesophases and subsequently annealed has recently received considerable attention. A model that has been consistent with all experimental observations involves the Non-Periodic Layer (NPL) crystallite, which occurs when identical monomer sequences enter into register between adjacent chains. The objective of this work is to employ electron microscopy to identify and characterize these crystallites.

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Identification of LDPE Grades Focusing on Specific CH2 Raman Vibration Modes

International Journal of Spectroscopy ◽

10.1155/2013/720598 ◽

2013 ◽

Vol 2013 ◽

pp. 1-6 ◽

Cited By ~ 3

Author(s):

Richard Jumeau ◽

Patrice Bourson ◽

Michel Ferriol ◽

François Lahure ◽

Marc Ponçot ◽

...

Keyword(s):

Differential Scanning Calorimetry ◽

Raman Spectroscopy ◽

Vibrational Spectroscopy ◽

Phenomenological Model ◽

Low Density ◽

Vibration Modes ◽

Scanning Calorimetry ◽

Lamella Thickness ◽

Poly Ethylene

The possibilities of applications of vibrational spectroscopy techniques (Raman spectroscopy) in the analysis and characterization of polymers are more and more used and accurate. In this paper, our purpose is to characterize Low Density Poly(Ethylene) (LDPE) grades by Raman spectroscopy and in particular with CH2 Raman vibration modes. With temperature measurements, we determine different amorphous and crystalline Raman assignments. From these results and on the basis of the evolution of CH2 bending Raman vibration modes, we develop a phenomenological model in correlation with Differential Scanning Calorimetry and in particular with crystalline lamella thickness determination.

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Temperature Dependence of Mechanical, Electrical Properties and Crystal Structure of Polyethylene Blends for Cable Insulation

Materials ◽

10.3390/ma11101922 ◽

2018 ◽

Vol 11 (10) ◽

pp. 1922 ◽

Cited By ~ 11

Author(s):

Lunzhi Li ◽

Lisheng Zhong ◽

Kai Zhang ◽

Jinghui Gao ◽

Man Xu

Keyword(s):

High Temperature ◽

Electrical Properties ◽

Temperature Dependence ◽

Elevated Temperatures ◽

Breakdown Strength ◽

Temperature Stability ◽

Xrd Analysis ◽

Insulation Material ◽

Cable Insulation ◽

Polyethylene Blends

There is a long-standing puzzle concerning whether polyethylene blends are a suitable substitution for cable-insulation-used crosslinking polyethylene (XLPE) especially at elevated temperatures. In this paper, we investigate temperature dependence of mechanical, electrical properties of blends with 70 wt % linear low density polyethylene (LLDPE) and 30 wt % high density polyethylene (HDPE) (abbreviated as 70 L-30 H). Our results show that the dielectric loss of 70 L-30 H is about an order of magnitude lower than XLPE, and the AC breakdown strength is 22% higher than XLPE at 90 °C. Moreover, the dynamic mechanical thermal analysis (DMA) measurement and hot set tests suggest that the blends shows optimal mechanical properties especially at high temperature with considerable temperature stability. Further scanning electron microscope (SEM) observation and X-ray diffraction (XRD) analysis uncover the reason for the excellent high temperature performance and temperature stability, which can be ascribed to the uniform fine-spherulite structure in 70 L-30 H blends with high crystallinity sustaining at high temperature. Therefore, our findings may enable the potential application of the blends as cable insulation material with higher thermal-endurance ability.

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THE PHYSICOCHEMICAL CHARACTERISTICS OF RECYCLED-PLASTIC PELLETS OBTAINED FROM DISPOSABLE FACE MASK WASTES

Jurnal Sains Materi Indonesia ◽

10.17146/jsmi.2021.23.1.6336 ◽

2021 ◽

Vol 23 (1) ◽

pp. 16

Author(s):

Vienna Saraswaty ◽

Rossy Choerun Nissa ◽

Bonita Firdiana ◽

Akbar Hanif Dawam Abdullah

Keyword(s):

Tensile Strength ◽

Physicochemical Characterization ◽

Face Mask ◽

Physicochemical Characteristics ◽

Scanning Calorimetry ◽

Elongation At Break ◽

Ft Ir ◽

The Government ◽

Plastic Pellets

THE PHYSICOCHEMICAL CHARACTERISTICS OF RECYCLED-PLASTIC PELLETS OBTAINED FROM DISPOSABLE FACE MASK WASTES. The government policy to wear a face mask during the COVID-19 pandemic has increased disposable face mask wastes. Thus, to reduce such wastes, it is necessary to evaluate the physicochemical characteristics of disposable face masks wastes before the recycling process and the recycled products. In this study, physicochemical characterization of the 3-ply disposable face masks and the recycled plastic pellets after disinfection using 0.5% v/v sodium hypochlorite were evaluated. A set of parameters including the characterization of surface morphology by a scanning electron microscope (SEM), functional groups properties by a fourier transform infra-red spectroscopy (FT-IR), thermal behavior by a differential scanning calorimetry (DSC), tensile strength and elongation at break were evaluated. The surface morphological of each layer 3-ply disposable face mask showed that the layers were composed of non-woven fibers. The FT-IR evaluation revealed that 3-ply disposable face mask was made from a polypropylene. At the same time, the DSC analysis found that the polypropylene was in the form of homopolymer. The SEM analysis showed that the recycled plastic pellets showed a rough and uneven surface. The FT-IR, tensile strength and elongation at break of the recycled plastic pellets showed similarity with a virgin PP type CP442XP and a recycled PP from secondary recycling PP (COPLAST COMPANY). In summary, recycling 3-ply disposable face mask wastes to become plastic pellets is recommended for handling disposable face mask wastes problem.

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Influence of acrylonitrile butadiene rubber on recyclability of blends prepared from poly(vinyl chloride) and poly(methyl methacrylate)

Waste Management & Research ◽

10.1177/0734242x18771164 ◽

2018 ◽

Vol 36 (6) ◽

pp. 495-504 ◽

Cited By ~ 6

Author(s):

Sunil S Suresh ◽

Smita Mohanty ◽

Sanjay K Nayak

Keyword(s):

Methyl Methacrylate ◽

Vinyl Chloride ◽

Butadiene Rubber ◽

Scanning Calorimetry ◽

Elongation At Break ◽

Poly Methyl Methacrylate ◽

Impact Performance ◽

Acrylonitrile Butadiene Rubber ◽

Poly Vinyl Chloride ◽

Spectroscopy Studies

The current investigation deals with the recycling possibilities of poly(vinyl chloride) and poly(methyl methacrylate) in the presence of acrylonitrile butadiene rubber. Recycled blends of poly(vinyl chloride)/poly(methyl methacrylate) are successfully formed from the plastic constituents, those are recovered from waste computer products. However, lower impact performance of the blend and lower stability of the poly(vinyl chloride) phase in the recycled blend restricts its further usage in industrial purposes. Therefore, effective utilisation acrylonitrile butadiene rubber in a recycled blend was considered for improving mechanical and thermal performance. Incorporation of acrylonitrile butadiene rubber resulted in the improvement in impact performance as well as elongation-at-break of the recycled blend. The optimum impact performance was found in the blend with 9 wt% acrylonitrile butadiene rubber, which shows 363% of enhancement as compared with its parent blend. Moreover, incorporated acrylonitrile butadiene rubber also stabilises the poly(vinyl chloride) phase present in the recycled blend, similarly Fourier transform infrared spectroscopy studies indicate the interactions of various functionalities present in the recycled blend and acrylonitrile butadiene rubber. In addition to this, thermogravimetric analysis indicates the improvement in the thermal stability of the recycled blend after the addition of acrylonitrile butadiene rubber into it. The existence of partial miscibility in the recycled blend was identified using differential scanning calorimetry and scanning electron microscopy.

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Effects of walnut shell powders on the morphology and the thermal and mechanical properties of poly(lactic acid)

Journal of Thermoplastic Composite Materials ◽

10.1177/0892705719828801 ◽

2019 ◽

Vol 33 (10) ◽

pp. 1383-1395

Author(s):

Hongjuan Zheng ◽

Zhengqian Sun ◽

Hongjuan Zhang

Keyword(s):

Mechanical Properties ◽

Lactic Acid ◽

Property Testing ◽

Walnut Shell ◽

Poly Lactic Acid ◽

Thermal And Mechanical Properties ◽

Scanning Calorimetry ◽

Elongation At Break ◽

Heat Distortion Temperature ◽

Testing Techniques

Poly(lactic acid) (PLA) has good environmental compatibility, however, its high brittleness, slow rate of crystallization, and low heat distortion temperature restrict its widespread use. To overcome these limitations, in this study, PLA was mixed with walnut shell (WS) powders. The effects of WS powders on the morphology and the thermal and mechanical properties of PLA were investigated. The products were characterized by differential scanning calorimetry (DSC), infrared (IR) spectroscopy, polarizing optical microscopy (POM), and various mechanical property testing techniques. The results showed that WS powders had a significant effect on the morphology and the thermal and mechanical properties of PLA. The tensile strength, impact strength, and elongation at break of the PLA/WS composites first increased and then decreased with the increasing addition of WS powders. When the addition of WS powders was about 0.5 wt%, they reached maximum values of 51.2 MPa, 23.3 MPa, and 19.0%, respectively. Compared with neat PLA, the spherulite grain size of the composites could be reduced and many irregular polygons were formed during crystallization. The melting, cold crystallization, and glass-transition temperatures of the composites were lower than those of neat PLA.

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Characterization of Polypropylene Modified by Blending Elastomer and Nano-Silica

Materials ◽

10.3390/ma11081321 ◽

2018 ◽

Vol 11 (8) ◽

pp. 1321 ◽

Cited By ~ 14

Author(s):

Xiaohong Chi ◽

Lu Cheng ◽

Wenfeng Liu ◽

Xiaohong Zhang ◽

Shengtao Li

Keyword(s):

Dielectric Properties ◽

Space Charge ◽

Power Transmission ◽

Breakdown Strength ◽

Tensile Tests ◽

Mechanical Analysis ◽

Insulation Material ◽

Nano Silica ◽

Scanning Calorimetry ◽

High Voltage Direct Current

Polypropylene (PP) contains promising application prospects in thermoplastic cables for high voltage direct current (HVDC) power transmission because of its outstanding thermal and dielectric properties. However, the problem of poor toughness and space charge has restricted the application of pure PP in HVDC cables. In this paper, polyolefin elastomer (POE) and nano-silica were blended thoroughly and added into a PP mixture by a melting method. Scanning electron microscopy (SEM) was employed to observe the dispersion of POE and nanoparticles. Thermal properties were characterized by differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). Mechanical properties were evaluated by tensile tests. The elastomeric properties of composites were improved as the dispersed POE could transfer and homogenize external mechanical forces. DC breakdown results showed that the fail strength of composite with 10 phr POE and 1 phr nano-silica was obviously enhanced. The pulsed electro-acoustic (PEA) results showed that the injection and accumulation of space charge was increased by the introduction of POE, while it was restrained by the collective effect caused by nano-silica filling. X-ray diffraction (XRD) spectrograms showed that secondary ordered structures existed in the composites of PP, POE, and nano-silica, and that the ordered structure around the nanoparticles contributed to the enhancement of breakdown strength. The mechanical and dielectric properties were modified synergistically, which made the modified PP a propitious insulation material for HVDC cables.

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Micro and nanocomposites of polybutadienebased polyurethane liners with mineral fillers and nanoclay: thermal and mechanical properties

Open Chemistry ◽

10.1515/chem-2017-0006 ◽

2017 ◽

Vol 15 (1) ◽

pp. 46-52 ◽

Cited By ~ 4

Author(s):

Pablo Ross ◽

Germán Escobar ◽

Guillermo Sevilla ◽

Javier Quagliano

Keyword(s):

Thermal Properties ◽

Polymer Chains ◽

Toluene Diisocyanate ◽

Mechanical And Thermal Properties ◽

Scanning Calorimetry ◽

Elongation At Break ◽

Force Microscopy ◽

Atomic Force ◽

Mineral Fillers

AbstractMicro and nanocomposites of hydroxyl terminated polybutadiene (HTPB)-based polyurethanes (NPU) were obtained using five mineral fillers and Cloisite 20A nanoclay, respectively. Samples were prepared by the reaction of HTPB polyol and toluene diisocyanate (TDI), and the chain was further extended with glyceryl monoricinoleate to produce the final elastomeric polyurethanes. Mechanical and thermal properties were studied, showing that mineral fillers (20%w/w) significantly increased tensile strength, in particular nanoclay (at 5% w/w). When nanoclay-polymer dispersion was modified with a silane and hydantoin-bond promoter, elongation at break was significantly increased with respect to NPU with C20A. Thermal properties measured by differential scanning calorimetry (DSC) were not significantly affected in any case. The molecular structure of prepared micro and nanocomposites was confirmed by Fourier transform infrared (FTIR) spectroscopy and Raman spectroscopy. Interaction of fillers with polymer chains is discussed, considering the role of silanes in compatibilization of hydrophilic mineral fillers and hydrophobic polymer. The functionalization of nanoclay with HMDS silane was confirmed using FTIR. Microstructure of NPU with C20A nanoclay was confirmed by Atomic Force Microscopy (AFM).

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Toughening Modification of Poly(butylene terephthalate)/Polycarbonate Blends by Poly(ethylene-co-octene)

Polymers and Polymer Composites ◽

10.1177/096739110501300405 ◽

2005 ◽

Vol 13 (4) ◽

pp. 385-394

Author(s):

Huiyu Bai ◽

Yong Zhang ◽

Yinxi Zhang ◽

Xiangfu Zhang ◽

Wen Zhou

Keyword(s):

Average Diameter ◽

Melt Blending ◽

Screw Extruder ◽

Scanning Calorimetry ◽

Bisphenol A Polycarbonate ◽

Elongation At Break ◽

Butylene Terephthalate ◽

Twin Screw ◽

Poly Ethylene ◽

The Impact

New toughened poly(butylene terephthalate) (PBT)/bisphenol A polycarbonate (PC) blends were obtained by melt blending with commercial poly(ethylene-co-octene) copolymer (POE), varying the POE content up to 10 wt%, in a twin screw extruder, followed by injection moulding. The influence of POE on the properties of the PBT/PC blends was investigated in terms of mechanical testing, dynamic mechanical thermal (DMTA) analysis, differential scanning calorimetry (DSC), and scanning electronic microscopy (SEM). The results showed that addition of POE led to remarkable increases in the impact strength, elongation at break and Vicat temperature, and a reduction in the tensile strength and flexural properties of PBT/PC blends. The morphology of the blends was observed using SEM and the average diameter of the dispersed phase was determined by image analysis. The critical inter-particle distance for PBT/PC was determined.

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Polypropylene/wood powder composites: Evaluation of PP viscosity in thermal, mechanical, thermomechanical, and morphological characters

Journal of Thermoplastic Composite Materials ◽

10.1177/0892705719880958 ◽

2019 ◽

pp. 089270571988095 ◽

Cited By ~ 2

Author(s):

Eduardo da Silva Barbosa Ferreira ◽

Carlos Bruno Barreto Luna ◽

Edcleide Maria Araújo ◽

Danilo Diniz Siqueira ◽

Renate Maria Ramos Wellen

Keyword(s):

Softening Temperature ◽

Morphological Characters ◽

Environmental Benefits ◽

Similar Data ◽

Wood Powder ◽

Scanning Calorimetry ◽

Sem Images ◽

Elongation At Break ◽

Twin Screw ◽

Powder Composites

Large waste amounts from wood industries as powder and sawdust are daily produced, and reusing these materials otherwise would be discharged to the environment has become an economically viable and environmentally friendly alternative to produce new materials. Based on these arguments, polypropylene (PP)/Jatobá wood powder composites upon addition of two types of PP were processed in a corotational twin screw extruder; specimens were injected and molded and their characterization was performed through differential scanning calorimetry, thermogravimetry, mechanical properties (impact, tensile, flexural, and hardness), heat deflection temperature (HDT), Vicat softening temperature, and scanning electron microscopy (SEM). Increased elastic modulus, shore D hardness, HDT, and Vicat related to neat PPs were reached. Nevertheless, losses in impact and tensile strength as well as in elongation at break were also verified. These lower data may be associated with the wood agglomeration, as shown in SEM images. Apparently, the investigated properties were not affected by PP viscosities, where both of them presented similar data. Summing up, presented results can be considered commercially feasible, focusing at economic and environmental benefits while producing higher performance products.

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