Studies on dynamically vulcanized polypropylene (PP)/butadiene styrene block copolymer (SBS) blends: Crystallization and thermal behavior

Saroop, Madhumita; Mathur, G. N.

doi:10.1002/(sici)1097-4628(19990103)71:1<151::aid-app18>3.0.co;2-e

Cited by 26 publications

(24 citation statements)

References 18 publications

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“…[8] Classical examples in literature refer to the dynamic crosslinking of poly(propylene)/EPDM mixtures [9,10] and also BR particles dispersed in a PE matrix could be selectively crosslinked by means of free radical initiator, as reported in literature in the case of SBS/PP blends. [11] In this paper we report the results about the crosslinking reaction in the melt of a semi-crystalline polyethylene (PE) ethylene-vinyl acetate copolymers (EVA) and polyethylene/polybutadiene PE/BR blends with an aim to produce materials with a moderately reduced crystallinity (which possibly preserves the high modulus values) and partially crosslinked amorphous fraction (responsible for the elastic behavior over the yield).…”

Section: Introductionmentioning

confidence: 99%

Modulated Crosslinking of Polyolefins through Radical Processes in the Melt

Passaglia

Coiai

Giordani

et al. 2004

Macro Materials & Eng

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Summary: The possibility to submit a semi‐crystalline polyolefin (or a mixture of different polyolefins) to a phase selective crosslinking process, in order to produce a material with unchanged crystallinity but a partially crosslinked amorphous fraction, has been investigated. The crosslinking process has been performed in the melt in the presence of radical initiators. Three different polymer systems have been considered: a LLDPE sample (an ethylene‐1‐butene 91/9 w/w copolymer), two EVA samples (ethylene‐vinyl acetate copolymers containing a different amount (10 and 15 wt.‐%) of acetate monomer units), and mixtures of LLDPE with polybutadiene (BR) (90/10 w/w). All the reaction products have been characterized by selective solvent extractions to determine the gel content, by analysis with different spectroscopies (IR and NMR) and by viscosity measurements to evaluate changes of the structure and the molecular weight (MW) of the partially crosslinked samples. Finally DSC and DMTA analyses have been used to correlate the variations of the macromolecule structure to the thermo‐mechanical properties and, in the case of the mixtures, TEM analysis has been carried out to gather information about the morphology.TEM micrograph of the partially crosslinked polyethylene/polybutadiene blend 90/10 (w/w).magnified imageTEM micrograph of the partially crosslinked polyethylene/polybutadiene blend 90/10 (w/w).

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Section: Introductionmentioning

confidence: 99%

Modulated Crosslinking of Polyolefins through Radical Processes in the Melt

Passaglia

Coiai

Giordani

et al. 2004

Macro Materials & Eng

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“…[1][2][3][4][5][6][7][8][9] During the last few years, investigations of the melting and crystallization behavior of polypropylene have become a subject of increasing interest. However, its low mechanical properties compared with engineering thermoplastics creates problems in its successful end-use application in various fields.…”

Section: Introductionmentioning

confidence: 99%

Studies of Mechanical and Thermal Properties of Polypropylene/LLDPE-Copolymer Blends and Its Glass Fiber Compositions

Gupta

Saroop

Verma

2004

Polymer-Plastics Technology and Engineering

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The mechanical properties, melting, and crystallization behavior of a series of blends of polypropylene (PP) with varying percentages of linear low density polyethylene (LLDPE) copolymer and different fraction of glass fibers were investigated. In mechanical properties tensile and flexural strength, tensile and flexural modulus tends to decrease with increasing percentage of LLDPE copolymer, while a tremendous increase is observed in elongation at break. However, addition of glass fiber results in an increase in both tensile, flexural REPRINTS strength and modulus, especially at 30% glass fiber, where a manifold increase is observed, thereby, reversing the trend of decrease in the tensile properties on incorporation of elastomer. Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) data reveals the decrease in crystallinity and crystallite size distribution on increasing % of LLDPE copolymer and glass fiber in the unfilled and glass-fiber-filled blend.

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“…However, as can be seen in Table 4, the percentage of crystallinity of the Dicup vulcanized blend decreases with the addition of HVA-2. A cross-linked structure produced under dynamic vulcanization may restrict the spherulitic growth and hence decrease the degree of crystallinity of PP [25] . Here, the reduction of percentage of crystallinity, which leads to the increase of network, was due to the extended crosslinking by HVA-2.…”

Section: Thermal Analysismentioning

confidence: 99%

Properties of Polypropylene (PP)/Ethylene-Propylene Diene Terpolymer (EPDM)/Natural Rubber (NR) Vulcanized Blends: The Effect ofN,N-m-Phenylenebismaleimide (HVA-2) Addition

Halimatuddahliana

Ismail

2008

Polymer-Plastics Technology and Engineering

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This paper discusses process development, tensile properties, morphology, oil resistance, gel content, and thermal properties of polypropylene (PP)/ethylene-propylene diene terpolymer (EPDM)/ natural rubber (NR) vulcanized blends with the addition of N,Nm-phenylenebismaleimide (HVA-2) as a compatibilizer. Blends were prepared in several blend ratios in a Haake Polydrive with temperature and rotor speed of 180 C and 50 rpm, respectively. Results indicated that the combination of dicumyl peroxide (Dicup) with HVA-2 shows high torque development and stabilization torque as compared to the blend with Dicup vulcanization alone. In terms of tensile properties, the combination of Dicup with HVA-2 shows higher tensile strength, tensile modulus (M 100 ), elongation at break, oil resistance, and gel content in all blend ratios compared to similar vulcanized blends with Dicup without HVA-2 addition. Scanning electron microscope (SEM) micrographs of the blends support that the cross-linking and compatibilization occur during the process of the vulcanized blend containing HVA-2. In the case of crystallinity of the blends, the addition of HVA-2 in Dicup vulcanized blend revealed a tendency for the percentage of crystallinity (Xc) to decrease. The addition of HVA-2 in Dicup vulcanization also produced blends with good thermal stability dealing with the so-called coagent bridge formation.

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Studies on dynamically vulcanized polypropylene (PP)/butadiene styrene block copolymer (SBS) blends: Crystallization and thermal behavior

Cited by 26 publications

References 18 publications

Modulated Crosslinking of Polyolefins through Radical Processes in the Melt

Modulated Crosslinking of Polyolefins through Radical Processes in the Melt

Studies of Mechanical and Thermal Properties of Polypropylene/LLDPE-Copolymer Blends and Its Glass Fiber Compositions

Properties of Polypropylene (PP)/Ethylene-Propylene Diene Terpolymer (EPDM)/Natural Rubber (NR) Vulcanized Blends: The Effect ofN,N-m-Phenylenebismaleimide (HVA-2) Addition

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