Preparation of polypropylene (PP) composite foams with high impact strengths by supercritical carbon dioxide and their feasible evaluation for electronic packages

Kuo, Chung‐Wen; Liu, Lung-Chang; Liang, Wen-Chung; Liu, Hsin-Chu; Chen, Chien‐Ming

doi:10.1016/j.compositesb.2015.04.021

Cited by 25 publications

(8 citation statements)

References 30 publications

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“…Over the past years, many researchers have attempted to use scCO 2 as a physical blowing agent for preparing polypropylene (PP) foam owing to its high thermal stability and mechanical properties . Although PP foam is a versatile material, its low melt strength and narrow foaming temperature window restrict the continuous fabrication of PP foams in industrial scale .…”

Section: Introductionmentioning

confidence: 99%

A strategy for the preparation of closed‐cell and crosslinked polypropylene foam by supercritical CO₂ foaming

Yang

Xing

Zhao

et al. 2017

J of Applied Polymer Sci

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We report the preparation of a closed-cell polypropylene (PP) foam material by supercritical carbon dioxide foaming with the assistance of g-ray radiation crosslinking. Styrene-ethylene-butadiene-styrene (SEBS) copolymer was added to PP to enhance radiation crosslinking and nucleation. Radiation effects on the foaming of the PP/SEBS blend with different ratios were investigated. A significant improvement in the foaming of the crosslinked PP/SEBS blend was achieved as compared to pristine PP. The cell density of the crosslinked PP/SEBS foam greatly increased at a dose of 10 kGy and a high closed-cell ratio was obtained. The tensile strength of the crosslinked PP/SEBS foams (10 kGy) was improved from 14 to 20.7 MPa compared to pristine PP foam (0 kGy). In addition, the crosslinked PP/SEBS blend exhibited a wider foaming temperature window (10 8C) as compared to the non-crosslinked ones (4 8C).

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Section: Introductionmentioning

confidence: 99%

A strategy for the preparation of closed‐cell and crosslinked polypropylene foam by supercritical CO₂ foaming

Yang

Xing

Zhao

et al. 2017

J of Applied Polymer Sci

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“…The water absorption decreases as the content of the bicycloalkyl group increases. The lowest water absorption occurs for a copolymerization ratio of 10% [22,23,24].…”

Section: Resultsmentioning

confidence: 99%

Synthesis and Physical Properties of Non-Crystalline Nylon 6 Containing Dimer Acid

Huang

et al. 2019

Polymers

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In this study, a long carbon chain dimer acid is introduced into a nylon 6 structure and is copolymerized with different structural amines to produce amorphous nylon 6 by 4,4′-methylenebis(2-methylcyclohexylamine) (MMCA) in different copolymerization ratios. The effect of different structures and copolymerization ratios on the properties of nylon 6 is determined, along with the thermal properties, crystallinity, water absorption, dynamic mechanical properties, and optical properties. It is found that the melting point and the thermal cracking temperature Td10 of nylon 6 are respectively between 176 °C and 213 °C and 378 °C to 405 °C. The effect of introducing a bicyclohexane group containing a methyl side chain is greater than that of a meta-benzene ring, so COMM (synthesized by Caprolactam (C), dimer oleic acid (OA), and 4,4′-Methylenebis(2-methylcyclohexylamine) (MMCA)) has the lowest melting point, enthalpy, and crystallinity. As the copolymerization ratio increases, its thermal properties decrease. 10% is the lowest crystallinity. The amine structure containing a bicycloalkyl group has lower water absorption and a 10% copolymerization ratio gives the lowest water absorption. It contains the bicycloalkyl group, COM (synthesized by Caprolactam (C), dimer oleic acid (OA) and 4,4′-Methylenebis(cyclohexylamine) (MCA)), which has the highest loss modulus. The lowest loss modulus is noted for a copolymerization ratio of 7% and the value of tan δ increases as the copolymerization ratio increases. The introduction of nylon 6 with the bicycloalkyl groups, COMM and COM, significantly increases transparency. As the copolymerization ratio increases, the transparency increases and the haze decreases. The best optical properties are achieved for 10% copolymerization.

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“…5,6 Promisingly, microcellular foamed iPP has a wide range of potential applications, due to its advantages such as higher deforming temperature, light weight, excellent thermal and sound insulation properties, improved impact strength, as well as cost and energy saving merits, over the other traditional physical or chemical fabricated polymer foams. 4,7–12 However, the weak melt strength of iPP during extrusion or injection foaming processes hinders it to gain high foam quality, accompanying with gas escaping and cell collapse defects, during degassing at a foaming temperature much higher to its nominal melting point. 2,4,11,13–16 Moreover, when iPP is subjected to a batch foaming procedure at relatively lower saturation or foaming temperatures (i.e., much more below to iPP’s nominal melting point), it could not be expanded easily, because of its high crystallinity and rigidity of the matrix, 2,11,17 meanwhile, physical foaming agent such as supercritical CO 2 or N 2 could not be dissolved into the crystallized region, compared to the amorphous domain.…”

Section: Introductionmentioning

confidence: 99%

Synergetic effect of crystal nucleating agent and melt self-enhancement of isotactic polypropylene on its rheological and microcellular foaming properties

Zhang

Wang

Dong

et al. 2020

Journal of Cellular Plastics

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Crystal nucleating agent Bis (3, 4- dimethylbenzylidene) sorbitol (DMDBS) was used to tune the melt strength and microcellular foaming properties of isotactic polypropylene (iPP) in this study. Rheological testing results reveal that the introduction of DMDBS could enhance the storage modulus and complex viscosity of iPP, obviously increase its crystallization onset temperature, compared to its counterparts without DMDBS. The addition of DMDBS could also significantly increase the cell nucleating ability of iPP, due to its large surface, cooperating with a thermal history control treatment. Quite fine microcellular iPP/DMDBS foams were fabricated with relatively small average cell sizes of nano to several micrometers, and cell densities up to 1011∼1012 cells/cm3, using the synergy effect of DMDBS and iPP’s melt self-enhancement. Under a comparatively low re-saturation pressure of 8 to 12 MPa, ideal microcellular foams could be generated, at a temperature zone of 158 to 162°C, which is slightly below to iPP’s original pellets nominal melting point.

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Preparation of polypropylene (PP) composite foams with high impact strengths by supercritical carbon dioxide and their feasible evaluation for electronic packages

Cited by 25 publications

References 30 publications

A strategy for the preparation of closed‐cell and crosslinked polypropylene foam by supercritical CO₂ foaming

A strategy for the preparation of closed‐cell and crosslinked polypropylene foam by supercritical CO₂ foaming

Synthesis and Physical Properties of Non-Crystalline Nylon 6 Containing Dimer Acid

Synergetic effect of crystal nucleating agent and melt self-enhancement of isotactic polypropylene on its rheological and microcellular foaming properties

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Preparation of polypropylene (PP) composite foams with high impact strengths by supercritical carbon dioxide and their feasible evaluation for electronic packages

Cited by 25 publications

References 30 publications

A strategy for the preparation of closed‐cell and crosslinked polypropylene foam by supercritical CO2 foaming

A strategy for the preparation of closed‐cell and crosslinked polypropylene foam by supercritical CO2 foaming

Synthesis and Physical Properties of Non-Crystalline Nylon 6 Containing Dimer Acid

Synergetic effect of crystal nucleating agent and melt self-enhancement of isotactic polypropylene on its rheological and microcellular foaming properties

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Product

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A strategy for the preparation of closed‐cell and crosslinked polypropylene foam by supercritical CO₂ foaming

A strategy for the preparation of closed‐cell and crosslinked polypropylene foam by supercritical CO₂ foaming