Dependence of the foaming window of a polystyrene/poly(methyl methacrylate) blend on structural evolution driven by phase separation

Liu, Wei; Pang, Yongyan; Wu, Minghui; Qin, Kangpei; Zheng, Wenge

doi:10.1016/j.polymer.2019.01.050

Cited by 32 publications

(20 citation statements)

References 49 publications

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“…A two-step batch foaming process was applied in this study as it allows for pretreatment of the desired structure before saturation and thus to study the effect of the structure on the foaming behavior. − The PEBA samples treated at the melt state for different times were placed in a high-pressure vessel, and then CO 2 was flushed into the vessel to vent the air. The saturation pressure was set at 4 MPa with a saturation period of 12 h. After the saturation, CO 2 in the vessel was quickly released, and the samples were transferred immediately into a glycerol bath set at different foaming temperatures (i.e., 150, 155, 160, 165, and 170 °C) to foam for 10 s. Finally, the foamed samples were quenched into ice water to solidify the cell structure.…”

Section: Experimental Sectionmentioning

confidence: 99%

Cell Structure Variation in Poly(ether-mb-amide) Copolymer Foams Induced by Chemi-Crystallization

Cao

Pang

Dong

et al. 2020

Ind. Eng. Chem. Res.

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The objective of this study was to clarify the cell structure variation of the poly(ether-mb-amide) (PEBA) copolymer with the chemi-crystallization induced via thermal treatment at the melt state. Thermal annealing was conducted using a compression molding machine at the melt state for various times (i.e., 3, 30, 60, 120, and 300 min) to promote chemi-crystallization. The chemical structure change was studied with Fourier transform infrared spectra, and the viscosity change was investigated using a rheometer. The crystallization behavior was studied with differential scanning calorimetry and X-ray diffraction. The PEBA samples were foamed using a two-step batch foaming process, and the cell structure was investigated with a scanning electron microscope. It was found that the chemical structure of PEBA was hardly changed during the thermal treatment, while the complex viscosity was decreased. It was speculated that degradation occurred probably via a random chain scission mode. Thus, the chemicrystallization was promoted for the crystalline segments because of the less suppression from the noncrystalline segments ascribed to the shorter chains. Consequently, three types of cell structures were observed in PEBA: uniform cell structure, bimodal cell structure, and micro/nanosized cells formed within the spherulites. A scheme was presented to interpret the relationship between the cell structure variation and the crystalline states in PEBA samples. The amorphous, partially melted, and unmelted regions were classified during foaming to interpret the formation of the three types of cell structures.

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Section: Experimental Sectionmentioning

confidence: 99%

Cell Structure Variation in Poly(ether-mb-amide) Copolymer Foams Induced by Chemi-Crystallization

Cao

Pang

Dong

et al. 2020

Ind. Eng. Chem. Res.

Self Cite

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“…This indicated that when the foaming temperature decreased, the dramatically increasing viscosity of CPBAT-3 specimen hindered the cell mergence, the initial morphology of small cells was reserved, which could efficiently reflected the different nucleation types of large cells and small cells (homogeneous and heterogeneous cell nucleation). [58,59] In general, the formed crystals in diverse PBAT specimens played a leading role in the cell nucleation while the viscosity of diverse PBAT specimens played a major part in the cell growth, and the combined action of crystallization and rheology properties of diverse PBAT specimens influenced their final cell morphology. [60][61][62]…”

Section: Cellular Morphology Of Diverse Pbat Foamsmentioning

confidence: 99%

An innovative strategy to regulate bimodal cellular structure in chain extended poly(butylene adipate‐co‐terephthalate) foams

Cui

Zhou

Yin

et al. 2020

Vinyl Additive Technology

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A facile and effective approach for manufacturing poly(butylene adipate‐co‐terephthalate) (PBAT) foams with obvious bimodal cellular structure (BCS) was proposed utilizing chain extension and batch supercritical CO2 foaming technology. Ethylene‐glycidyl methacrylate copolymer (EGMA) as crystalline chain extender was selected to modify PBAT. The results of torque tests, differential scanning calorimetry, and rheological performances demonstrated that the melt strength, viscoelasticity, and crystallization properties of PBAT were improved after introducing EGMA. The influences of EGMA content and foaming temperature on the cellular structure of PBAT foams were investigated systematically. By decreasing the foaming temperature, the size of both large and small cells in the bimodal chain extended PBAT‐3 (CPBAT‐3) foams decreased, as well as their BCS became distinct gradually. The BCS in diverse CPBAT foams was successfully controlled via varying EGMA content and foaming temperature. Finally, the formation mechanism of BCS in diverse PBAT foams was presented.

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“…Polymer foams, one of the innovative materials with remarkable functionality performances, have become more widely used in numerous fields owing to their outstanding advantages including lower thermal conductivity, dielectric constant, good mechanical performance, and low cost. [1][2][3][4][5][6] Recently, polymer foams have drawn enormous industrial and academic interests, which play a significant role in plenty of fields such as packaging materials, thermal and electrical insulators, auto parts, and aerospace industries. [7][8][9] Polypropylene (PP) is one of the most widely used thermoplastics in multifarious areas consisting of domestic appliance, daily necessity, and electronics, in view of its high heat distortion temperature, good tensile and yield strength, excellent stiffness, and super chemical resistance.…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Thermoplastic polyurethane (TPU) modifier to develop bimodal cell structure in polypropylene/TPUmicrocellular foam in presence of supercriticalCO₂

Wang

et al. 2020

Vinyl Additive Technology

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Currently, the fabrication of microcell and bimodal cell structures (BCS) in polymer foams by using supercritical fluids has become a hot as well as a challenging research area worldwide. In this work, an environmentally friendly, effective, facile, and CO 2-based foaming technique was presented to fabricate microcellular polypropylene (PP) foams with BCS via blending with thermoplastic polyurethane (TPU). The toughness, thermal properties, rheological properties, and foamability of PP were systematically investigated with gradual incorporation of TPU. Representative sea-island structure was observed in the scanning electron microscopy (SEM) images for the fracture surface of various PP/TPU samples. Rheological measurement results demonstrated that the viscoelasticity of various PP/TPU samples was improved remarkably compared with that of pure PP and pure TPU. The impact strength of various PP/TPU samples possessed the highest value as 12.4 kJ/m 2 with the TPU content of 15 wt%. After the addition of TPU, an ameliorative cellular morphology was observed in the SEM micrographs of various PP/TPU samples and their volume expansion ratio was enhanced significantly thanks to their improved melt elasticity. Moreover, it is worth noting that BCS appeared in various PP/TPU foams when the TPU content exceeded 5 wt%.

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Dependence of the foaming window of a polystyrene/poly(methyl methacrylate) blend on structural evolution driven by phase separation

Cited by 32 publications

References 49 publications

Cell Structure Variation in Poly(ether-mb-amide) Copolymer Foams Induced by Chemi-Crystallization

Cell Structure Variation in Poly(ether-mb-amide) Copolymer Foams Induced by Chemi-Crystallization

An innovative strategy to regulate bimodal cellular structure in chain extended poly(butylene adipate‐co‐terephthalate) foams

Thermoplastic polyurethane (TPU) modifier to develop bimodal cell structure in polypropylene/TPUmicrocellular foam in presence of supercriticalCO₂

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Dependence of the foaming window of a polystyrene/poly(methyl methacrylate) blend on structural evolution driven by phase separation

Cited by 32 publications

References 49 publications

Cell Structure Variation in Poly(ether-mb-amide) Copolymer Foams Induced by Chemi-Crystallization

Cell Structure Variation in Poly(ether-mb-amide) Copolymer Foams Induced by Chemi-Crystallization

An innovative strategy to regulate bimodal cellular structure in chain extended poly(butylene adipate‐co‐terephthalate) foams

Thermoplastic polyurethane (TPU) modifier to develop bimodal cell structure in polypropylene/TPUmicrocellular foam in presence of supercriticalCO2

Contact Info

Product

Resources

About

Thermoplastic polyurethane (TPU) modifier to develop bimodal cell structure in polypropylene/TPUmicrocellular foam in presence of supercriticalCO₂