Morphology and Properties of Polypropylene Foaming Sheet with Alternating Multilayered Structure

Zhao, Tianbao; Wu, Hong; Guo, Shaoyun; Sun, Xiaoyang; Liang, Wenbin

doi:10.1080/03602559.2014.979499

Cited by 10 publications

(5 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Hence, it would be very hard for the cells to grow from the PS layers, and then, the PS layers became the unfoamed film (Figure b 3 ). The gas dissolved in PS layers would then be used for cell nucleation and growth in PS–SiO 2 layers, as the activation energy for heterogeneous cell nucleation is much lower than that for homogeneous cell nucleation. , However, the film thickness in the alternating film/foam assemblies formed in this study is much thinner compared to those about 20–200 μm in the literature ,− prepared via coextrusion with chemical foaming agents. The preparation approach provided in this study can save more materials and obtain film/foam assemblies of lower densities.…”

Section: Resultsmentioning

confidence: 82%

“…In recent years, multilayered foams have emerged as a new branch of foams that feature alternating layered structures. − Due to the special cell structure, the multilayered foams show excellent mechanical, thermal insulation, and sound absorption properties. Till now, different approaches have been reported about the preparation of multilayered foams.…”

Section: Introductionmentioning

confidence: 99%

“…Till now, different approaches have been reported about the preparation of multilayered foams. The groups of Baer − and Guo − prepared alternating film/foam assemblies via a multilayered coextrusion technique, with the chemical foaming agent incorporated in the alternating layers to decompose during processing. Generally, the same polymer is used for the film layer and the foam layer, but the foams prepared through this approach have cells only in alternating layers, i.e., the foam layers.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Unprecedented Cell Structure Variation in Multilayered Alternating PS/PS–SiO₂ Foams

Pang

Cao

Guo

et al. 2021

ACS Appl. Polym. Mater.

View full text Add to dashboard Cite

The objective of the present work was to report the unprecedented cell structure variation in multilayered alternating polystyrene (PS)/PS−SiO 2 foams. The multilayered alternating PS/PS−SiO 2 foams were prepared via a coextrusion technique and a subsequent batch foaming process with high-pressure carbon dioxide (CO 2 ). The multilayered PS/PS−SiO 2 stacks were controlled of different layers (2, 4, 8, 16, 32, 64, and 128) using the layer-multiplying elements (LMEs). The PS−SiO 2 nanocomposite was prepared using a twin-screw extruder with 99 wt % PS resins and 1 wt % SiO 2 nanoparticles. With the increase of the layer number, three types of cell structures were observed: alternating big-cell/small-cell layers, a single big-cell layer in small-cell layers, and alternating film/small-cell layers. The original big cells were formed in the pure PS layer, and the small ones in the PS−SiO 2 layers. It was considered that the decrease in the thickness of the pure PS layer and the increase in the thickness of the PS−SiO 2 layer due to the interfacial mixing between the adjacent layers is the reason for the unprecedented cell structure variation. A possible mechanism was proposed for interpreting the cell structure variation in the preparation of multilayered PS/PS−SiO 2 foams. The interfacial mixing can be taken as the strategy to tune the cell structures for the purpose of end-use demands in preparing multilayered foams using the same polymer in adjacent layers.

show abstract

Section: Resultsmentioning

confidence: 82%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Unprecedented Cell Structure Variation in Multilayered Alternating PS/PS–SiO₂ Foams

Pang

Cao

Guo

et al. 2021

ACS Appl. Polym. Mater.

View full text Add to dashboard Cite

show abstract

“…However, compared to polyethylene, isotactic polypropylene more easily undergoes degradation upon irradiation, resulting in a poorer resistance to weathering [18,19]. Many studies have been performed on the foaming of PP by scCO2 [20][21][22]. The melt strength and mechanical and heat-resistant properties of polypropylene have been shown to be significantly improved by irradiation in the presence of a cross-linking agent [23].…”

Section: Gel Content and Melt Flow Index Analysesmentioning

confidence: 99%

Supercritical CO2 Foaming of Radiation Cross-Linked Isotactic Polypropylene in the Presence of TAIC

et al. 2016

View full text Add to dashboard Cite

Abstract:Since the maximum foaming temperature window is only about 4 • C for supercritical CO 2 (scCO 2 ) foaming of pristine polypropylene, it is important to raise the melt strength of polypropylene in order to more easily achieve scCO 2 foaming. In this work, radiation cross-linked isotactic polypropylene, assisted by the addition of a polyfunctional monomer (triallylisocyanurate, TAIC), was employed in the scCO 2 foaming process in order to understand the benefits of radiation cross-linking. Due to significantly enhanced melt strength and the decreased degree of crystallinity caused by cross-linking, the scCO 2 foaming behavior of polypropylene was dramatically changed. The cell size distribution, cell diameter, cell density, volume expansion ratio, and foaming rate of radiation-cross-linked polypropylene under different foaming conditions were analyzed and compared. It was found that radiation cross-linking favors the foamability and formation of well-defined cell structures. The optimal absorbed dose with the addition of 2 wt % TAIC was 30 kGy. Additionally, the foaming temperature window was expanded to about 8 • C, making the handling of scCO 2 foaming of isotactic polypropylene much easier.

show abstract

“…The cell nucleation, bubble growth and the final cell morphology of extruded PP foams have been studied extensively (2)(3)(4)(5)(6). Earlier studies attempted to enhance the melt strength by partial crosslinking of PP (7).…”

Section: Introductionmentioning

confidence: 99%

The simultaneous effect of nucleating and blowing agents on the cellular structure of polypropylene foamed via the extrusion process

2016

View full text Add to dashboard Cite

Abstract:The current work presents the preparation of polypropylene (PP) foams by the extrusion process, focusing on the influence of the foaming agent and nucleating agent on the microstructure of the foams. Sodium bicarbonate alone and also its mixture with citric acid were used as the chemical blowing agents. Expanded graphite nanoparticle and talc were also used as the nucleating agents. Great differences were found in terms of the foam structure depending on the type of nucleating and blowing agents. Using expanded graphite nucleating agent instead of talc resulted in foams with higher cell densities and more uniform cellular structures. Moreover, the foams including the mixed blowing agents exhibited higher cell densities and upper expansion ratio.

show abstract

Morphology and Properties of Polypropylene Foaming Sheet with Alternating Multilayered Structure

Cited by 10 publications

References 30 publications

Unprecedented Cell Structure Variation in Multilayered Alternating PS/PS–SiO₂ Foams

Unprecedented Cell Structure Variation in Multilayered Alternating PS/PS–SiO₂ Foams

Supercritical CO2 Foaming of Radiation Cross-Linked Isotactic Polypropylene in the Presence of TAIC

The simultaneous effect of nucleating and blowing agents on the cellular structure of polypropylene foamed via the extrusion process

Contact Info

Product

Resources

About

Morphology and Properties of Polypropylene Foaming Sheet with Alternating Multilayered Structure

Cited by 10 publications

References 30 publications

Unprecedented Cell Structure Variation in Multilayered Alternating PS/PS–SiO2 Foams

Unprecedented Cell Structure Variation in Multilayered Alternating PS/PS–SiO2 Foams

Supercritical CO2 Foaming of Radiation Cross-Linked Isotactic Polypropylene in the Presence of TAIC

The simultaneous effect of nucleating and blowing agents on the cellular structure of polypropylene foamed via the extrusion process

Contact Info

Product

Resources

About

Unprecedented Cell Structure Variation in Multilayered Alternating PS/PS–SiO₂ Foams

Unprecedented Cell Structure Variation in Multilayered Alternating PS/PS–SiO₂ Foams