Study of the cellular structure heterogeneity and anisotropy of polypropylene and polypropylene nanocomposite foams

2009 ◽  
Vol 49 (12) ◽  
pp. 2400-2413 ◽  
Author(s):  
Marcelo Antunes ◽  
Jose Ignacio Velasco ◽  
Vera Realinho ◽  
Eusebio Solórzano
Keyword(s):  
Cellular Structure ◽  
Nanocomposite Foams ◽  
Structure Heterogeneity

Synthesis and properties of novel polystyrene/polyurea and functional graphene-based nanocomposite foams

2016 ◽  
Vol 53 (3) ◽  
pp. 305-318 ◽  
Author(s):  
Ayesha Kausar
Keyword(s):  
Cellular Structure ◽  
Graphene Layer ◽  
Decomposition Temperature ◽  
Absorption Capacity ◽  
Water Absorption Capacity ◽  
Diphenylmethane Diisocyanate ◽  
Intrinsic Properties ◽  
Simple Route ◽  
Nanocomposite Foams ◽  
Properties Of Materials

A simple route has been adopted for the fabrication of polyurea using polycondensation of 4,4'-diphenylmethane diisocyanate and 1,4-phenylene diamine. Amalgamation of polystyrene, polyurea and functional graphene (F–G) yielded a series of nanocomposite foams. The morphological, electrical, mechanical, thermal, and flammability properties of materials were investigated and found to be dependent upon the intrinsic properties of graphene-based materials and their state of dispersion in matrix. Field emission scanning electron microscopy revealed a strong interaction between polystyrene/polyurea and functional graphene surface forming unique layered cellular structure. Mechanical results revealed a synergistic interaction between F–G and polystyrene/polyurea matrix providing a shielding mechanism against graphene layer damage during compression. The 10% thermal decomposition temperature of polystyrene/polyurea/F–G 1–5 foams measured was in the range of 432–470℃. UL 94 showed V-1 rating for polystyrene/polyurea foam, while polystyrene/polyurea/F–G 1–5 foams attained V-0 rating. Water absorption capacity was improved steadily with the time and was maximum after 96 h for polystyrene/polyurea/F–G 5 foam (4.53%). Functional graphene also produced excellent electrical conductivity improvement in polystyrene/polyurea/F–G 5 foam (101) relative to polystyrene/polyurea/F–G 1 foam (10−2) and neat polystyrene/polyurea foam materials (10−7).

Synergetic effect of nanoclay and nano-CaCO3 hybrid filler systems on the foaming properties and cellular structure of polystyrene nanocomposite foams using supercritical CO2

2020 ◽  
Vol 39 (5) ◽  
pp. 185-202 ◽  
Author(s):  
Xinghan Lian ◽  
Wenjie Mou ◽  
Tairong Kuang ◽  
Xianhu Liu ◽  
Shuidong Zhang ◽  
...  
Keyword(s):  
Cellular Structure ◽  
High Efficiency ◽  
Cell Structure ◽  
Synergetic Effect ◽  
Cell Diameter ◽  
Foaming Properties ◽  
Electron Microscopic ◽  
Hybrid Filler ◽  
Nanocomposite Foams ◽  
Hybrid Fillers

Supercritical fluids have been widely used to prepare various polymer nanocomposite foams due to their high-efficiency, rich-resource, and environment-friendly characteristics. In this work, we prepared polystyrene (PS) nanocomposites with different contents of hybrid fillers of nanoclay and nano-calcium carbonate (nano-CaCO3) and then were foamed by batch foaming method using supercritical carbon dioxide as a physical blowing agent. The effect of hybrid nanofillers components and foaming temperature and pressure on the foaming properties and cellular structure of PS nanocomposite foams was systematically investigated. Dynamic rheology results indicated that the complex viscosity and storage modulus were enhanced with the addition of hybrid fillers. Scanning electron microscopic images show that all samples foamed uniformly macrocells under the given conditions. More importantly, the hybrid fillers of nano-CaCO3 and nanoclay exhibit a significant synergistic effect in improving PS foaming properties, which can be ascribed to the different roles of the two fillers during cell nucleation and cell growth. For instance, the PS/0.22/0.88 nanocomposite foamed under the conditions of 20 MPa and 130°C has shown the finest cell structure (higher cell density of 1.91 × 1010 and smaller cell diameter of 2.28 µm) due to the coeffect of the hybrid nanofillers. Finally, the synergistic mechanism of these two nanofillers on PS foaming behavior was discussed.

Effect of dispersion capability of organoclay on cellular structure and physical properties of PMMA/clay nanocomposite foams

2009 ◽  
Vol 115 (2-3) ◽  
pp. 744-750 ◽  
Author(s):  
Jui-Ming Yeh ◽  
Kung-Chin Chang ◽  
Chih-Wei Peng ◽  
Mei-Chun Lai ◽  
Chih-Bing Hung ◽  
...  
Keyword(s):  
Physical Properties ◽  
Cellular Structure ◽  
Nanocomposite Foams

scholarly journals The Effect of Microcellular Structure on the Dynamic Mechanical Thermal Properties of High-Performance Nanocomposite Foams Made of Graphene Nanoplatelets-Filled Polysulfone

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 437
Author(s):  
Marcelo Antunes ◽  
Hooman Abbasi ◽  
José Ignacio Velasco
Keyword(s):  
Relative Density ◽  
Supercritical Co2 ◽  
Cellular Structure ◽  
High Performance ◽  
Graphene Nanoplatelets ◽  
Cellular Structures ◽  
Density Range ◽  
Specific Storage ◽  
Glass Transition Temperatures ◽  
Nanocomposite Foams

Polysulfone nanocomposite foams containing variable amounts of graphene nanoplatelets (0–10 wt%) were prepared by water vapor-induced phase separation (WVIPS) and supercritical CO2 (scCO2) dissolution. WVIPS foams with two ranges of relative densities were considered, namely, between 0.23 and 0.41 and between 0.34 and 0.46. Foams prepared by scCO2 dissolution (0.0–2.0 wt% GnP) were obtained with a relative density range between 0.35 and 0.45. Although the addition of GnP affected the cellular structure of all foams, they had a bigger influence in WVIPS foams. The storage modulus increased for all foams with increasing relative density and GnP’s concentration, except for WVIPS PSU-GnP foams, as they developed open/interconnected cellular structures during foaming. Comparatively, foams prepared by scCO2 dissolution showed higher specific storage moduli than similar WVIPS foams (same relative density and GnP content), explained by the microcellular structure of scCO2 foams. As a result of the plasticizing effect of CO2, PSU foams prepared by scCO2 showed lower glass transition temperatures than WVIPS foams, with the two series of these foams displaying decreasing values with incrementing the amount of GnP.

scholarly journals Foaming Behaviour, Structure, and Properties of Polypropylene Nanocomposites Foams

2010 ◽  
Vol 2010 ◽  
pp. 1-11 ◽  
Author(s):  
M. Antunes ◽  
V. Realinho ◽  
J. I. Velasco
Keyword(s):  
Electrical Conductivity ◽  
Cellular Structure ◽  
Structure And Properties ◽  
Reinforcement Effect ◽  
Specific Storage ◽  
Structure And Morphology ◽  
Nanocomposite Foams ◽  
Polypropylene Nanocomposites ◽  
Carbon Nanofibre

This work presents the preparation and characterization of compression-moulded montmorillonite and carbon nanofibre-polypropylene foams. The influence of these nanofillers on the foaming behaviour was analyzed in terms of the foaming parameters and final cellular structure and morphology of the foams. Both nanofillers induced the formation of a more isometric-like cellular structure in the foams, mainly observed for the MMT-filled nanocomposite foams. Alongside their crystalline characteristics, the nanocomposite foams were also characterized and compared with the unfilled ones regarding their dynamic-mechanical thermal behaviour. The nanocomposite foams showed higher specific storage moduli due to the reinforcement effect of the nanofillers and higher cell density isometric cellular structure. Particularly, the carbon nanofibre foams showed an increasingly higher electrical conductivity with increasing the amount of nanofibres, thus showing promising results as to produce electrically improved lightweight materials for applications such as electrostatic painting.

scholarly journals Effects of Graphene Nanoplatelets and Cellular Structure on the Thermal Conductivity of Polysulfone Nanocomposite Foams

Polymers ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 25 ◽  
Author(s):  
Hooman Abbasi ◽  
Marcelo Antunes ◽  
José Ignacio Velasco
Keyword(s):  
Thermal Conductivity ◽  
Relative Density ◽  
Supercritical Co2 ◽  
Cellular Structure ◽  
Graphene Nanoplatelets ◽  
Nanocomposite Foams ◽  
Increasing Trend ◽  
The Impact ◽  
Opening Up ◽  
Enhanced Thermal Conductivity

Polysulfone (PSU) foams containing 0–10 wt% graphene nanoplatelets (GnP) were prepared using two foaming methods. Alongside the analysis of the cellular structure, their thermal conductivity was measured and analyzed. The results showed that the presence of GnP can affect the cellular structure of the foams prepared by both water vapor induced phase separation (WVIPS) and supercritical CO2 (scCO2) dissolution; however, the impact is greater in the case of foams prepared by WVIPS. In terms of thermal conductivity, the analysis showed an increasing trend by incrementing the amount of GnP and increasing relative density, with the tortuosity of the cellular structure, dependent on the used foaming method, relative density, and amount of GnP, playing a key role in the final value of thermal conductivity. The combination of all these factors showed the possibility of preparing PSU-GnP foams with enhanced thermal conductivity at lower GnP amount by carefully controlling the cellular structure and relative density, opening up their use in lightweight heat dissipators.

Effect of Organic Montmorillonite on the Cellular Structure and Mechanical Properties of POE/EVA/OMMT Nanocomposite Foams

2013 ◽  
Vol 641-642 ◽  
pp. 355-362 ◽  
Author(s):  
Fu Quan Deng ◽  
Jian Zhong Ma ◽  
Chao Hua Xue ◽  
Zhou Yang Duan
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Cellular Structure ◽  
Ethylene Vinyl Acetate ◽  
Organic Montmorillonite ◽  
Nanocomposite Foams ◽  
Cellular Microstructure ◽  
Ethylene Octene Copolymer ◽  
Eva Copolymer ◽  
Scanning Electron

Nanocomposite foams based-on ethylene octene copolymer (POE)/ethylene vinyl acetate (EVA) copolymer were prepared by melting of POE/EVA with organic montmorillonite (OMMT) by pressurized curing at high temperature. The cellular microstructure of the foamed samples was observed by scanning electron microscope. The effects of OMMT on the cellular structure and mechanical properties of the POE/EVA/OMMT nanocomposite foams were investigated. It was found that OMMT played an important role in affecting the microstructure. Comparing with POE/EVA foam the nanocomposite foams with the addition of 1-3 phr OMMT showed smaller cell size and the structure uniformity of foams was improved. The density of POE/EVA/OMMT nanocomposite samples was lower obviously, meanwhile the mechanical properties of the foamed samples was enhanced.

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