Polymer Nanocomposite Foams Prepared by Supercritical Fluid Foaming Technology

2002 ◽  
Vol 733 ◽  
Author(s):  
L. James Lee ◽  
Changchun Zeng ◽  
Xiangmin Han ◽  
David L. Tomasko ◽  
Kurt W. Koelling
Keyword(s):  
Cell Size ◽  
Cell Density ◽  
Polymer Nanocomposite ◽  
Extrusion Process ◽  
Clay Nanocomposites ◽  
Good Surface ◽  
Nanocomposite Foams ◽  
Continuous Extrusion ◽  
Foaming Technology ◽  
Reduce Cell Size

AbstractPolystyrene (PS) clay nanocomposites were synthesized and used to prepare foams in both batch and continuous extrusion process. It was found that the addition of a small amount of clay could greatly reduce cell size and increase cell density. Once exfoliated, the nanocomposite foam exhibits the highest cell density and the smallest cell size at the same particle concentration. Exfoliated microcellular nanocomposite foams with good surface quality was successfully produced using supercritical carbon dioxide.

Improvement of Structure and Properties of Nanocomposite Foams Based on Ethylene-Vinyl Acetate (EVA)/Natural Rubber (NR)/Nanoclay: Effect of NR Addition

2015 ◽  
Vol 659 ◽  
pp. 418-422 ◽  
Author(s):  
Juthapat Julyanon ◽  
Azizon Kaesaman ◽  
Tadamoto Sakai ◽  
Natinee Lopattananon
Keyword(s):  
Natural Rubber ◽  
Cell Size ◽  
Cell Density ◽  
Vinyl Acetate ◽  
Elastic Recovery ◽  
Cell Structure ◽  
Ethylene Vinyl Acetate ◽  
Melt Mixing ◽  
Nanocomposite Foams ◽  
Nanocomposite Foam

Nanocomposite foams made of ethylene-vinyl acetate (EVA), natural rubber (NR) and nanoclay were fabricated by mean of melt mixing in an internal mixer, and later foaming using azodicarbonamide through compression molding. Effect of NR addition (10-40 phr) into the EVA nanocomposite foam was studied. Characterizations by using Oscillating disk rheometer, X-ray diffraction (XRD), scanning electron microscopy (SEM) and mechanical tests were performed. The XRD analysis showed that the clay was mainly intercalated by the rubber. The SEM analysis revealed that the EVA/NR nanocomposite foams had closed-cell structures. Foaming EVA/NR/clay with composition of 100/0/5 (phr/phr/phr) led to low cell density and large cell size. The EVA nanocomposite foam also had low tensile strength, low compressive strength and low elastic recovery. However, the foam cell structure, i.e., greater cell density and smaller cell size, was obtained when combined with NR. Moreover, the strength and elastic recovery of the EVA nanocomposite foam were improved when the NR was added, and the improvement level was increased with increasing NR content.

Physico-mechanical properties and cell microstructure of cross-linked PVC/organoclay nanocomposite foams prepared at various processing conditions

2020 ◽  
pp. 089270572097869
Author(s):  
Pezhman Rezaei ◽  
Mostafa Rezaei ◽  
Saeid Talebi ◽  
Amin Babaie
Keyword(s):  
Mechanical Properties ◽  
Size Distribution ◽  
Cell Size ◽  
Cell Density ◽  
Expansion Ratio ◽  
Molding Pressure ◽  
Cell Size Distribution ◽  
Gel Content ◽  
Nanocomposite Foams ◽  
Cloisite 30B

Cross-linked polyvinyl chloride (C-PVC) foams and their nanocomposite foams, containing Cloisite 30B nanoclays were prepared. The effects of compression molding pressure and time on the morphology and mechanical properties of different foams were studied. Increment of molding pressure led to higher apparent density, gel content, cell density, and expansion ratio, and wider cell size distribution, which improved the mechanical properties of the foams. Additionally, with the increasing of molding time, lower cell density and final expansion ratio, narrower cell size distribution, and higher gel content and mechanical properties could be obtained. Moreover, incorporation of Cloisite 30B nanoclay in a PVC matrix not only improved cellular microstructure and mechanical properties but also reduced water uptake ratios of nanocomposite foams.

Controlling bubble density in MWNT/polymer nanocomposite foams by MWNT surface modification

2012 ◽  
Vol 72 (2) ◽  
pp. 190-196 ◽  
Author(s):  
Limeng Chen ◽  
Behic K. Goren ◽  
Rahmi Ozisik ◽  
Linda S. Schadler
Keyword(s):  
Surface Modification ◽  
Polymer Nanocomposite ◽  
Nanocomposite Foams ◽  
Bubble Density

Interfaces in Multiphase Polymers and Nanomedicines

2012 ◽  
Vol 714 ◽  
pp. 211-215 ◽  
Author(s):  
Gergo Patyi ◽  
Zsombor Nagy ◽  
Balazs Vajna ◽  
Peter Anna ◽  
Gyorgy Marosi
Keyword(s):  
Extrusion Process ◽  
Structural Features ◽  
Continuous Extrusion ◽  
Multiphase Composite

Crystalline and amorphous interfaces were formed and modified in multiphase composite and pharmaceutical systems. Nanosize drug of antacid effect was prepared in continuous extrusion process. The structural features were analyzed using (micro-) thermal analytical and (micro-) Raman spectrometric methods combined with chemometric evaluation.

Effects of Continuous Extrusion on Microstructure Evolution and Property Characteristics of Brass Alloy

2011 ◽  
Vol 189-193 ◽  
pp. 2921-2924 ◽  
Author(s):  
Bing Li ◽  
Chun Hai Li ◽  
Xiang Jun Yao ◽  
Bao Yun Song
Keyword(s):  
Dynamic Recrystallization ◽  
Microstructure Evolution ◽  
Mechanical Treatment ◽  
Extrusion Process ◽  
Brass Alloy ◽  
Microstructure And Properties ◽  
Continuous Extrusion ◽  
Extruded Products ◽  
The Right

The continuous extrusion process would refine the microstructure effectively and increase the formability and properties of extrusion products, without preheating and post-mechanical treatment. During the continuous extrusion operation the microstructure of brass alloy significantly influences formability and properties. So the microstructure evolution rules of brass alloy during the whole continuous extrusion process were analyzed, and the hardness changing laws of the extruded brass alloy were also researched in this paper. By observing the microstructure evolution at different regions, the evolution rules of microstructure and properties of the continuous extrusion brass alloy were obtained. It was found that the dynamic recrystallization occurred at the right-angle bending region, which was proved by the hardness evolution of the extruded brass alloy. Therefore, it is feasible to control the properties of the extruded products by concentrating the right-angle bending region. This work gives the researching foundation of low formability materials based on continuous extrusion operation.

scholarly journals Recycling of Titanium Alloy Powders and Swarf through Continuous Extrusion (ConformTM) into Affordable Wire for Additive Manufacturing

Metals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 843
Author(s):  
Sarah A. Smythe ◽  
Ben M. Thomas ◽  
Martin Jackson
Keyword(s):  
Titanium Alloy ◽  
Additive Manufacturing ◽  
Extrusion Process ◽  
Space Applications ◽  
Sustainable Supply Chains ◽  
Important Addition ◽  
Alloyed Titanium ◽  
Titanium Powders ◽  
Continuous Extrusion ◽  
Size And Morphology

Over the last 20 years, there has been growing research and development investment to exploit the benefits of wire deposition additive manufacturing (AM) for the production of near-net shape components in aircraft and space applications. The wire feedstock for these processes is a significant part of the overall process costs, especially for high-value materials such as alloyed titanium. Powders for powder-based AM have tight specifications regarding size and morphology, resulting in a significant amount of waste during the powder production. In the aerospace sector, up to 95% of forged billet can be machined away, and with increasing aircraft orders, stockpiles of such machining swarf are increasing. In this study, the continuous extrusion process—ConformTM—was employed to consolidate waste titanium alloy feedstocks in the forms of gas atomised powder and machining swarf into wire. Samples of wire were further cold-drawn down to 40% reduction, using conventional wiredrawing equipment. As close to 100% of the waste powder can be converted to wire by using the ConformTM process. This technology offers an attractive addition to the circular economy for manufacturers and, with further development, could be an important addition as industries move toward more sustainable supply chains.

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