Nanocellular TPU composite foams achieved by stretch-assisted microcellular foaming with low-pressure gaseous CO2 as blowing agent

2021 ◽  
Vol 53 ◽  
pp. 101708
Author(s):  
Jinchuan Zhao ◽  
Guilong Wang ◽  
Aimin Zhang ◽  
Guoqun Zhao ◽  
Chul B. Park
Keyword(s):  
Low Pressure ◽  
Blowing Agent ◽  
Microcellular Foaming ◽  
Composite Foams

Polymer-Nanoparticle Composite Foams for Energy Harvesting Applications

2017 ◽  
Author(s):  
Joseph R. Nalbach ◽  
Matthew S. Schwenger ◽  
Zachary M. Koleszar ◽  
Kelly Greiser ◽  
David Ozalas ◽  
...  
Keyword(s):  
Citric Acid ◽  
Mechanical Energy ◽  
Electrical Characterization ◽  
Electrical Energy ◽  
Porous Structures ◽  
Human Comfort ◽  
Blowing Agent ◽  
Composite Foams ◽  
Piezoelectric Nanoparticles ◽  
Host Polymer

Throughout the course of one day, the human body goes through numerous mechanical activities. These activities, while usually not very powerful individually, produce an ample amount of energy collectively. This mechanical energy can be harvested into electrical energy via piezoelectricity. Recent research into piezoelectric nanocomposites has yielded techniques to foam the materials into softer, porous structures more suitable for human comfort. This study focuses on using a host polymer polydimethylsiloxane (PDMS) and citric acid to create foams. Citric acid, a common industrial chemical blowing agent (CBA), is used in this project due to its capabilities to produce foams with consistent pore sizes and distribution. These foams, coupled with piezoelectric nanoparticles, are fabricated, analyze, and tested. They are mechanically characterized using tensile testing. Electrical characterization is carried out using an integrated mechanical-electrical testing setup. These foams are lighter, softer, and can produce higher electrical output than non-porous counterparts. We believe that these foams have great potential in upcoming piezoelectric technology.

scholarly journals A Novel Hybrid Foaming Method for Low-Pressure Microcellular Foam Production of Unfilled and Talc-Filled Copolymer Polypropylenes

Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1896 ◽  
Author(s):  
Llewelyn ◽  
Rees ◽  
Griffiths ◽  
Jacobi
Keyword(s):  
Injection Molding ◽  
Mechanical Characteristics ◽  
Low Pressure ◽  
Microcellular Foam ◽  
Foaming Agents ◽  
Blowing Agent ◽  
Weight Saving ◽  
Microcellular Foams ◽  
Foam Injection Molding ◽  
Foam Production

Unfilled and talc-filled Copolymer Polypropylene (PP) samples were produced through low-pressure foam-injection molding (FIM). The foaming stage of the process has been facilitated through a chemical blowing agent (C6H7NaO7 and CaCO3 mixture), a physical blowing agent (supercritical N2) and a novel hybrid foaming (combination of said chemical and physical foaming agents). Three weight-saving levels were produced with the varying foaming methods and compared to conventional injection molding. The unfilled PP foams produced through chemical blowing agent exhibited the strongest mechanical characteristics due to larger skin wall thicknesses, while the weakest were that of the talc-filled PP through the hybrid foaming technique. However, the hybrid foaming produced superior microcellular foams for both PPs due to calcium carbonate (CaCO3) enhancing the nucleation phase.

Thermal Conductivity of Carbon Nanofibre-Polypropylene Composite Foams

2010 ◽  
Vol 297-301 ◽  
pp. 996-1001 ◽  
Author(s):  
Marcelo Antunes ◽  
Vera Realinho ◽  
E. Solórzano ◽  
Miguel A. Rodríguez-Pérez ◽  
Jose A. de Saja ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Expansion Ratio ◽  
Polypropylene Composite ◽  
Compression Moulding ◽  
Carbon Nanofibres ◽  
Blowing Agent ◽  
Transient Plane Source ◽  
Composite Foams ◽  
Polypropylene Nanocomposites ◽  
Carbon Nanofibre

Carbon nanofibre-reinforced polypropylene nanocomposites containing from 5 to 20 wt.% of carbon nanofibres and a chemical blowing agent were melt-compounded and later foamed using compression-moulding. Alongside their foaming behaviour analysis and cellular characterization, foams showing an increasingly finer isometric cellular structure with increasing the amount of nanofibres, their thermal conductivity was determined using the Transient Plane Source Method (TPS). Contrarily to the electrical conductivity, which has previously been shown to rise with increasing the amount of carbon nanofibres [1], the addition of the nanofibres did not significantly alter the thermal conductivity of the PP foams, their value being mainly affected by the relative density, only slight differences being assessed for the higher expansion ratio PP-CNF foams.

Rotomolding of Foamed and Unfoamed GTR-LLDPE Blends: Mechanical, Morphological and Physical Properties

2018 ◽  
Vol 37 (2) ◽  
pp. 55-68 ◽  
Author(s):  
Yao Dou ◽  
Denis Rodrigue
Keyword(s):  
Mechanical Properties ◽  
Morphological Properties ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Linear Low Density Polyethylene ◽  
Simple Method ◽  
Ground Tire Rubber ◽  
Blowing Agent ◽  
Composite Foams ◽  
Complete Set

In this work, a simple method is presented to produce ground tire rubber (GTR) -linear low density polyethylene (LLDPE) compounds and foams via rotational molding. In particular, different GTR concentrations (0 to 50% wt.) were dry-blended with different chemical blowing agent (CBA) content (0 to 1% wt.). From the samples produced, a complete set of characterization was performed in terms of mechanical properties (tensile, flexural and impact), density and morphological properties. The results show that increasing GTR content or CBA content not only decreased both tensile and flexural moduli, but decreased ultimate strength and strain at break. As expected, increasing blowing agent content decreased density. Besides, with respect to impact strength, the value of all samples decreased with the addition of GTR or CBA except for 0.2% wt. CBA of GTR-LLDPE composite foams, which nearly remain at the same level.

scholarly journals Fabrication of Highly Interconnected Poly(ε-caprolactone)/cellulose Nanofiber Composite Foams by Microcellular Foaming and Leaching Processes

ACS Omega ◽  
2021 ◽  
Vol 6 (35) ◽  
pp. 22672-22680
Author(s):  
Jiawei Li ◽  
Hongyao Wang ◽  
Hongfu Zhou ◽  
Jing Jiang ◽  
Xiaofeng Wang ◽  
...  
Keyword(s):  
Cellulose Nanofiber ◽  
Nanofiber Composite ◽  
Microcellular Foaming ◽  
Composite Foams

A Novel Design for Producing Fine-Celled Foams of Plastic/Wood-Fiber Composites

2000 ◽  
Author(s):  
Ghaus M. Rizvi ◽  
Chul B. Park
Keyword(s):  
System Design ◽  
Cell Morphology ◽  
Fiber Composite ◽  
Wood Fiber ◽  
Fiber Composites ◽  
Wood Fibers ◽  
Blowing Agent ◽  
Composite Foams ◽  
Innovative System ◽  
Novel Design

Abstract This paper presents an innovative system design for production of plastic/wood-fiber composite foams based on a chemical blowing agent (CBA). Wood-fiber inherently contains moisture, which adversely affects the foam processing and the resultant cell morphology. To improve the cell morphology, the moisture content in the final foam should be minimized. A novel system design is presented for achieving this goal. Undried wood-fibers were processed together with HDPE, CBA and a coupling agent (CA) in a tandem extrusion system. At the interconnection of the two extruders, a vent was provided to purge the moisture into the atmosphere. HDPE/wood-fiber composite foams were produced on this system and on a single extruder without the vent, for comparison. The cellular morphology and volume expansion ratios of the foamed composites were characterized. The foams produced on the newly developed tandem system exhibited significantly improved cell morphology and surface quality.

Sign in / Sign up

Export Citation Format

Share Document