The distinctive nucleation of polystyrene composites with differently shaped carbon-based nanoparticles as nucleating agent in the supercritical CO2 foaming process

2018 ◽  
Vol 67 (11) ◽  
pp. 1488-1501 ◽  
Author(s):  
Wei Xiao ◽  
Xia Liao ◽  
Shaojie Li ◽  
Jian Xiong ◽  
Qi Yang ◽  
...  
Keyword(s):  
Supercritical Co2 ◽  
Nucleating Agent ◽  
Foaming Process ◽  
Carbon Based

Effect of rare earth nucleating agent on supercritical CO2 foaming behavior of block copolymerized polypropylene

2021 ◽  
pp. 026248932110536
Author(s):  
Yun Zhang ◽  
Yadong He ◽  
Chunling Xin ◽  
Yanbin Su
Keyword(s):  
Rare Earth ◽  
Saturation Temperature ◽  
Nucleating Agent ◽  
Expansion Ratio ◽  
Good Effect ◽  
Cell Diameter ◽  
Average Cell ◽  
Foaming Process ◽  
Foaming Temperature ◽  
Crystal Content

The rare earth nucleating agent was used to modify block copolymerized polypropylene (PPB) in foaming process. The results show that the crystallization of PPB and the melting temperature of β-crystal increased gradually with increased β-crystal nucleating agent content. The total crystallinity decreased with amount of addition increasing, and the relative content of β-crystal increased first and then decreased. When β-crystal nucleating agent content was 0.4 wt%, the relative β-crystal content reached the maximum value of 95.27%, and the final crystal grain refinement significantly. The addition of rare earth β-crystal nucleating agent has a good effect on improving the uniformity of foam cells. Under the same content of β-crystal nucleating agent and pressure, the average cell diameter and expansion ratio increased with the saturation temperature increasing. After the foaming temperature reaches 155°C, the expansion ratio began to decrease, which was also consistent with the changed trend of relative β-crystal content. At the same content of temperature and relative β-crystal, as the foaming pressure increased, the cell diameter decreased gradually, and the expansion ratio increased first, and then decreased.

scholarly journals High Performance Attapulgite/Polypyrrole Nanocomposite Reinforced Polystyrene (PS) Foam Based on Supercritical CO2 Foaming

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 985 ◽  
Author(s):  
Yidong Liu ◽  
Lingfeng Jian ◽  
Tianhua Xiao ◽  
Rongtao Liu ◽  
Shun Yi ◽  
...  
Keyword(s):  
Supercritical Co2 ◽  
High Performance ◽  
In Situ Polymerization ◽  
Compression Modulus ◽  
Blowing Agents ◽  
Foaming Process ◽  
Potential Applications ◽  
Polymerization Method ◽  
Low Solubility

CO2 has been regarded as one of the most promising blowing agents for polystyrene (PS) foam due to its non-flammability, low price, nontoxicity, and eco-friendliness. However, the low solubility and fast diffusivity of CO2 in PS hinder its potential applications. In this study, an attapulgite (ATP)/polypyrrole (PPy) nanocomposite was developed using the in situ polymerization method to generate the hierarchical cell texture for the PS foam based on the supercritical CO2 foaming. The results demonstrated that the nanocomposite could act as an efficient CO2 capturer enabling the random release of it during the foaming process. In contrast to the pure PS foam, the ATP/PPy nanocomposite reinforced PS foam is endowed with high cell density (up to 1.9 × 106) and similar thermal conductivity as the neat PS foam, as well as high compression modulus. Therefore, the in situ polymerized ATP/PPy nanocomposite makes supercritical CO2 foaming desired candidate to replace the widely used fluorocarbons and chlorofluorocarbons as PS blowing agents.

Supercritical CO2 deposition and foaming process for fabrication of biopolyester-ZnO bone scaffolds

2017 ◽  
Vol 135 (7) ◽  
pp. 45824 ◽  
Author(s):  
Jasna Ivanovic ◽  
Kurosch Rezwan ◽  
Stephen Kroll
Keyword(s):  
Supercritical Co2 ◽  
Bone Scaffolds ◽  
Foaming Process

Evolution of double crystal melting peak in polypropylene foam assisted by β-nucleating agent and supercritical CO2

2017 ◽  
Vol 135 (12) ◽  
pp. 46007 ◽  
Author(s):  
Kesong Yu ◽  
Hanchuan Jiang ◽  
Hongfu Zhou ◽  
Jianguo Mi ◽  
Yadong He ◽  
...  
Keyword(s):  
Supercritical Co2 ◽  
Nucleating Agent ◽  
Melting Peak ◽  
Double Crystal ◽  
Crystal Melting ◽  
Polypropylene Foam

scholarly journals Analysis of Bubble Growth in Supercritical CO2 Extrusion Foaming Polyethylene Terephthalate Process Based on Dynamic Flow Simulation

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2799
Author(s):  
Shun Yao ◽  
Yichong Chen ◽  
Yijie Ling ◽  
Dongdong Hu ◽  
Zhenhao Xi ◽  
...  
Keyword(s):  
Polyethylene Terephthalate ◽  
Bubble Growth ◽  
Supercritical Co2 ◽  
Flow Simulation ◽  
The Finite Element Method ◽  
Melt Flow ◽  
Dynamic Flow ◽  
Foaming Process ◽  
Dynamic Rheological Properties ◽  
Extrusion Foaming

Bubble growth in the polymer extrusion foaming process occurs under a dynamic melt flow. For non-Newtonian fluids, this work successfully coupled the dynamic melt flow simulation with the bubble growth model to realize bubble growth predictions in an extrusion flow. The initial thermophysical properties and dynamic rheological property distribution at the cross section of the die exit were calculated based on the finite element method. It was found that dynamic rheological properties provided a necessary solution for predicting bubble growth during the supercritical CO2 polyethylene terephthalate (PET) extrusion foaming process. The introduction of initial melt stress could effectively inhibit the rapid growth of bubbles and reduce the stable size of bubbles. However, the initial melt stress was ignored in previous work involving bubble growth predictions because it was not available. The simulation results based on the above theoretical model were consistent with the evolution trends of cell morphology and agreed well with the actual experimental results.

scholarly journals Composite Foams Prepared through Hollow Glass Microspheres Assisted Bubbling

2013 ◽  
Vol 22 (1) ◽  
pp. 096369351302200
Author(s):  
Zhenguo An ◽  
Jingjie Zhang
Keyword(s):  
Heat Insulation ◽  
Cell Structure ◽  
Nucleating Agent ◽  
Glass Microspheres ◽  
Insulation Property ◽  
Hollow Glass Microspheres ◽  
Hollow Glass ◽  
Foaming Process ◽  
Composite Foams ◽  
Ammonium Hydrogen

Composite foamy structures were prepared through hollow glass microspheres (HGM) assisted bubbling of silicone rubber with ammonium hydrogen carbonate as the blowing agent. The presence of HGM not only favoured the foaming process (acted as nucleating agent for the formation of minute bubbles at the initial stage of the bubbling), but also bring heterogeneous close-cell bubbles with stable inorganic shells into the foamy structure, which played an important part in the improvement of the heat insulation property of the product. Compared to the foamy structures without HGM, The composite foamy structures possessed improved heat insulation and sound absorbing properties. This work provides an additional strategy to fabricate composite foams with tailored cell structure and properties.

Dual role of PDMS on improving supercritical CO2 foaming of polypropylene: CO2-philic additive and crystallization nucleating agent

2020 ◽  
Vol 163 ◽  
pp. 104888
Author(s):  
Wei Qiang ◽  
Ling Zhao ◽  
Xiulu Gao ◽  
Tao Liu ◽  
Zhen Liu ◽  
...  
Keyword(s):  
Supercritical Co2 ◽  
Nucleating Agent ◽  
Dual Role
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