Cell Structure Evolution and the Crystallization Behavior of Polypropylene/Clay Nanocomposites Foams Blown in Continuous Extrusion

2010 ◽  
Vol 49 (20) ◽  
pp. 9834-9845 ◽  
Author(s):  
Wentao Zhai ◽  
Takashi Kuboki ◽  
Lilac Wang ◽  
Chul B. Park ◽  
Eung K. Lee ◽  
...  
Keyword(s):  
Crystallization Behavior ◽  
Cell Structure ◽  
Structure Evolution ◽  
Clay Nanocomposites ◽  
Continuous Extrusion

scholarly journals Effects of zinc acetate and cucurbit[6]uril on PP composites: crystallization behavior, foaming performance and mechanical properties

e-Polymers ◽  
2018 ◽  
Vol 18 (6) ◽  
pp. 491-499 ◽  
Author(s):  
Yuhui Zhou ◽  
Li He ◽  
Wei Gong
Keyword(s):  
Impact Strength ◽  
Flexural Strength ◽  
Zinc Acetate ◽  
Crystallization Behavior ◽  
Cell Structure ◽  
Weight Ratio ◽  
Crystallization Rate ◽  
Sem Images ◽  
Improvement Effect ◽  
Lower Temperature

AbstractIn this study, polypropylene (PP) foams were prepared with 1.0 wt% of cucurbit[6]uril (Q[6]), zinc acetate (Zn(Ac)2), Zn@Q[6] (a supramolecular compound synthesized from Q[6] and Zn(Ac)2), or a mixture of Zn(Ac)2 and Q[6] (weight ratio of 1:1) through injection molding in the presence of a chemical blowing agent, azodicarbonamide. The effect of the additions on the crystallization behavior and foaming performance of PP and the mechanical characterizations of the foaming samples were determined. The results showed that the additions can change the crystallization type from homogeneous to heterogeneous, increase the crystallization rate and shrink the size but increase the density of spherulites. Among the additions, Q[6] most significantly altered the crystallization properties. Scanning electron microscopy (SEM) images revealed that the PP foaming performance can be improved by Zn(Ac)2 addition at a lower temperature (175°C); however, further increasing the temperature had an undesirable effect. Q[6] exhibited the optimum foaming improvement effect on PP in a wide temperature range (175–195°C). Adding nanoparticles also enhanced the tensile properties, flexural strength and impact strength of foaming PP at low temperatures. However, with increasing temperature, the poor cell structure demonstrated undesirable effects in terms of tensile strength, flexural strength and impact strength.

Investigating the Effect of Nanoclay Loadings and Re-Processing on the Melting and Crystallization Behavior of PP/Clay Nanocomposites

2019 ◽  
Vol 951 ◽  
pp. 21-25
Author(s):  
Achmad Chafidz ◽  
Sholeh Ma'mun ◽  
Haryanto ◽  
Wara Dyah Pita Rengga ◽  
Prima A. Handayani ◽  
...  
Keyword(s):  
Crystallization Behavior ◽  
Crystallization Process ◽  
The Other ◽  
Degree Of Crystallinity ◽  
Clay Nanocomposites ◽  
Scanning Calorimetry ◽  
Onset Crystallization Temperature ◽  
Significant Difference ◽  
The Degree Of Crystallinity ◽  
Melting And Crystallization

In this study, PP/clay nanocomposites have been fabricated at different nanoclay loadings, i.e. 0, 5, 10, and 5 wt% for the 1stcycle and 2ndcycle (re-processing). The prepared nanocomposites were then characterized by a Differential Scanning Calorimetry (DSC) to investigate the effects of nanoclay loadings and re-processing on the melting and crystallization of the nanocomposites. The DSC results showed that the melting temperature,Tmwas not significantly affected by the nanoclay loadings and re-processing. In the other hand, the degree of crystallinity,Xcof the nanocomposites was higher than that of neat PP, but only reached a maximum at nanoclay loading of 5 wt% (i.e. 51.2% for NC-5-I and 48.3% for NC-5-II). Thereafter, theXcdecreased at higher nanoclay loadings. There was no significant difference inXcbetween 1stcycle and 2ndcycle. Additionally, in all nanocomposites samples for both cycles, there were two crystallization temperatures, i.e.Tc1andTc2. In the overall crystallization process, theTcof nanocomposites increased by 11-12°C compared to that of neat PP. Whereas, the onset crystallization temperature,Tocalso increased by approx. 13°C. Apparently, there was no significant effect of nanoclay loadings and re-processing on theTcndTocof the nanocomposites.

Strain-induced crystallization behavior of phenolic resin crosslinked natural rubber/clay nanocomposites

2015 ◽  
Vol 132 (39) ◽  
pp. n/a-n/a ◽  
Author(s):  
Abdulhakim Masa ◽  
Sougo Iimori ◽  
Ryota Saito ◽  
Hiromu Saito ◽  
Tadamoto Sakai ◽  
...  
Keyword(s):  
Natural Rubber ◽  
Crystallization Behavior ◽  
Phenolic Resin ◽  
Clay Nanocomposites ◽  
Strain Induced Crystallization ◽  
Induced Crystallization

New insight into the crystallization behavior of poly(ethylene terephthalate)/clay nanocomposites

2008 ◽  
Vol 46 (21) ◽  
pp. 2380-2394 ◽  
Author(s):  
Guohu Guan ◽  
Chuncheng Li ◽  
Xuepei Yuan ◽  
Yaonan Xiao ◽  
Xiaoqing Liu ◽  
...  
Keyword(s):  
Crystallization Behavior ◽  
Ethylene Terephthalate ◽  
Clay Nanocomposites ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene ◽  
Insight Into

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.

Effect of Plasticizer (DOP) on Cell Structure and Mechanical Properties of Extrusion-Foamed PVC Sheet

2015 ◽  
Vol 815 ◽  
pp. 601-606 ◽  
Author(s):  
Ming Yi Wang ◽  
Nan Qiao Zhou ◽  
Jun Hu
Keyword(s):  
Mechanical Properties ◽  
Cell Structure ◽  
Dioctyl Phthalate ◽  
Bubble Coalescence ◽  
Low Density ◽  
Foaming Agent ◽  
Elongation At Break ◽  
Foaming Process ◽  
Continuous Extrusion ◽  
Scanning Electron

Using supercritical CO2 as the foaming agent, rigid polyvinyl chloride (R-PVC) foam sheets were prepared in a continuous extrusion foaming system. The effects of dioctyl phthalate (DOP) on the rheological properties of PVC were investigated using a Brabender torque rheometer while other basic formula remained unchanged. The influences of DOP content on microstructure, mechanical properties and density of PVC micro foamed sheet were investigated with scanning electron microscopy (SEM). The results showed that the addition of DOP resulted in increased flexibility and the elongation at break of the foamed PVC sheet, while the mechanical properties of foamed PVC sheet decreased with the increase of DOP content, implying that excessive addition of DOP will cause gas escape and bubble coalescence in the foaming process. Low density PVC foam sheets with fine cell morphology were obtained when 2 phr DOP was added in PVCformula.

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