High-pressure induced formation of isotactic polypropylene mesophase: Synergistic effect of pressure and pressurization rate

2018 ◽  
Vol 59 (3) ◽  
pp. 439-446 ◽  
Author(s):  
Jingjing Huang ◽  
Xiaobo Fu ◽  
Chunguang Shao ◽  
Zhe Ma ◽  
Yaming Wang ◽  
...  
Keyword(s):  
High Pressure ◽  
Synergistic Effect ◽  
Isotactic Polypropylene ◽  
Effect Of Pressure ◽  
Pressurization Rate

Properties of nanocomposites based on isotactic polypropylene and high-pressure polyethylene with metal-containing nanofillers

2020 ◽  
pp. 59-64
Author(s):  
N. I. Kurbanova ◽  
◽  
T. M. Gulieva ◽  
N. Ya. Ischenko ◽  
◽  
...  
Keyword(s):  
High Pressure ◽  
Synergistic Effect ◽  
Polymer Matrix ◽  
Isotactic Polypropylene ◽  
Rheological Parameters ◽  
Mechanochemical Method ◽  
X Ray ◽  
Effect Of Additives ◽  
High Pressure Polyethylene ◽  
Properties Of Composites

The effect of additives of nanofillers (NF) containing nanoparticles (NP) of copper oxide, stabilized by a polymer matrix of maleized polyethylene (MPE), obtained by the mechanochemical method, on the properties of composites based on isotactic polypropylene (PP) and high-pressure polyethylene (PE) was studied by X-ray phase (XRD) and thermogravimetric (TGA) analyzes. The enhancement of strength, deformation, and rheological parameters, as well as the thermo-oxidative stability of the obtained nanocomposites was revealed, which, apparently, is due to the synergistic effect of the interaction of copper-containing nanoparticles with anhydride groups of MPE. It is shown that nanocomposites based on PP/PE/NF can be processed both by pressing and injection molding and extrusion, which expands the scope of its application.

scholarly journals High-Pressure Crystallization of iPP Nucleated with 1,3:2,4-bis(3,4-dimethylbenzylidene)sorbitol

Polymers ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 145
Author(s):  
Przemyslaw Sowinski ◽  
Ewa Piorkowska ◽  
Severine A. E. Boyer ◽  
Jean-Marc Haudin
Keyword(s):  
Grain Size ◽  
High Pressure ◽  
Isotactic Polypropylene ◽  
Thermal Conditions ◽  
Elevated Pressure ◽  
Lower Pressure ◽  
Effect Of Pressure ◽  
Cooling Crystallization ◽  
Polycrystalline Aggregates ◽  
Pressure Crystallization

1,3:2,4-bis(3,4-dimethylbenzylidene)sorbitol (DMDBS) is highly effective in nucleation of the α- form of isotactic polypropylene (iPP). However, its role in high-pressure crystallization of iPP, facilitating the formation of the γ- polymorph, has not been explored. The present paper focuses on the influence of DMDBS on nucleation of high-pressure crystallization of iPP. iPP with 0.2–1.0 wt.% of the DMDBS was crystallized under elevated pressure, up to 300 MPa, in various thermal conditions, and then analyzed by PLM, WAXD, SEM, and DSC. During cooling, crystallization temperatures (Tc) were determined. It was found that under high-pressure DMDBS nucleated crystallization of iPP in the orthorhombic γ- form. As a consequence, Tc and the γ- form content increased for the nucleated iPP, while the size of polycrystalline aggregates decreased, although the effects depended on DMDBS content. The significant increase of Tc and the decrease of grain size under high pressure of 200–300 MPa required higher content of DMDBS than the nucleation of the α-form under lower pressure, possibly due to the effect of pressure on crystallization of DMDBS itself, which is a prerequisite for its nucleating activity.

The structure of KH2PO4and KD2PO4at high pressure (∼20 KBAR) in relation to the effect of pressure on Tc

1978 ◽  
Vol 21 (1) ◽  
pp. 439-440 ◽  
Author(s):  
R. J. Nelmes ◽  
N. S. J. Kennedy ◽  
E. Baharie ◽  
A. W. Hewat
Keyword(s):  
High Pressure ◽  
Effect Of Pressure
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