Deformation-Induced Crystallization Behavior of Isotactic Polypropylene Sheets Containing a β-Nucleating Agent under Solid-State Stretching

The deformation-induced crystallization of an isotactic polypropylene (iPP) sheet containing a β-nucleating agent was evaluated. The phase transformation of the β-modifications was investigated and the crystal morphology was observed at room temperature after stretching at different temperatures. The results showed that the crystallinity increased after solid-state stretching. When the stretching temperature was below the initial crystallization temperature, stretching deformation promoted the orientation of amorphous molecular chains. When the deformation temperature exceeded the crystallization temperature, part of the β-modifications underwent a phase transformation process and was stretched into a shish-kebab structure. However, once the stretching temperature was close to the melting point, the β-modifications melted and recrystallized, and the shish-kebab structure underwent stress relaxation due to poor thermal stability, transforming into α-modifications. It was revealed that the crystal phase transformation mechanism of the β-modifications was based on the orientation of the molecular chains between the adjacent lamellae. In addition, the shish-kebab cylindrite structure played an important role in modifying the tensile and impact properties of the iPP sheet. The tensile and impact strengths increased by as much as 34% and 126%, respectively.

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Solid State Phase Transformation Mechanism in High Carbon Steel Under Compressive Load and with Varying Cr Percent

TMS 2018 147th Annual Meeting & Exhibition Supplemental Proceedings - The Minerals, Metals & Materials Series ◽

10.1007/978-3-319-72526-0_75 ◽

2018 ◽

pp. 797-802 ◽

Cited By ~ 1

Author(s):

Rumana Hossain ◽

Farshid Pahlevani ◽

Veena Sahajwalla

Keyword(s):

Phase Transformation ◽

Solid State ◽

Carbon Steel ◽

High Carbon Steel ◽

Compressive Load ◽

High Carbon ◽

Transformation Mechanism ◽

Solid State Phase Transformation

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Solid state and phase transformation mechanism of kaolin sintered with limestone for alumina extraction

Applied Clay Science ◽

10.1016/j.clay.2020.105771 ◽

2020 ◽

Vol 196 ◽

pp. 105771 ◽

Cited By ~ 1

Author(s):

A.B. ElDeeb ◽

V.N. Brichkin ◽

Martin Bertau ◽

Yu A. Savinova ◽

R.V. Kurtenkov

Keyword(s):

Phase Transformation ◽

Solid State ◽

Transformation Mechanism

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Change of Microwave Dielectric Loss during the Solid-Reaction Synthesis of SrFeCo0.5Oy

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.368-372.183 ◽

2008 ◽

Vol 368-372 ◽

pp. 183-184

Author(s):

Zhi Jun Xu ◽

Rui Qing Chu ◽

S.C. Cui ◽

Long Zhi Zhao ◽

Jin Son Zhang

Keyword(s):

Phase Transformation ◽

Solid State ◽

Dielectric Loss ◽

Solid State Reaction ◽

Perovskite Phase ◽

Reaction Synthesis ◽

Solid Reaction ◽

Microwave Dielectric ◽

Pure Perovskite Phase ◽

Different Temperatures

Rectangular cavity perturbation method was used to measure microwave dielectric loss (MDL) during the solid state reaction synthesis of SrFeCo0.5Oy. In the process of solid state reaction, the dielectric loss is investigated under different temperatures. The phases of the samples synthesized at different temperatures were characterized by XRD. The variation of MDL with temperature illustrates that the phase transformation occurs. The reasons why the pure perovskite phase can be obtained by using microwave processing were also discussed.

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Molecular Dynamics Study on Uniaxial Compression Transformation of Magnesium Alloy

NANO ◽

10.1142/s1793292021501186 ◽

2021 ◽

pp. 2150118

Author(s):

Qianhua Yang ◽

Chun Xue ◽

Zhibing Chu ◽

Yugui Li ◽

Lifeng Ma

Keyword(s):

Mechanical Properties ◽

Molecular Dynamics ◽

Phase Transformation ◽

Magnesium Alloy ◽

Strain Rate ◽

Uniaxial Compression ◽

Dynamics Simulation ◽

Basic Knowledge ◽

Transformation Mechanism ◽

Different Temperatures

As a new method of calculating materials, molecular dynamics simulation can effectively reproduce the mechanical behavior of materials at the atomic level. In this paper, through the construction of the AZ31 magnesium alloy model, the uniaxial compression deformation of magnesium alloy at different temperatures and strain rate is simulated by molecular dynamics method, the mechanical properties and microstructure changes of magnesium alloy are analyzed, the phase transformation mechanism of magnesium alloy under uniaxial compression is revealed, and the effects of temperature and strain rate on the phase transformation of magnesium alloy are explored at the nanometer scale. It provides a theoretical basis and necessary basic knowledge for the design and development of Mg-based nanostructured alloys with excellent mechanical properties.

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Preparation, Characterization of Substituted Aromatic Heterocyclic Phosphate Salts and the Application in Isotactic Polypropylene

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.652-654.463 ◽

2013 ◽

Vol 652-654 ◽

pp. 463-469

Author(s):

Li Juan Long ◽

Wen Tao He ◽

Min Min Zhang ◽

Kai Zhang ◽

Min He ◽

...

Keyword(s):

Optical Properties ◽

Isotactic Polypropylene ◽

Crystallization Temperature ◽

Nucleating Agent ◽

Nucleating Agents ◽

Absorption Bands ◽

Nucleation Effect ◽

Stretching Vibration ◽

Phosphate Salts ◽

Aromatic Heterocyclic

Substituted aromatic heterocyclic phosphate salts were synthesized by a new method and characterized by fourier transform infrared spectroscopy(FT-IR) and thermogravimetry (TG) method. The characteristic absorption bands ascribed to the stretching vibration of P=O group and P-O group verify the successful synthesis of substituted aromatic heterocyclic phosphate salts. When compared with sodium salt, the thermal stability of other salts declines. Their nucleation effects on isotactic polypropylene(iPP) were investigated with differential scanning calorimeter(DSC) and influences on mechanical, optical properties of iPP were also studied. The DSC result shows that with 0.15wt% nucleating agents incorporated into iPP, monovalent salts have a good performance, bivalent salts have less nucleation effect on the crystallization temperature. But the mass fraction of crystallinity of iPP with manganese salt could be increased by 5.2% even it has a weak ability relatively on crystallization temperature. And the mechanical and optical properties of iPP with manganese salt almost reach to iPP containing lithium salt. The results demonstrate that bivalent manganses salt is a kind of new effective nucleating agent when designing compound nucleating agents.

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Influence of a particulate nucleating agent on the quiescent and flow-induced crystallization of isotactic polypropylene

Polymer ◽

10.1016/j.polymer.2013.08.004 ◽

2013 ◽

Vol 54 (21) ◽

pp. 5883-5891 ◽

Cited By ~ 28

Author(s):

Nilesh Patil ◽

Carmine Invigorito ◽

Markus Gahleitner ◽

Sanjay Rastogi

Keyword(s):

Isotactic Polypropylene ◽

Nucleating Agent ◽

Induced Crystallization ◽

Flow Induced Crystallization

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Solvent-induced crystallization of isotactic polypropylene in cyclohexane at different temperatures

Polymer ◽

10.1016/0032-3861(91)90510-p ◽

1991 ◽

Vol 32 (5) ◽

pp. 856-859 ◽

Cited By ~ 6

Author(s):

V. Vittoria

Keyword(s):

Isotactic Polypropylene ◽

Different Temperatures ◽

Induced Crystallization

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Accelerating shear-induced crystallization and enhancing crystal orientation of isotactic-polypropylene via nucleating agent self-assembly

Polymer ◽

10.1016/j.polymer.2018.10.066 ◽

2018 ◽

Vol 158 ◽

pp. 213-222 ◽

Cited By ~ 5

Author(s):

Baobao Chang ◽

Konrad Schneider ◽

Bo Lu ◽

Roland Vogel ◽

Guoqiang Zheng ◽

...

Keyword(s):

Isotactic Polypropylene ◽

Self Assembly ◽

Crystal Orientation ◽

Nucleating Agent ◽

Induced Crystallization

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Effect of Different Nucleating Agents on the Crystallization of Ziegler-Natta Isotactic Polypropylene

International Journal of Polymer Science ◽

10.1155/2016/9839201 ◽

2016 ◽

Vol 2016 ◽

pp. 1-9 ◽

Cited By ~ 6

Author(s):

Felipe Avalos-Belmontes ◽

Luis Francisco Ramos-deValle ◽

Adriana Berenice Espinoza-Martínez ◽

Juan Guillermo Martínez-Colunga ◽

Eduardo Ramírez-Vargas ◽

...

Keyword(s):

Carbon Nanotubes ◽

Carbon Nanofibers ◽

Isotactic Polypropylene ◽

Crystallization Temperature ◽

Carbon Nanoparticles ◽

Crystallization Process ◽

Life Time ◽

Nucleating Agent ◽

Crystalline Form ◽

Nucleating Agents

Ziegler-Natta isotactic polypropylene (iPP) was melt mixed with four different nucleating agents (carbon nanotubes (CNT), carbon nanofibers (CNF), lithium benzoate (LiBe), and a sorbitol derivative (Millad)) in order to study their effect on the crystallization of iPP. It was found that the four different nucleating agents promote the alpha crystalline form. At 0.01 wt%, the carbon nanoparticles produced the higher crystallization temperature “Tc” (~119°C), whereas, at 0.10 wt%, LiBe and Millad produced a markedly higherTc(~125°C).Tcof pure iPP was 111°C. With 0.1 wt% nucleating agent, at 120°C, the crystallization half-life time of PP, when using LiBe or Millad, was 15 times faster than for pure PP, whereas, when using carbon nanoparticles, it was 20–25 times faster. At 135°C, with 0.01 wt% nucleating agent, the isothermal crystallization process of iPP was completed after 25 min, as well as with Millad. With LiBe, it was completed after just 15 min and, with any of the carbon nanoparticles, it was practically over after only a couple of minutes.

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