Condensed Mode Cooling for Ethylene Polymerization: Part III. The Impact of Induced Condensing Agents on Particle Morphology and Polymer Properties

2016 ◽  
Vol 217 (13) ◽  
pp. 1521-1528 ◽  
Author(s):  
Montree Namkajorn ◽  
Arash Alizadeh ◽  
Dario Romano ◽  
Sanjay Rastogi ◽  
Timothy F. L. McKenna
Keyword(s):  
Ethylene Polymerization ◽  
Particle Morphology ◽  
Polymer Properties ◽  
The Impact ◽  
Condensing Agents

Active O,Npy,N-Titanium(IV) Fluoride Precatalysts for Ethylene Polymerization: Exploring “Fluoride Effects” on Polymer Properties and Catalytic Performance

2016 ◽  
Vol 35 (9) ◽  
pp. 1183-1191 ◽  
Author(s):  
Luka A. Wright ◽  
Eric G. Hope ◽  
Gregory A. Solan ◽  
Warren B. Cross ◽  
Kuldip Singh
Keyword(s):  
Ethylene Polymerization ◽  
Catalytic Performance ◽  
Polymer Properties

The impact of spray drying outlet temperature on the particle morphology of mannitol

2011 ◽  
Vol 213 (1-3) ◽  
pp. 27-35 ◽  
Author(s):  
Stephan G. Maas ◽  
Gerhard Schaldach ◽  
Eva M. Littringer ◽  
Axel Mescher ◽  
Ulrich J. Griesser ◽  
...  
Keyword(s):  
Spray Drying ◽  
Particle Morphology ◽  
Outlet Temperature ◽  
The Impact

scholarly journals Probing the Influence of Multiscale Heterogeneity on Effective Properties of Graphite Electrodes

2021 ◽  
Author(s):  
Chance A. Norris ◽  
Mukul Parmananda ◽  
Scott Alan Roberts ◽  
Partha P. Mukherjee
Keyword(s):  
Spatial Heterogeneity ◽  
Transport Properties ◽  
Effective Properties ◽  
Lithium Ion ◽  
Particle Morphology ◽  
Electrochemical Characteristics ◽  
Pore Scale ◽  
Structural Anisotropy ◽  
Graphite Electrodes ◽  
The Impact

Graphite electrodes in the lithium-ion battery exhibit various particle shapes, including spherical and platelet morphologies, which influence structural and electrochemical characteristics. It is well established that porous structures exhibit spatial heterogeneity, and particle morphology can influence transport properties. The impact of particle morphology on the heterogeneity and anisotropy of geometric and transport properties has not been previously studied. This study characterizes the spatial heterogeneities of eighteen graphite electrodes at multiple length scales by calculating and comparing structural anisotropy, geometric quantities, and transport properties (pore-scale tortuosity and electrical conductivity). We found that particle morphology and structural anisotropy play an integral role in determining the spatial heterogeneity of directional tortuosity and its dependency on pore-scale heterogeneity. Our analysis reveals that the magnitude of in-plane and through-plane tortuosity difference influences the multiscale heterogeneity in graphite electrodes.

scholarly journals Optimization and Modeling of an Emulsion Polymerization Reactor

2021 ◽  
Author(s):  
Narges Ghadi
Keyword(s):  
Emulsion Polymerization ◽  
Water Solubility ◽  
Monomer Conversion ◽  
High Water ◽  
Oscillatory Behavior ◽  
Operating Conditions ◽  
Polymer Properties ◽  
Continuous Polymerization ◽  
Simulation Results ◽  
The Impact

A mathematical model was developed to simulate emulsion polymerization in batch, semi-batch and continuous reactors for monomers with high water solubility and significant desorption such as vinyl acetate. The effects of operating conditions such as initiator and emulsifier concentration as well as reactor temperature have been studied. The simulation results revealed the sensitivity of polymer properties and monomer conversion to variation of these operating conditions. Furthermore, the impact of monomer soluble impurities on reduction of monomer conversion has been investigated. In order to control polymer molecular weight, application of chain transfer agents such as t-nonyl mercaptan was suggested. Generally, the simulation results fitted well [with] experimental data from the literature. Several optimizing policies were considered to enhance the reaction operation for better product quality. During continuous polymerization, the reactor demonstrates oscillatory behavior throughout the operation. A new reactor train configuration was consistent with the aim of damping the oscillations and producing high-quality latex.

Remote dibenzocycloheptyl substitution on a bis(arylimino)pyridyl-iron ethylene polymerization catalyst; enhanced thermal stability and unexpected effects on polymer properties

2021 ◽  
Author(s):  
Liwei Guo ◽  
Wenjuan Zhang ◽  
Furong Cao ◽  
Youshu Jiang ◽  
Randi Zhang ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Ethylene Polymerization ◽  
Chloride Complexes ◽  
Polymerization Catalyst ◽  
Polymer Properties

Four examples of para-dibenzocycloheptyl-substituted 2,6-bis(arylimino)pyridyl-iron(II) chloride complexes, [2,6-{(2-R1,4-(C15H13),6-R2C6H2)N=CMe}2C5H3N]FeCl2 (R1 = R2 = Me Fe1, Et Fe2, iPr Fe3, R1 = Me, R2 = Et Fe4), have been synthesized and characterized...

scholarly journals Three-Dimensional Printed PLA and PLA/PHA Dumbbell-Shaped Specimens: Material Defects and Their Impact on Degradation Behavior

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 2005 ◽  
Author(s):  
Joanna Rydz ◽  
Jakub Włodarczyk ◽  
Jennifer Gonzalez Ausejo ◽  
Marta Musioł ◽  
Wanda Sikorska ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Hydrolytic Degradation ◽  
Processing Parameters ◽  
Polymer Materials ◽  
Original Research ◽  
Polymer Properties ◽  
Subsequent Behavior ◽  
And Behavior ◽  
The Impact ◽  
Printing Direction

The use of (bio)degradable polymers, especially in medical applications, requires a proper understanding of their properties and behavior in various environments. Structural elements made of such polymers may be exposed to changing environmental conditions, which may cause defects. That is why it is so important to determine the effect of processing conditions on polymer properties and also their subsequent behavior during degradation. This paper presents original research on a specimen’s damage during 70 days of hydrolytic degradation. During a standard hydrolytic degradation study of polylactide and polylactide/polyhydroxyalkanoate dumbbell-shaped specimens obtained by 3D printing with two different processing build directions, exhibited unexpected shrinkage phenomena in the last degradation series, representing approximately 50% of the length of the specimens irrespective of the printing direction. Therefore, the continuation of previous ex-ante research of advanced polymer materials is presented to identify any possible defects before they arise and to minimize the potential failures of novel polymer products during their use and also during degradation. Studies on the impact of a specific processing method, i.e., processing parameters and conditions, on the properties expressed in molar mass and thermal properties changes of specimens obtained by three-dimensional printing from polyester-based filaments, and in particular on the occurrence of unexpected shrinkage phenomena after post-processing heat treatment, are presented.

scholarly journals Efficient Preparation and Performance Characterization of the HMX/F2602 Microspheres by One-Step Granulation Process

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Conghua Hou ◽  
Xinlei Jia ◽  
Jingyu Wang ◽  
Yingxin Tan ◽  
Yuanping Zhang ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Thermal Stability ◽  
Particle Size ◽  
Particle Morphology ◽  
Xrd Analysis ◽  
Impact Sensitivity ◽  
Scanning Calorimetry ◽  
Granulation Process ◽  
One Step ◽  
The Impact

A new one-step granulation process for preparing high melting explosive- (HMX-) based PBX was developed. HMX/F2602 microspheres were successfully prepared by using HMX and F2602 as the main explosive and binder, respectively. The particle morphology, particle size, crystal structure, thermal stability, and impact sensitivity of the as-prepared HMX/F2602 microspheres were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), laser particle size analyzer, differential scanning calorimetry (DSC), and impact sensitivity test, respectively. The SEM analysis indicated successful coating of F2602 on the surface of HMX, and the resulting particles are ellipsoidal or spherical with a median particle size of 940 nm; the XRD analysis did not show any change in the crystal structure after the coating and still has β-HNX crystal structure; according to the DSC analysis, HMX/F2602 prepared by the new method has better thermal stability compared to that prepared by the water suspension process. The impact sensitivity of HMX/F2602 prepared by this one-step granulation process decreased, and its characteristic height H50 increased from 37.62 to 40.13 cm, thus significantly improving the safety performance. More importantly, this method does not need the freeze-drying process after recrystallization, thus increasing the efficiency by 2 to 3 times.

Effects of ethylene polymerization conditions on the activity of SiO2-supported zirconocene and on polymer properties

1999 ◽  
Vol 37 (13) ◽  
pp. 1987-1996 ◽  
Author(s):  
Jo�o Henrique Zimnoch Dos Santos ◽  
Marcelo Barbosa Da Rosa ◽  
Cristiano Krug ◽  
Fernanda Chiarello Stedile ◽  
Monica Carcuchinski Haag ◽  
...  
Keyword(s):  
Ethylene Polymerization ◽  
Polymer Properties ◽  
Polymerization Conditions
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