scholarly journals Reactive Extrusion of Maleic-Anhydride-Grafted Polypropylene by Torque Rheometer and Its Application as Compatibilizer

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 495
Author(s):  
Asra Tariq ◽  
Nasir M. Ahmad ◽  
Muhammad Asad Abbas ◽  
M Fayzan Shakir ◽  
Zubair Khaliq ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Maleic Anhydride ◽  
Benzoyl Peroxide ◽  
Melt Flow Index ◽  
Reactive Extrusion ◽  
Side Chain ◽  
Flow Index ◽  
Viscosity Change ◽  
Chain Reactions ◽  
Molecular Weight Product

This study is based upon the functionalization of polypropylene (PP) by radical polymerization to optimize its properties by influencing its molecular weight. Grafting of PP was done at different concentrations of maleic anhydride (MAH) and benzoyl peroxide (BPO). The effect on viscosity during and after the reaction was studied by torque rheometer and melt flow index. Results showed that a higher concentration of BPO led to excessive side-chain reactions. At a high percentage of grafting, lower molecular weight product was produced, which was analyzed by viscosity change during and after the reaction. Percentage crystallinity increased by grafting due to the shorter chains, which consequently led to an improvement in the chain’s packing. Prepared Maleic anhydride grafted polypropylene (MAH-g-PP) enhanced interactions in PP-PET blends caused a partially homogeneous blend with less voids.

Processability predictions for mechanically recycled blends of linear polymers

2020 ◽  
Vol 40 (9) ◽  
pp. 771-781
Author(s):  
Janne van Gisbergen ◽  
Jaap den Doelder
Keyword(s):  
Molecular Weight ◽  
Circular Economy ◽  
Melt Flow Index ◽  
Building Blocks ◽  
Experimental Designs ◽  
New Method ◽  
Flow Index ◽  
Linear Polymers ◽  
Combined Method

AbstractRecycling of thermoplastic polymers is an important element of sustainable circular economy practices. The quality of mechanically recycled polymers is a concern. A method is presented to predict the structure and processability of recycled blends of polymers based on processability knowledge of their virgin precursor components. Blending rules at molecular weight distribution level are well established and form the foundation of the new method. Two essential fundamental building blocks are combined with this foundation. First, component and blend structure are related to viscosity via tube theories. Second, viscosity is related to melt flow index via a continuum mechanics approach. Emulator equations are built based on virtual experimental designs for fast forward and reverse calculations directly relating structure to viscosity and processability. The new combined method is compared with empirical blend rules, and shows important similarities and also clear quantitative differences. Finally, the new method is applied to practical recycling quality challenges.

Melt Processed Polymer Blends for Potential Regenerative Medicine Applications

2014 ◽  
Vol 679 ◽  
pp. 92-100
Author(s):  
Elaine Kenny ◽  
Declan M. Devine ◽  
Clement L. Higginbotham ◽  
Luke M. Geever
Keyword(s):  
Molecular Weight ◽  
Differential Scanning Calorimetry ◽  
Regenerative Medicine ◽  
Polyethylene Oxide ◽  
Melt Flow Index ◽  
Flow Index ◽  
Biodegradable Implants ◽  
Scanning Calorimetry ◽  
Breakdown Rate

There is an urgent and unmet requirement for biocompatible and biodegradable implants that gradually resorb when implanted in vivo. This study examines the potential of melt extruded thermoplastics polyethylene oxide (PEO) and polycaprolactone (PCL) in the area of regenerative medicine. Various ratios of PEO and PCL were melt blended and analysed in order to obtain an optimised breakdown rate. Subsequently the effect of varying the molecular weight of PCL using a constant molecular weight PEO was also examined. Samples were characterised using melt flow index (MFI), differential scanning calorimetry (DSC) and breakdown analysis. It was found that by altering both the concentrations of PEO/PCL and the molecular weight of PCL, melt viscosity, breakdown rate and thermal properties could be modulated to produce potential implant materials with a tailored breakdown rate.

Predicting Molecular Weight Distribution, Melt Flow Index, and Bulk Density in a Polypropylene Reactor via a Validated Mathematical Model

2021 ◽  
Vol 55 (1) ◽  
pp. 153-166
Author(s):  
Gholam Hossain Varshouee ◽  
Amir Heydarinasab ◽  
Ali Vaziri ◽  
Behrooz Roozbahani
Keyword(s):  
Mathematical Model ◽  
Molecular Weight ◽  
Bulk Density ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Melt Flow Index ◽  
Flow Index ◽  
Melt Flow

Preparation of high molecular weight and elastic copolyester by reactive extrusion with diisocyanate compound for laser printing process

2012 ◽  
Vol 32 (3) ◽  
Author(s):  
Hyung-Jin Roh ◽  
Doe Kim ◽  
Dong-Ho Lee ◽  
Keun-Byoung Yoon
Keyword(s):  
Rheological Properties ◽  
Loss Modulus ◽  
Complex Viscosity ◽  
Melt Flow Index ◽  
Reactive Extrusion ◽  
Flow Index ◽  
Printing Process ◽  
Laser Printing ◽  
Printing Processes ◽  
Trimethylol Propane

Abstract A branched copolyester was synthesized using dimethyl terephthalate (DMT), 2,2-bis[4-(2-hydroxypropoxy)phenyl]propane, ethylene glycol (EG) and 2-(hydroxymethyl)-2- ethylpropane-1,3-diol (trimethylol propane, TMP). The branched copolyester and p-phenylene diisocyanate (PPDI) were melt extruded to enhance the melt viscosity and elasticity for use as a toner binder in the laser printing process. The effects of PPDI content on melt, thermal and rheological properties of the chain-extended copolyester were investigated. The melt flow index (MI) decreased with increasing amount of PPDI, due to a reaction between the hydroxyl chain end and isocyanate group. The storage modulus, loss modulus and complex viscosity of the chain extended copolyester were higher and the modified Cole-Cole plots revealed the chain extended copolyester to have higher elasticity than that of the branched copolyester. The chain extended copolyester exhibited suitable melt and rheological properties for applications as a toner binder in the laser printing processes.

scholarly journals Melt Rheology of Renewable Polymers and of New Materials Based on them as Tool in Controlling the 3D/4D Printability

2021 ◽  
Vol 57 (4) ◽  
pp. 77-87
Author(s):  
Doina Dimonie ◽  
Nicoleta Dragomir
Keyword(s):  
Molecular Weight ◽  
Melt Flow Index ◽  
Melt Processing ◽  
Operating Conditions ◽  
Flow Index ◽  
Flow Conditions ◽  
Index Method ◽  
Pre Treatment ◽  
Processing Techniques ◽  
Selection Of

The article presents results regarding the use of the melt flow index method (MFIM) in estimating the rheological properties of polylactic acid (PLA) and PLA-based materials, as tool in the selection of the operating conditions at their shaping into filaments and for 3D printing with thus obtained filaments. Based on the MFIM, the molecular weight of various PLA grade commonly used in melt processing techniques, including printing, were qualitatively compared. It was found that PLA for printing has the lowest molecular weight as compared with the PLA melt processed through injection, extrusion, thermoforming. It has been also shown that the MFIM can be used to verify the efficiency of drying, pre-treatment always needed to be done, before filaments obtaining and/or printing, especially in case of renewable polyesters. By simulating the printing at the indexer, via depositing successive layers, one over the other, it was possible to estimate the optimal flow conditions that ensure a good adhesion between the deposited layers. The estimation of the condition which ensure the needed adhesion between the deposited layers with the help of the MFIM was verified with good results on a grade of high loaded PLA achieved according to an original formulation.

scholarly journals Melt flow index of low-density polyethylene determination based on molecular weight and branching properties

2019 ◽  
Vol 1349 ◽  
pp. 012094
Author(s):  
A Azmi ◽  
S A Sata ◽  
F S Rohman ◽  
N Aziz
Keyword(s):  
Molecular Weight ◽  
Melt Flow Index ◽  
Low Density Polyethylene ◽  
Flow Index ◽  
Low Density ◽  
Melt Flow

Rotomolding and polyethylene composites with rotomolded lignocellulosic materials: A review

2020 ◽  
Vol 39 (11-12) ◽  
pp. 459-472
Author(s):  
Lumirca Del Valle Espinoza León ◽  
Viviane Alves Escocio ◽  
Leila Lea Yuan Visconte ◽  
Julio Cesar Jandorno Junior ◽  
Elen Beatriz Acordi Vasques Pacheco
Keyword(s):  
Maleic Anhydride ◽  
Polymer Matrix ◽  
Polymer Melt ◽  
Polymeric Materials ◽  
Melt Flow Index ◽  
Polymer Particle ◽  
Morphological Properties ◽  
Flow Index ◽  
Main Process ◽  
Wood Fibers

Rotomolding is a versatile process used in the manufacture of thermoplastic polymeric materials to produce large hollow plastic parts. The aim of this review article was to discuss the rotomolding process and show the properties of the polyethylene composite and rotomolded lignocellulosic fibers, which are processed for prolonged periods under temperature. The main process parameters studied are the shaft speed of the equipment, molding temperature, polymer particle size, polymer melt flow index, and amount of material, which must be well controlled to achieve a non-degraded product with homogeneous thickness and no porosity. Rotomolded composites containing sisal, pine, coir, banana, flax, and maple wood fibers, among others, have been evaluated primarily for their mechanical (impact, flexural, and tensile strength) and morphological properties. The type, content, and treatment of lignocellulosic fillers are the most widely studied variables in polyethylene-based rotomolded composites. Fiber content was the variable that most influenced mechanical properties, particularly impact strength and hardness due to the voids formed by the hydrodynamic volume between the polymer matrix and lignocellulosic filler. Chemical treatment of the fiber by mercerization with NaOH made it more hydrophobic and the addition of maleic anhydride-grafted polyethylene as a coupling agent improved the interfacial adhesion between the non-polar polymer matrix and polar filler. However, the best mechanical property results were obtained with the use of maleic anhydride-grafted polyethylene.

scholarly journals Thermal degradation of polypropylene reprocessed in a co-rotating twin-screw extruder: kinetic model and relationship between Melt Flow Index and Molecular weight

2021 ◽  
Vol 20 (2) ◽  
pp. 1079-1091
Author(s):  
L. Martínez-Jothar ◽  
◽  
I. Montes-Zavala ◽  
N. Rivera-García ◽  
Y. Díaz-Ceja ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Kinetic Model ◽  
Thermal Degradation ◽  
Melt Flow Index ◽  
Flow Index ◽  
Twin Screw Extruder ◽  
Melt Flow ◽  
Screw Extruder ◽  
Twin Screw

scholarly journals EFFECT OF POLYETHYLENE MOLECULAR MASS CHARACTERISTICS ON SLIP EFFECT

2016 ◽  
Vol 11 (5) ◽  
pp. 91-93
Author(s):  
A. A. Yurkin ◽  
I. D. Simonov-Emelyanov ◽  
P. V. Surikov ◽  
N. L. Shembel
Keyword(s):  
Molecular Weight ◽  
Molecular Mass ◽  
Rheological Properties ◽  
Melt Flow Index ◽  
Flow Index ◽  
Slip Effect ◽  
Melt Flow ◽  
Molecular Weight Characteristics ◽  
Different Temperatures ◽  
Different Molecular Weight

The rheological properties of polyethylene with different molecular weight characteristics were studied. Difference of molecular weight characteristics was found on the basis of melt flow index, and slip effect in the molten polyethylene flow was studied. The presence of slip effect is found in case of flowing polyethylene with a higher molecular weight in contrast to polyethylene with lower molecular weight at different temperatures. Changes of the slip effect parameters upon mixing polyethylenes with very much different molecular weight characteristics were studied.

Sign in / Sign up

Export Citation Format

Share Document