Approach to Fabricating Thermoplastic Polyurethane Blends and Foams with Tunable Properties by Twin-Screw Extrusion and Microcellular Injection Molding

2013 ◽  
Vol 33 (1) ◽  
Author(s):  
Hao-Yang Mi ◽  
Xin Jing ◽  
Max R. Salick ◽  
Wendy C. Crone ◽  
Xiang-Fang Peng ◽  
...  
Keyword(s):  
Injection Molding ◽  
Thermoplastic Polyurethane ◽  
Twin Screw Extrusion ◽  
Tunable Properties ◽  
Screw Extrusion ◽  
Microcellular Injection Molding ◽  
Twin Screw

Preparation and Characterization of Polypropylene/MMT Nanocomposites

2014 ◽  
Vol 893 ◽  
pp. 132-135 ◽  
Author(s):  
Branislav Duleba ◽  
František Greškovič ◽  
Emil Spišák ◽  
Ľudmila Dulebová
Keyword(s):  
Injection Molding ◽  
Polymer Nanocomposites ◽  
Main Part ◽  
Paper Study ◽  
Twin Screw Extrusion ◽  
Screw Extrusion ◽  
Twin Screw ◽  
Polypropylene Matrix ◽  
Shape Changes

In this paper, study of preparation and testing of polymer nanocomposites (PNC) based on polypropylene matrix and montmorillonite nanofillers is described. Samples were prepared by twin-screw extrusion and injection molding to final shape. Changes of basic properties of these PNC ́s were tested and described in main part of this article.

Characterization of a Porous Multifunctional Nanocomposite for Pressure Sensing

2012 ◽  
Author(s):  
Reza Rizvi ◽  
Hani Naguib ◽  
Elaine Biddiss
Keyword(s):  
Thermoplastic Polyurethane ◽  
Pressure Sensors ◽  
Multiwall Carbon Nanotubes ◽  
Twin Screw Extrusion ◽  
Pressure Sensing ◽  
Elastomeric Matrix ◽  
Screw Extrusion ◽  
Twin Screw ◽  
Pressure Resistance

This study focuses on the characterization of a porous multifunctional elastomer-CNT nanocomposites for potential use as pressure sensors. A thermoplastic polyurethane (TPU) was chosen as an elastomeric matrix, which was reinforced with multiwall carbon nanotubes (0–10 wt%) by high shear twin screw extrusion mixing. Porosity was introduced to the composites through the phase separation of a single TPU-CO2 solution. Interactions between MWNT and TPU were elucidated through calorimetry, gravimetric decomposition, conductivity measurements and microstructure imaging. The piezoresistance (pressure-resistance) behavior of the nanocomposites was investigated and found to be dependent on MWNT concentration and nanocomposite microstructure.

Melt Processing of Bioplastic Composites via Twin Screw Extrusion and Injection Molding

2014 ◽  
Vol 53 (4) ◽  
pp. 379-386 ◽  
Author(s):  
Michael A. Gunning ◽  
Luke M. Geever ◽  
John A. Killion ◽  
John G. Lyons ◽  
Clement L. Higginbotham
Keyword(s):  
Injection Molding ◽  
Melt Processing ◽  
Twin Screw Extrusion ◽  
Screw Extrusion ◽  
Twin Screw

Mechanical Properties of Polypropylene Based Composites Reinforced with B4C

2013 ◽  
Vol 685 ◽  
pp. 19-23 ◽  
Author(s):  
Ali Sinan Dike ◽  
Harun Mindivan
Keyword(s):  
Mechanical Properties ◽  
Maleic Anhydride ◽  
Yield Strength ◽  
Injection Molding ◽  
Scratch Resistance ◽  
Twin Screw Extrusion ◽  
Elongation At Break ◽  
Screw Extrusion ◽  
Twin Screw

The present work aims to compare the mechanical properties of Polypropylene (PP) based composites reinforced with B4C. Maleic Anhydride Modified Polypropylene (MAPP) was added to improve the B4C-matrix interphase. Processing has been carried out by twin-screw extrusion and injection molding. By adding the B4C particles to the PP and PP+MAPP matrix, the yield strength, shore D hardness, microhardness and relative scratch resistance increased gradually, but PP+MAPP/B4C composites showed better overall mechanical properties than the PP/B4C composites. However, elongation at break values occurred for all composites dropped with the B4C content, and PP+MAPP/B4C composites exhibited lower elongations at break than PP/B4C composites.

scholarly journals In-Line Rheo-Optical Investigation of the Dispersion of Organoclay in a Polymer Matrix during Twin-Screw Compounding

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2128
Author(s):  
Paulo F. Teixeira ◽  
José A. Covas ◽  
Loïc Hilliou
Keyword(s):  
Local Heating ◽  
Polymer Nanocomposite ◽  
Structural Rearrangement ◽  
Particle Dispersion ◽  
Optical Investigation ◽  
Twin Screw Extrusion ◽  
Clay Particles ◽  
Clay Dispersion ◽  
Screw Extrusion ◽  
Twin Screw

The dispersion mechanisms in a clay-based polymer nanocomposite (CPNC) during twin-screw extrusion are studied by in-situ rheo-optical techniques, which relate the CPNC morphology with its viscosity. This methodology avoids the problems associated with post extrusion structural rearrangement. The polydimethylsiloxane (PDMS) matrix, which can be processed at ambient and low temperatures, is used to bypass any issues associated with thermal degradation. Local heating in the first part of the extruder allows testing of the usefulness of low matrix viscosity to enhance polymer intercalation before applying larger stresses for clay dispersion. The comparison of clay particle sizes measured in line with models for the kinetics of particle dispersion indicates that larger screw speeds promote the break-up of clay particles, whereas smaller screw speeds favor the erosion of the clay tactoids. Thus, different levels of clay dispersion are generated, which do not simply relate to a progressively better PDMS intercalation and higher clay exfoliation as screw speed is increased. Reducing the PDMS viscosity in the first mixing zone of the screw facilitates dispersion at lower screw speeds, but a complex interplay between stresses and residence times at larger screw speeds is observed. More importantly, the results underline that the use of larger stresses is inefficient per se in dispersing clay if sufficient time is not given for PDMS to intercalate the clay galleries and thus facilitate tactoid disruption or erosion.

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