Effects of Chain Extension and Branching on the Properties of Poly (Ethylene-Terephthalate)-Organoclay Nanocomposites

2004 ◽  
Vol 856 ◽  
Author(s):  
Ali Emrah Keyfoglu ◽  
Ulku Yilmazer
Keyword(s):  
Ethylene Terephthalate ◽  
Interlayer Spacing ◽  
Chain Scission ◽  
Chain Extension ◽  
Twin Screw Extrusion ◽  
Poly Ethylene Terephthalate ◽  
Screw Extrusion ◽  
Organically Modified ◽  
Twin Screw ◽  
Poly Ethylene

ABSTRACTThe effects of chain extension and branching on the properties of nanocomposites produced from recycled poly (ethylene-terephthalate) and organically modified clay were investigated. As the potential chain extension/branching agent, maleic anhydride (MA) and pyromellitic dianhydride (PMDA) were used. The nanocomposites were prepared by twin-screw extrusion, followed by injection molding. Recycled poly (ethylene-terephthalate) was mixed with 2, 3 or 4 weight % of organically modified montmorillonite. During the second extrusion step, 0.5, 0.75 or 1 weight % of MA or PMDA was added to the products of the first extrusion. The effects of the sequence of addition of the ingredients on the final properties of the nanocomposites were also investigated. X-Ray Diffraction analysis showed that, the interlayer spacing of Cloisite 25A expanded from 19.21 Å to about 28–34 Å after processing with polymer indicating an intercalated structure. PMDA content, MA content and screw speed did not have a significant effect on the expanded interlayer distance. In the first extrusion step, nanocomposites containing 3% organoclay content gave significant increase in Young's modulus and decrease in elongation at break values indicating good interfacial adhesion. After the addition of anhydrides, it was observed that, in general PMDA improved the mechanical properties of the nanocomposite owing to the branching and chain extension effects that increase the molecular weight. However, MA did not significantly improve the properties, since in this case the chain scission seemed to be more dominant.

Morphology optimization of poly(ethylene terephthalate)/polyamide blends compatibilized via extension-dominated twin-screw extrusion

2021 ◽  
Vol 41 (3) ◽  
pp. 218-225
Author(s):  
Hao Chen ◽  
Molin Guo ◽  
David Schiraldi ◽  
João M. Maia
Keyword(s):  
Droplet Size ◽  
Ethylene Terephthalate ◽  
Aromatic Polyamide ◽  
Twin Screw Extrusion ◽  
Immiscible Polymers ◽  
Poly Ethylene Terephthalate ◽  
Screw Extrusion ◽  
Twin Screw ◽  
Order Of Magnitude ◽  
Poly Ethylene

Abstract Poly(ethylene terephthalate) (PET) and polyamide (PA) are immiscible polymers, which requires the use of compatibilizers to stabilize the morphology and achieve acceptable property levels. Therefore, controlling the degree of dispersion, especially the size of the disperse PA droplets in the PET matrix is of paramount importance. This study aims to improve the mixing, i.e., minimize PA droplet size, in immiscible and compatibilized PET/PA and PET/Nylon-MXD6 (MXD6) blends by resorting to extension-dominated mixing in twin-screw extrusion (TSE). MXD6 is an aromatic polyamide similar in polarity to PET, so it is expected that it will blend more effectively than is the case with aliphatic nylon-6 and PET. Two screw configurations are used, a benchmark shear-dominated screw with kneading blocks (KBs) in an aggressive configuration, and an extension-dominated screw configuration with static mixers with hyperbolic C–D channels, recently developed by our group, in place of the KBs. The results show that the use of extensional mixing elements (EMEs) in place of KBs results in a significant decrease of both average and maximum droplet size for all blends, and up to more than one order of magnitude between the most extreme cases of the KB-processed immiscible blend and EME-processed compatibilized blends.

Fabrication of improved overall properties of poly (ethylene terephthalate) by simultaneous chain extension and crystallization promotion

2018 ◽  
Vol 133 (3) ◽  
pp. 1447-1454 ◽  
Author(s):  
Yiyang Liu ◽  
Alvianto Wirasaputra ◽  
Zhijie Jiang ◽  
Shumei Liu ◽  
Jianqing Zhao ◽  
...  
Keyword(s):  
Ethylene Terephthalate ◽  
Chain Extension ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene

Effects of Halloysite Nanotubes on Mechanical and Thermal Stability of Poly(Ethylene Terephthalate)/Polycarbonate Nanocomposites

2015 ◽  
Vol 735 ◽  
pp. 8-12
Author(s):  
Nurul Ain Jamaludin ◽  
Azman Hassan ◽  
Norhayani Othman ◽  
Mohammad Jawaid
Keyword(s):  
Thermal Stability ◽  
Ethylene Terephthalate ◽  
Flexural Modulus ◽  
Halloysite Nanotubes ◽  
Mechanical And Thermal Properties ◽  
Poly Ethylene Terephthalate ◽  
Twin Screw ◽  
Poly Ethylene ◽  
The Impact ◽  
Thermal Stability Of

The objective of this study is to investigate the effect of halloysite nanotubes (HNTs) loading on mechanical and thermal properties of poly(ethylene terephthalate)/polycarbonate (PET/PC) nanocomposites. Nanocomposites containing 70PET/30PC and 2-8 phr HNTs were prepared by twin screw extruder followed by injection moulding. As the percentage of HNTs increased, the flexural modulus increased. However, the flexural strength decreased with increasing HNTs content. The impact strength also decreased when HNTs increased. Thermogravimetry analysis of PET/PC/HNTs nanocomposites showed higher thermal stability at high HNTs content. However, on further addition of HNTs up to 8 phr, thermal stability of the nanocomposites decreased due to the poor dispersion of HNTs.

Degradation process of low molar mass poly(ethylene terephthalate)/organically modified montmorillonite nanocomposites

2016 ◽  
Vol 30 (4) ◽  
pp. 504-520 ◽  
Author(s):  
Juliana A de Lima ◽  
Lays B Fitaroni ◽  
Daniel VA Chiaretti ◽  
Manuela LQA Kaneko ◽  
Sandra A Cruz
Keyword(s):  
Ethylene Terephthalate ◽  
Molar Mass ◽  
Degradation Process ◽  
Melt Processing ◽  
Platelet Surface ◽  
Modified Montmorillonite ◽  
Organically Modified Montmorillonite ◽  
Poly Ethylene Terephthalate ◽  
Organically Modified ◽  
Poly Ethylene

The aim of this work is to investigate the degradation of low molar mass poly(ethylene terephthalate) (PET)/organically modified montmorillonite (OMMT) clay nanocomposites prepared by melt processing. The rheological behavior in combination with transmission electron microscopic images suggests an intercalation and therefore a percolating network. Furthermore, the results indicate that the increase of organoclay content caused a degradation of PET during processing of PET/OMMT nanocomposites, once it was observed the PET molar mass decreases. The effect mentioned could be attributed to an increase of Brønsted acidic sites on the platelet surface, which is produced by the Hofmann elimination reaction of ammonium, and also the presence of residual metal compounds on clay surface might possibly favored the polymer matrix degradation process.

Preparation and Characterization of High-Density Polyethylene Blends and Recycled Poly(ethylene terephthalate)

2014 ◽  
Vol 695 ◽  
pp. 131-134 ◽  
Author(s):  
Mohd Nazry Salleh ◽  
Ruey Shan Chen ◽  
Mohd Hafizuddin Ab Ghani ◽  
Farizul Hafiz Kasim ◽  
Ahmad Sahrim
Keyword(s):  
High Density Polyethylene ◽  
Ethylene Terephthalate ◽  
Chemical Interaction ◽  
High Density ◽  
Impact Properties ◽  
Poly Ethylene Terephthalate ◽  
Twin Screw ◽  
Poly Ethylene ◽  
Methacrylate Copolymer ◽  
The Impact

Polymer blends based on recycled high density polyethylene (rHDPE) and recycled poly (ethylene terephthalate) (rPET) with two types of ethylene-glycidyl methacrylate copolymer (E-GMA), Lotader AX8840 and Lotader AX8900 as compatibilizer were produced in a co-rotating twin screw extruder. The effects of adding rPET content on the impact properties of rHDPE-rich blends were also investigated. The result showed an enhancement of about 80-270% in impact properties as compared to those of the Lotader AX8900. The impact strength also showed a decreasing trend as the rPET content was increased. The addition of E-GMA to the rHDPE/rPET blends was found to recover the blend toughness as well as improving the compatibility between HDPE and PET. In this study, the highest result was obtained for the rHDPE/rPET blends using Lotader AX8840 composition with 7.5% E-GMA content. FTIR analysis of the compatibilized blends confirmed the chemical interaction and improved interfacial bonding between the two phases.

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