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

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.

Download Full-text

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

MRS Proceedings ◽

10.1557/proc-856-bb3.6 ◽

2004 ◽

Vol 856 ◽

Cited By ~ 1

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.

Download Full-text

Microwave Accelerated Methanolysis of Poly(ethylene terephthalate)

10.26434/chemrxiv-2021-8h75h ◽

2021 ◽

Author(s):

Bryn Monnery

Keyword(s):

Hot Spots ◽

Energy Use ◽

Ethylene Terephthalate ◽

Economic Value ◽

Active Surface ◽

Virgin Material ◽

Microwave Reactor ◽

Poly Ethylene Terephthalate ◽

Order Of Magnitude ◽

Poly Ethylene

Poly(ethylene terephthalate) (PET) is an important commodity polymer that has the potential to be 100% recycled, but this is currently not economically viable as the costs of recovering the starting materials are greater than virgin materials. As well as PET, there are a number of other interesting poly(terephthalate)s which have higher economic value. However, for many of these, virgin material is necessary to avoid contamination with ET units. This can be avoided by chemically deconstructing the PET to simple terephthalates. In this work, we show that dimethyl terephthalate (DMT) can be easily obtained from PET, in high purity (> 99.5% for the crude) with a relatively low energy use (ca. 0.3 Mj.g-1), by using a microwave reactor. In a microwave reactor the methanolysis proceeds an order of magnitude faster than in a conventional reactor. This is apparently due to cavitation caused by hot-spots, which break up the PET, increasing the active surface, and an increased population of PET particles above the Ea in the hot zones.

Download Full-text

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

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.735.8 ◽

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.

Download Full-text

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

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.695.131 ◽

2014 ◽

Vol 695 ◽

pp. 131-134 ◽

Cited By ~ 2

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.

Download Full-text

Effects of extrusion conditions on the properties of recycled poly(ethylene terephthalate)/nanoclay nanocomposites prepared by a twin-screw extruder

Journal of Applied Polymer Science ◽

10.1002/app.27280 ◽

2008 ◽

Vol 108 (4) ◽

pp. 2252-2259 ◽

Cited By ~ 29

Author(s):

A. L. F. de M. Giraldi ◽

M. T. M. Bizarria ◽

A. A. Silva ◽

J. I. Velasco ◽

Marcos A. d'Ávila ◽

...

Keyword(s):

Ethylene Terephthalate ◽

Twin Screw Extruder ◽

Screw Extruder ◽

Poly Ethylene Terephthalate ◽

Twin Screw ◽

Poly Ethylene

Download Full-text

Plasticized Biodegradable Poly(lactic acid) Based Composites Containing Cellulose in Micro- and Nanosize

Journal of Engineering ◽

10.1155/2013/329379 ◽

2013 ◽

Vol 2013 ◽

pp. 1-9 ◽

Cited By ~ 29

Author(s):

Katalin Halász ◽

Levente Csóka

Keyword(s):

Lactic Acid ◽

Microcrystalline Cellulose ◽

Composite Films ◽

Poly Lactic Acid ◽

Twin Screw Extrusion ◽

Scanning Calorimetry ◽

Screw Extrusion ◽

Twin Screw ◽

Biodegradable Poly ◽

Poly Ethylene

The aim of this work was to study the characteristics of thermal processed poly(lactic acid) composites. Poly(ethylene glycol) (PEG400), microcrystalline cellulose (MCC), and ultrasound-treated microcrystalline cellulose (USMCC) were used in 1, 3, and 5 weight percents to modify the attributes of PLA matrix. The composite films were produced by twin screw extrusion followed by film extrusion. The manufactured PLA-based films were characterized by tensile testing, differential scanning calorimetry (DSC), scanning electron microscopy (SEM), wide angle X-ray diffraction (WAXD), and degradation test.

Download Full-text

Investigation of Flame Retardant Properties of Poly(ethylene Terephthalate)/Silatrane Complex/Montmorillonite Nanocomposites

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.747.43 ◽

2013 ◽

Vol 747 ◽

pp. 43-46

Author(s):

Phawittra Sonsilchai ◽

Duangdao Aht-Ong

Keyword(s):

Mechanical Properties ◽

Flame Retardant ◽

Ethylene Terephthalate ◽

Synergistic Effects ◽

One Pot ◽

Poly Ethylene Terephthalate ◽

Twin Screw ◽

Ft Ir ◽

Flame Retardant Properties ◽

Poly Ethylene

Poly (ethylene terephthalate) or PET was used in many applications such as packagings, textiles, electrical devices, and auto parts as well due to its good mechanical properties and dimensional stabilities, etc. However, the main drawback of PET is poor flame retardant and melt-dripping, which needed to be solved. Therefore, the aim of this research was to improve the flame retardant properties of PET by investigating the synergistic effects of flame retardant agents between silatrane complex and montmorillonite (MMT) at various concentrations. Silatrane complex was synthesized from silica through one pot process. The characteristic of the obtained silatrane complex was determined by FT-IR, SEM, and TGA. Various ratios of PET/silatrane complex/MMT nanocomposites were prepared by melt bending using a twin screw extruder and compressed into standard shape according to ASTM standard by a compression molding, respectively. Morphology, flame retardant properties, and mechanical properties of PET nanocomposites were investigated. The flame retardant properties were evaluated by LOI values and UL-94V rating. The results showed that mechanical properties of PET/silatrane complex/MMT nanocomposites were slightly different from those of the neat PET. The flame retardant properties showed that the LOI values of PET/silatrane complex/MMT nanocomposites were greater than that of neat PET and increased with increasing the silatrane complex concentration. The LOI value of PET/7%silatrane/2%MMT nanocomposite was increased up to 60.75%, compared with that of neat PET. While neat PET was classified into V-2 rating since it showed sustainable burning and melt-dripping behavior during burning process, PET/silatrane complex/MMT nanocomposites did not show such behavior and thus could be designated as V-0 rating. In addition, the results indicated that the MMT could occur synergistic effect with silatrane complex as well.

Download Full-text

Effect of Impact Modifier on The Properties of Poly (Ethylene Terephthalate)-Organoclay Nanocomposites

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.334-335.649 ◽

2007 ◽

Vol 334-335 ◽

pp. 649-652

Author(s):

Ulku Yilmazer ◽

Elif Alyamac

Keyword(s):

Ethylene Terephthalate ◽

Shear Stresses ◽

Clay Particles ◽

Melt Compounding ◽

Poly Ethylene Terephthalate ◽

Twin Screw ◽

Impact Modifier ◽

Poly Ethylene ◽

Clay Layers ◽

The One

The effects of component concentrations and addition order of the components, on the final properties of ternary nanocomposites composed of amorphous poly (ethylene terephthalate) matrix, organically modified clay, and an ethylene / methyl acrylate / glycidyl methacrylate (E-MAGMA) terpolymer were studied. All formulations were prepared by melt compounding of the components with a two-step mixing procedure in a corotating twin-screw extruder. Considering the X-Ray Diffraction, SEM, impact and strain at break results, the best sequence of component addition was the one in which PET was first compounded with E-MA-GMA, later this mixture was compounded with the organoclay in a subsequent run. In this mixing order, the polymer-impact modifier matrix mixture prepared in the first extrusion run has higher melt viscosity than pure PET, thus this matrix can apply high shear stresses on the clay particles and delaminate the clay layers resulting in the best mechanical properties.

Download Full-text

Structure and Properties of Nanocomposites With a Poly(Ethylene Terephthalate) Matrix

Multifunctional Nanocomposites ◽

10.1115/mn2006-17087 ◽

2006 ◽

Author(s):

U. Gurmendi ◽

J. I. Eguiazabal ◽

J. Nazabal

Keyword(s):

Modulus Of Elasticity ◽

Ethylene Terephthalate ◽

Chemical Nature ◽

Clay Content ◽

High Dispersion ◽

Organic Modification ◽

Poly Ethylene Terephthalate ◽

The Matrix ◽

Twin Screw ◽

Poly Ethylene

Polymer nanocomposites based on poly(ethylene terephthalate) PET and with an intercalated and fairly dispersed nanostructure have been obtained in the melt state using a twin screw extruder. The intercalation and dispersion levels as well as the mechanical properties were studied varying the chemical nature and amount of the organic modification of the clay as well as the clay content. The intercalation level of PET into the organoclay galleries was measured by the increase in the interlayer distance upon mixing. The surfactant content did not influence the intercalation level but an interaction between the polymeric matrix and the surfactant, through a common polar character led to easier intercalation. The observed modulus increases and consequently the overall dispersion did not almost depend on either the amount or chemical nature of the used organic modification of the clay, suggesting that the parameters leading to high intercalation differ from those lead to a high modulus of elasticity and therefore to a high dispersion level. The obtained increases in the modulus of elasticity that reflect the dispersion level were large attaining a 41% increase with respect to that of the matrix after a 6wt% clay addition.

Download Full-text