The Effect of Nanosilicates on the Performance of Polyethylene Terephthalate Films Prepared by Twin-Screw Extrusion

2021 ◽  
Vol 36 (4) ◽  
pp. 358-366
Author(s):  
A. Ghanbari ◽  
M.-C. Heuzey ◽  
P. J. Carreau
Keyword(s):  
Electron Microscopy ◽  
Polyethylene Terephthalate ◽  
Tensile Modulus ◽  
Barrier Properties ◽  
Nucleating Agent ◽  
Morphological Characterization ◽  
Nanocomposite Films ◽  
Silicate Layer ◽  
Twin Screw ◽  
Pet Films

Abstract Polyethylene terephthalate (PET) films were prepared by cast extrusion using a twin-screw extruder with a severe screw profile. The effect of an organically modified montmorillonite on thermal, mechanical, optical, and barrier properties of the PET films were investigated. Morphological characterization of the nanocomposite films was performed by employing wide angle X-ray diffraction (WAXD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) followed by image analysis. The results unfold a mixed morphology for the nanocomposite films with more than 95% exfoliated and intercalated silicate layer structures, depending on the screw rotation speed. The remarkable dispersion of the organoclay particles at the nano-level is discussed in terms of solubility parameter and favorable interactions between PET macromolecules and organic modifier of the nanoclay. The crystal content of the nanocomposite films and their cold and hot crystallization temperatures confirmed the role of silicate nanolayers as a heterogeneous nucleating agent. While all nanocomposite films exhibit higher haze values in comparison to the neat PET samples, incorporation of 2 wt% nanoclay brought about 25% increase in tensile modulus and barrier properties. A range of screw rotation speeds with optimized properties in terms of haze, morphology, thermal, mechanical, and barrier properties is suggested.

scholarly journals A New Strategy for the Use of Post-Processing Vacuum Bags from Aerospace Supplies: Nucleating Agent to LLDPE Phase in PA6/LLDPE Blends

Recycling ◽  
2019 ◽  
Vol 4 (2) ◽  
pp. 18
Author(s):  
Gabriel Portilho Monteiro de Souza ◽  
Erick Gabriel Ribeiro dos Anjos ◽  
Larissa Stieven Montagna ◽  
Orestes Ferro ◽  
Fabio Roberto Passador
Keyword(s):  
Plastic Material ◽  
Low Cost ◽  
Barrier Properties ◽  
Nucleating Agent ◽  
Polyamide 6 ◽  
Morphological Characterization ◽  
Post Processing ◽  
Crystallinity Degree ◽  
New Strategy ◽  
Twin Screw

In the aerospace industry, many composite parts are manufactured by processes using plastic vacuum bags made of polyamide 6 (PA6) as a consumable material. This implies that after demolding the part, this plastic material should be discarded, generating a considerable amount of waste. Tons of vacuum bags are discarded and incinerated per month by several companies in this sector, which highlights the need to recycle and/or reuse this material. PA6/linear low-density polyethylene (LLDPE) blends are of great technological interest because they can combine the excellent thermo-mechanical and oxygen barrier properties of the PA6 with high impact strength, good processability, and low cost of LLDPE. The replacement of neat PA6 by the post-processing vacuum bags residue PA6 may be a new strategy for the recycling of this material. In this work, PA6/LLDPE/maleic anhydride-grafted LLDPE (LLDPE-g-MA) (90/5/5) blends were prepared using a co-rotational twin-screw extruder and the neat PA6 was replaced by different contents of post-processing PA6 (5, 10, 15 and 20 wt.%). The mechanical, thermal, and morphological characterization was evaluated. The increase in the content of post-processing PA6 caused an increase in the crystallinity degree of the LLDPE phase, acting as a nucleating agent to the LLDPE phase, reducing the toughening effect of this phase in the blends and, therefore, providing this phase to act as a reinforcing agent.

Crystallization Behavior of Polypropylene (PP)/ Polyethylene Terephthalate (PET) Composite Fibres

2008 ◽  
Vol 47-50 ◽  
pp. 833-836
Author(s):  
Dong Hui Liu ◽  
Xiao Juan Si ◽  
Jin Gao ◽  
Ling Ling Cao ◽  
Yi Min Wang
Keyword(s):  
Polyethylene Terephthalate ◽  
Differential Scanning Calorimeter ◽  
Crystallization Temperature ◽  
Crystallization Behavior ◽  
Nucleating Agent ◽  
Melting Behavior ◽  
Screw Extruder ◽  
Crystallization Peak ◽  
Twin Screw ◽  
Crystallization And Melting Behavior

Polypropylene (PP)/ polyethylene terephthalate (PET) composite fibres modified by PP-g-AA as a compatilizer were prepared by melt extrusion in a twin screw extruder. The crystallization and melting behavior of PP fibre and PP/PET composite fibres were investigated with differential scanning calorimeter (DSC)[1]. The results indicate that addition of PET acts as nucleating agent on the PP/PET composite fibres and increases the crystallization temperature of PP. [2,3]The crystallization peak temperature (Tp) increased first and decreased afterwards with the increase of PET, indicating that small amount of PET would promote the crystallization of PP, but excessive would reduce the crystallinity.

scholarly journals Effects of Modified Thermoplastic Starch on Crystallization Kinetics and Barrier Properties of PLA

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4125
Author(s):  
Apoorva Kulkarni ◽  
Ramani Narayan
Keyword(s):  
Crystallization Rate ◽  
Soxhlet Extraction ◽  
Barrier Properties ◽  
Reactive Extrusion ◽  
Nucleating Agent ◽  
Thermoplastic Starch ◽  
Aqueous Environment ◽  
Screw Extruder ◽  
Avrami Analysis ◽  
Twin Screw

This study reports on using reactive extrusion (REX) modified thermoplastic starch particles as a bio-based and biodegradable nucleating agent to increase the rate of crystallization, percent crystallinity and improve oxygen barrier properties while maintaining the biodegradability of PLA. Reactive blends of maleated thermoplastic starch (MTPS) and PLA were prepared using a ZSK-30 twin-screw extruder; 80% glycerol was grafted on the starch during the preparation of MTPS as determined by soxhlet extraction with acetone. The crystallinity of PLA was found to increase from 7.7% to 28.6% with 5% MTPS. The crystallization temperature of PLA reduced from 113 °C to 103 °C. Avrami analysis of the blends showed that the crystallization rate increased 98-fold and t1/2 was reduced drastically from 20 min to <1 min with the addition of 5% MTPS compared to neat PLA. Observation from POM confirmed that the presence of MTPS in the PLA matrix significantly increased the rate of formation and density of spherulites. Oxygen and water vapor permeabilities of the solvent-casted PLA/MTPS films were reduced by 33 and 19% respectively over neat PLA without causing any detrimental impacts on the mechanical properties (α = 0.05). The addition of MTPS to PLA did not impact the biodegradation of PLA in an aqueous environment.

scholarly journals Development of Sustainable and Cost-Competitive Injection-Molded Pieces of Partially Bio-Based Polyethylene Terephthalate through the Valorization of Cotton Textile Waste

2019 ◽  
Vol 20 (6) ◽  
pp. 1378 ◽  
Author(s):  
Sergi Montava-Jordà ◽  
Sergio Torres-Giner ◽  
Santiago Ferrandiz-Bou ◽  
Luis Quiles-Carrillo ◽  
Nestor Montanes
Keyword(s):  
Thermal Resistance ◽  
Polyethylene Terephthalate ◽  
Textile Industry ◽  
Food Packaging ◽  
Nucleating Agent ◽  
Short Fibers ◽  
Cotton Waste ◽  
Twin Screw ◽  
Injection Molded ◽  
Pet Crystallization

This study presents the valorization of cotton waste from the textile industry for the development of sustainable and cost-competitive biopolymer composites. The as-received linter of recycled cotton was first chopped to obtain short fibers, called recycled cotton fibers (RCFs), which were thereafter melt-compounded in a twin-screw extruder with partially bio-based polyethylene terephthalate (bio-PET) and shaped into pieces by injection molding. It was observed that the incorporation of RCF, in the 1–10 wt% range, successfully increased rigidity and hardness of bio-PET. However, particularly at the highest fiber contents, the ductility and toughness of the pieces were considerably impaired due to the poor interfacial adhesion of the fibers to the biopolyester matrix. Interestingly, RCF acted as an effective nucleating agent for the bio-PET crystallization and it also increased thermal resistance. In addition, the overall dimensional stability of the pieces was improved as a function of the fiber loading. Therefore, bio-PET pieces containing 3–5 wt% RCF presented very balanced properties in terms of mechanical strength, toughness, and thermal resistance. The resultant biopolymer composite pieces can be of interest in rigid food packaging and related applications, contributing positively to the optimization of the integrated biorefinery system design and also to the valorization of textile wastes.

Study on thermal and mechanical behaviors of polypropylene grade 552R/Cloisite 15A nanocomposites suitable for yarn applications

2021 ◽  
pp. 096739112110034
Author(s):  
Ali Farahani ◽  
Arsalan Parvareh ◽  
Mostafa Keshavarz Moraveji ◽  
Davood Soudbar
Keyword(s):  
Melt Spinning ◽  
Oxygen Index ◽  
Layer Structure ◽  
Tensile Modulus ◽  
Barrier Properties ◽  
Nucleating Agent ◽  
Clay Nanocomposites ◽  
Melt Mixing ◽  
Limiting Oxygen Index ◽  
Mixing Method

The investigation of polypropylene (PP)/clay nanocomposites has received considerable scientific and technological attention during the last decades due to their good mechanical and barrier properties. In the present article, the effects of adding Cloisite15A (C15A) nanoclay in polypropylene (PP) were investigated. PP nanocomposites were prepared by a direct melt mixing method. For better dispersion of C15A, 30 wt% of nanoclay masterbatch was first prepared by melt mixing of PP matrix and acrylic acid grafted PP oligomer (PP- g-AA) in a compounder, before being used to produce nanocomposites with 2 and 5 wt% of C15A. The aim of this work was to used nanoclay filled nanocomposites with suitable properties for cable application like good flame-retardant property; improve dye-ability and resilience of polypropylene. The XRD results indicated an intercalated layer structure for nanocomposites, The SEM examination showed satisfactory dispersion of nanoclay in 2 wt% of C15A and some degree of agglomeration in 5 wt% of C15A. DSC analysis indicated that C15A acts as a nucleating agent and increases crystallinity in the nanocomposite. TGA showed with increasing nanoclay, heat resistance was improved and degradation temperatures increased. Limiting oxygen index (LOI) tests showed increased flame retardancy from 25% for neat polypropylene t0 32.2% for nanocomposites of 5 wt% of C15A. The tensile modulus was improved from 423 MPa for neat polypropylene to 474 MPa for nanocomposites with 5 wt% of C15A. This result indicates that increasing C15A content had a suitable effect on the tensile properties. Melt spinning investigation on low oriented yarn (LOY), draw textured yarn (DTY), and fully drawn yarn (FDY) of 2 wt% C15A nanocomposite showed a reduction of linear density for FDY and an increase of the shrinkage. Furthermore, the obtained results for the improvement of dye-ability and compression resilience showed that PP/C15A is appropriate for textile products.

Preparation and characterization of biopolymer nanocomposites from cellulose nanofibrils and nanoclays

2017 ◽  
Vol 52 (5) ◽  
pp. 689-700 ◽  
Author(s):  
Gulyaz Al ◽  
Deniz Aydemir ◽  
Bulent Kaygin ◽  
Nadir Ayrilmis ◽  
Gokhan Gunduz
Keyword(s):  
Thermal Analysis ◽  
Polylactic Acid ◽  
Cellulose Nanofibrils ◽  
Tensile Modulus ◽  
Morphological Characterization ◽  
Morphological Properties ◽  
Screw Extruder ◽  
Twin Screw ◽  
Thermal Stability Of

The aim of this study was to investigate the effects of cellulose nanofibrils and nanoclays on the mechanical, thermal, and morphological properties of polyhydroxybutyrate and polylactic acid bio-polymers. Polyhydroxybutyrate and polylactic acid as a polymer matrix and nanoclays and cellulose nanofibrils as reinforcing nano-fillers were used to prepare the biopolymer nanocomposites in twin screw extruder. Density, flexure strength and flexure modulus, tensile strength and tensile modulus, impact strength, thermal properties, and morphological characterization of the obtained biopolymer nanocomposites were determined. According to the obtained results, densities of the biopolymer nanocomposites were found to decrease with addition of the bio-fillers, and it was determined to be decreasing the density due to increasing the porosity in biopolymer nanocomposites. Although the increasing in the porosity of biopolymer nanocomposites was found in scanning electron microscope pictures, the mechanical properties of the biopolymer nanocomposites generally increased as compare with neat bio-polymers. Thermal analysis conducted with thermogravimetric-dynamic thermal analysis and differential scanning calorimeter showed that thermal stability of the biopolymer nanocomposites generally improved according to the neat bio-polymers.

Morphology-Crystallinity Relationship in PLA-PHBV Blends Prepared via Extrusion

2013 ◽  
Vol 554-557 ◽  
pp. 1707-1714
Author(s):  
Alain Guinault ◽  
Gaelle Dutarte ◽  
Majdi Boufarguine ◽  
Guillaume Miquelard-Garnier ◽  
Cyrille Sollogoub
Keyword(s):  
Renewable Resources ◽  
Barrier Properties ◽  
Nucleating Agent ◽  
Extrusion Process ◽  
Poly Lactic Acid ◽  
Twin Screw Extrusion ◽  
Gas Barrier ◽  
Elongation At Break ◽  
Screw Extrusion ◽  
Twin Screw

Poly(lactic acid) (PLA) is a biodegradable thermoplastic polyester derived from renewable resources which may replace conventional polymers for some applications. To overcome some of its limitations such as poor gas barrier properties and low elongation at break, one method is to blend PLA with small amounts of other bio-based polymers. In this study, two processes, eg classical twin screw extrusion and a multilayer co-extrusion process have been used to combine PLA and poly(3-hydroxybutyrate-co-3-valerate) PHBV to obtain films with different blend morphologies. The effect of the morphology on the crystallinity has been studied and has hightlightned new behavior of PHBV. The addition of a nucleating agent in the PHBV to modify its crystallinity, has also been studied.

Barrier Properties Analysis of Polyethylene Terephthalate Films (PET) Coated with Natural Polyphenolic and Gelatin Mixture (PGM)

2018 ◽  
Vol 382 ◽  
pp. 38-43 ◽  
Author(s):  
Shagufta Ishtiaque ◽  
Shahina Naz ◽  
Jawaad Ahmed ◽  
Arshad Faruqui
Keyword(s):  
Polyethylene Terephthalate ◽  
Food Packaging ◽  
Oxygen Transfer Rate ◽  
Barrier Properties ◽  
Vapour Permeability ◽  
Barrier Materials ◽  
Oxygen Penetration ◽  
Green Tea Leaves ◽  
Film Formulation ◽  
Pet Films

The food packaging material provides protection against moisture, heat, enzymes, oxygen penetration etc. The shelf life of food can be increased by coating barrier materials on plastic films. In this work the oxygen transfer rate (OTR) and water vapour permeability (WVP) of Polyethylene terephthalate (PET) films were adjusted via coating of Polyphenols and Gelatin mixture (PGM) with different concentrations while maintaining the other properties of modified PET films. This article deals with the changes in properties of PGM coated PET films with some innovative ideas of multilayer film formulation. Polyphenolics were extracted from Terminalia Catappa (Indian almond), Camellia sinensis (Green tea leaves) and Trachyspermumammi (Ajwain). The results showed that WVP was decreased from 1.0±0 to 0.12±0.03 g/in2/day (p < 0.01) in comparison with uncoated (1.3±0.07g/in2/day). Similarly, same trend was obtained for OTR (63.5±0.02 to 38.1±0.03g/in2/day) with respect to uncoated film (82 ± 3.5). This study provides important evidence that addition of PGM on PET films leads to improved films in terms of OTR and WVP with minor changes in optical properties.

scholarly journals Preparation of PP/PP-g-MAH/C15A Nanocomposite by Melt Extrusion Process and Comparative Study of its Mechanical and Non-Isothermal Crystallization Behaviour

2021 ◽  
Vol 9 (VII) ◽  
pp. 3744-3757
Author(s):  
Rajesh Kumar Sahoo
Keyword(s):  
Nucleating Agent ◽  
Extrusion Process ◽  
Nanocomposite Films ◽  
Clay Particles ◽  
Clay Nanoparticles ◽  
Nucleation Effect ◽  
Blending Method ◽  
Organically Modified ◽  
Twin Screw ◽  
Clay Layers

Nanocomposite films have been prepared by melt blending method with the help of twin screw extruder using polymer polypropylene(PP)nucleating agent like organically modified nanoclay at optimum loading condition. Compatibilizers such as polypropylene grafted maleic anhydride (PP-g-MAH) were used for better compatibility between polymer matrix and filler. The effect of organoclay on nucleation effect and subsequent incremental values in mechanical and thermal behavior of different nanocomposite films has been investigated and explained with justifications. The tensile properties have shown to be improved in presence of clay nanoparticles due to resistance exerted by clay layers against plastic deformation of the polymer. Thermal properties measured by differential scanning calorimeter shows increased crystallization temperature of the nanocomposites in presence of clay particles and compatibilizer of optimum concentration.

scholarly journals Development of green MMT-modified hemicelluloses based nanocomposite film with enhanced functional and barrier properties

BioResources ◽  
2019 ◽  
Vol 14 (4) ◽  
pp. 8029-8047
Author(s):  
Kassim M. Haafiz ◽  
Owolabi F. A. Taiwo ◽  
Nadhilah Razak ◽  
Hashim Rokiah ◽  
Hussin M. Hazwan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Nanocomposite Film ◽  
Tensile Modulus ◽  
Water Vapor Permeability ◽  
Physical And Mechanical Properties ◽  
Barrier Properties ◽  
Nanocomposite Films ◽  
Vapor Permeability ◽  
Scanning Calorimetry

A biocomposite was successfully prepared by blending montmorillonite (MMT)/hemicellulose from oil palm empty fruit bunches (OPEFB) with carboxymethyl cellulose (CMC) through solution casting. The composite was characterized by scanning electron microscopy (SEM), Fourier transmission infrared spectroscopy (FT-IR), and X-ray diffraction (XRD). The results displayed good compatibility between the mixtures of the blended MMT/hemicellulose and CMC due to the hydrogen bonding and electrostatic interaction. There was an improvement in the thermal analysis through their thermogravimetry analysis (TGA), derivative thermogravimetry (DTG), and differential scanning calorimetry (DSC), mechanical properties (tensile strength and tensile modulus),and water vapor permeability (WVP). The best values of tensile strength and tensile modulus of 47.5 MPa and 2.62 MPa, respectively, were obtained from 60H-40CMC-MMT nanocomposite films. The results showed that the mixture of the blended MMT/hemicelluloses and CMC produced a robust nanocomposite film with improved physical and mechanical properties, demonstrating that it is a promising candidate for green packaging applications.

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