scholarly journals Extruded PLA Nanocomposites Modified by Graphene Oxide and Ionic Liquid

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 655
Author(s):  
Cristian Sánchez-Rodríguez ◽  
María-Dolores Avilés ◽  
Ramón Pamies ◽  
Francisco-José Carrión-Vilches ◽  
José Sanes ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Graphene Oxide ◽  
Viscoelastic Behavior ◽  
Mechanical Analysis ◽  
Twin Screw Extrusion ◽  
Scanning Calorimetry ◽  
Screw Extrusion ◽  
Ir And Raman Spectroscopies ◽  
Twin Screw ◽  
Ft Ir

Polylactic acid (PLA)-based nanocomposites were prepared by twin-screw extrusion. Graphene oxide (GO) and an ionic liquid (IL) were used as additives separately and simultaneously. The characterization of the samples was carried out by means of Fourier transform infrared (FT-IR) and Raman spectroscopies, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The viscoelastic behavior was determined using dynamic mechanical analysis (DMA) and rheological measurements. IL acted as internal lubricant increasing the mobility of PLA chains in the solid and rubbery states; however, the effect was less dominant when the composites were melted. When GO and IL were included, the viscosity of the nanocomposites at high temperatures presented a quasi-Newtonian behavior and, therefore, the processability of PLA was highly improved.

scholarly journals Bio-Based PBT–DLA Copolyester as an Alternative Compatibilizer of PP/PBT Blends

Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1421 ◽  
Author(s):  
Ignaczak ◽  
Sobolewski ◽  
El Fray
Keyword(s):  
Gel Permeation Chromatography ◽  
Mechanical Analysis ◽  
Resonance Spectroscopy ◽  
Twin Screw Extrusion ◽  
Scanning Calorimetry ◽  
Butylene Terephthalate ◽  
Screw Extrusion ◽  
Twin Screw ◽  
Static Tensile ◽  
Copolymer Poly

The aim of this work was to assess whether synthesized random copolyester, poly(butylene terephthalate-r-butylene dilinoleate) (PBT–DLA), containing bio-based components, can effectively compatibilize polypropylene/poly(butylene terephthalate) (PP/PBT) blends. For comparison, a commercial petrochemical triblock copolymer, poly(styrene-b-ethylene/butylene-b-styrene) (SEBS) was used. The chemical structure and block distribution of PBT–DLA was determined using nuclear magnetic resonance spectroscopy and gel permeation chromatography. PP/PBT blends with different mass ratios were prepared via twin-screw extrusion with 5 wt% of each compatibilizer. Thermogravimetric analysis, differential scanning calorimetry, and dynamic mechanical analysis were used to assess changes in phase structure of PP/PBT blends. Static tensile testing demonstrated marked improvement in elongation at break, to ~18% and ~21% for PBT–DLA and SEBS, respectively. Importantly, the morphology of PP/PBT blends compatibilized with PBT–DLA copolymer showed that it is able to act as interphase modifier, being preferentially located at the interface. Therefore, we conclude that by using polycondensation and monomers from renewable resources, it is possible to obtain copolymers that efficiently modify blend miscibility, offering an alternative to widely used, rubber-like petrochemical styrene compatibilizers.

Crystallization Behaviour of TiO2 Nanoparticle Reinforced Polypropylene

2010 ◽  
Vol 636-637 ◽  
pp. 688-696 ◽  
Author(s):  
Andreas Noll ◽  
Nicole Knoer
Keyword(s):  
Crystallization Behaviour ◽  
Structure Development ◽  
Twin Screw Extrusion ◽  
Scanning Calorimetry ◽  
Lamellar Structures ◽  
Screw Extrusion ◽  
Twin Screw ◽  
Wet Chemical ◽  
Wet Chemical Etching

Composites of isotactic polypropylene (iPP) with different TiO2 nanoparticle loads (0.5 vol.%, 2 vol.% and 4 vol.%) were compounded by optimized twin screw extrusion. The crystallization behaviour of these semicrystalline nanocomposites was examined by differential scanning calorimetry (DSC), scanning electron microscope (SEM) and polarized optical light microscope (POM) combined with a hot stage module to pursue in-situ the structure development. Wet chemical etching was applied to highlight morphological details like spherulites and lamellar structures for SEM observations. An obvious influence of TiO2-nanoparticles on the crystallization could be verified.

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

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
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.

Structural changes of polysaccharides isolated from corn bran by hydrothermal treatment after twin-screw extrusion

BioResources ◽  
2020 ◽  
Vol 15 (1) ◽  
pp. 1323-1337
Author(s):  
Hua-Min Liu ◽  
Ya-Nan Wei ◽  
Hao-Yang Li ◽  
An-Chi Wei ◽  
Xue-De Wang
Keyword(s):  
Hydrothermal Treatment ◽  
Structural Changes ◽  
Antioxidant Activities ◽  
Gel Permeation Chromatography ◽  
Twin Screw Extrusion ◽  
Corn Bran ◽  
Screw Extrusion ◽  
Twin Screw ◽  
Ft Ir ◽  
Physical Changes

The objective of this investigation was to elucidate the structural changes of the polysaccharides isolated by hydrothermal treatment of corn bran after twin-screw extrusion. The structures and antioxidant activities of the purified polysaccharides were investigated and compared by monosaccharide analysis, Fourier transform infrared (FT-IR), gel permeation chromatography (GPC), and nuclear magnetic resonance (NMR). The results showed that the structures of the linkages and monosaccharide components of the purified polysaccharides were not affected strongly by the twin-screw extrusion pretreatment. However, the purified polysaccharides isolated from pretreated samples displayed significant differences in monosaccharide ratios, degree of branching/ linearity, and molecular weight. These physical changes may be related to the decrease of antioxidant activities of the polysaccharides. The present investigation contributes to the knowledge of how pretreatment by twin-screw extrusion affects the chemistry of corn bran polysaccharides. Results can be applied to improve the efficiency of hydrothermal extraction of polysaccharides from corn bran.

scholarly journals Influence of the Conditions of Corotating Twin-Screw Extrusion for Talc-Filled Polypropylene on Selected Properties of the Extrudate

Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1460 ◽  
Author(s):  
Sasimowski ◽  
Majewski ◽  
Grochowicz
Keyword(s):  
Maximum Tensile Stress ◽  
Extrusion Process ◽  
Twin Screw Extrusion ◽  
Screw Extruder ◽  
Scanning Calorimetry ◽  
Melt Flow Rate ◽  
Test Segment ◽  
Screw Extrusion ◽  
Twin Screw

The aim of the study was to determine the effect of the application of processing screws with a modified test segment in a corotating twin-screw extruder on selected properties of talc-filled polypropylene extrudate. The test segment was built of trilobe kneading elements and its design modifications refered to changing the distance between the kneading elements and the angle of positions of kneading elements that are relative to each other. The performed tests included the production of extrudate with various degrees of talc-filling using five design solutions of the test segment and then measurements of selected properties, such as tensile strength, elongation at maximum tensile stress, and melt flow rate. Structural studies using scanning electron microscope (SEM) and differential scanning calorimetry (DSC) were also carried out. The study includes not only the description of experimental results but also the determination of empirical models describing the dependence of the properties of the obtained extrudate on the conditions of the extrusion process and the design features of the test segment.

The Effect of Poly(Butylene Adipate-co-Terephthalate) on Crystallization Behavior and Morphology of Poly(3-Hydroxybutyrate-co-3-Hydroxyvalerate)

2019 ◽  
Vol 798 ◽  
pp. 343-350
Author(s):  
Sitthi Duangphet ◽  
Damian Szegda ◽  
Karnik Tarverdi ◽  
Jim Song
Keyword(s):  
Crystal Structure ◽  
Crystallization Behavior ◽  
X Ray Diffraction ◽  
Twin Screw Extrusion ◽  
Scanning Calorimetry ◽  
Sem Images ◽  
X Ray ◽  
Screw Extrusion ◽  
Twin Screw ◽  
Matrix Morphology

The effects of poly(butylene adipate-co-terephthalate) (PBAT) on crystallization behavior and morphology of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) were studied to provide the useful information to control and improve PHBV processing. PHBV were blended with 15, 30 and 50 wt% PBAT by twin screw extrusion and these were subsequently compared to unblended PHBV. The rate of crystal development determined from differential scanning calorimetry (DSC) at 120 °C showed that the incorporation of PBAT retarded the crystal growth rate. Moreover, the crystal structure of polymer blends was examined by X-ray diffraction (XRD) and the results revealed that PBAT did not affect the crystal structure of PHBV. The responses of the melt-crystallized PHBV to different quantities of PBAT were recorded by polarized optical microscopy (POM). The results demonstrated that the size of spherulite dramatically increased when 15 wt% PBAT was added and the shape of spherulite was imperfect when PBAT reached 30 wt%. The morphologies of PHBV and its blends on the freeze-fractured specimens were exposed using scanning electron microscopy (SEM). The SEM images revealed the phase separation of PHBV/ PBAT blends in any composition. The morphology of 15 and 30 wt% PBAT presented droplet in matrix morphology and changed to co-continuous morphology at 50 wt% PBAT.

scholarly journals Extrusion of Polymer Nanocomposites with Graphene and Graphene Derivative Nanofillers: An Overview of Recent Developments

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 549 ◽  
Author(s):  
José Sanes ◽  
Cristian Sánchez ◽  
Ramón Pamies ◽  
María-Dolores Avilés ◽  
María-Dolores Bermúdez
Keyword(s):  
Graphene Oxide ◽  
Melt Processing ◽  
Alternative Methods ◽  
Processing Route ◽  
Twin Screw Extrusion ◽  
Manufacturing Method ◽  
Thermoplastic Matrix ◽  
Screw Extrusion ◽  
Twin Screw ◽  
Recent Developments

This review is focused on the recent developments of nanocomposite materials that combine a thermoplastic matrix with different forms of graphene or graphene oxide nanofillers. In all cases, the manufacturing method of the composite materials has been melt-processing, in particular, twin-screw extrusion, which can then be followed by injection molding. The advantages of this processing route with respect to other alternative methods will be highlighted. The results point to an increasing interest in biodegradable matrices such as polylactic acid (PLA) and graphene oxide or reduced graphene oxide, rather than graphene. The reasons for this will also be discussed.

scholarly journals High-Tribological-Performance Polymer Nanocomposites: An Approach Based on the Superlubricity State of the Graphene Oxide Agglomerates

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2237
Author(s):  
Eder H. C. Ferreira ◽  
Angela Aparecida Vieira ◽  
Lúcia Vieira ◽  
Guilhermino J. M. Fechine
Keyword(s):  
Graphene Oxide ◽  
High Viscosity ◽  
Tribological Performance ◽  
Multilayer Graphene ◽  
High Concentration ◽  
Scanning Calorimetry ◽  
Mechanical Reinforcement ◽  
Transmission Electron ◽  
Twin Screw ◽  
Mechanical Tensile

Here, nanocomposites of high-molecular-weight polyethylene (HMWPE) and HMWPE-UHMWPE (80/20 wt.%) containing a low amount of multilayer graphene oxide (mGO) (≤0.1 wt.%) were produced via twin-screw extrusion to produce materials with a higher tribological performance than UHMWPE. Due to the high viscosity of both polymers, the nanocomposites presented a significant concentration of agglomerates. However, the mechanical (tensile) and tribological (volumetric loss) performances of the nanocomposites were superior to those of UHMWPE. The morphology of the nanocomposites was investigated using differential scanning calorimetry (DSC), microtomography, and transmission electron microscopy (TEM). The explanation for these results is based on the superlubricity phenomenon of mGO agglomerates. It was also shown that the well-exfoliated mGO also contained in the nanocomposite was of fundamental importance as a mechanical reinforcement for the polymer. Even with a high concentration of agglomerates, the nanocomposites displayed tribological properties superior to UHMWPE’s (wear resistance up to 27% higher and friction coefficient up to 57% lower). Therefore, this manuscript brings a new exception to the rule, showing that agglomerates can act in a beneficial way to the mechanical properties of polymers, as long as the superlubricity phenomenon is present in the agglomerates contained in the polymer.

Sign in / Sign up

Export Citation Format

Share Document