scholarly journals Orientation of Polylactic Acid–Chitin Nanocomposite Films via Combined Calendering and Uniaxial Drawing: Effect on Structure, Mechanical, and Thermal Properties

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3308
Author(s):  
Shikha Singh ◽  
Mitul Kumar Patel ◽  
Shiyu Geng ◽  
Anita Teleman ◽  
Natalia Herrera ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Properties ◽  
Solid State ◽  
Nanocomposite Films ◽  
Degree Of Crystallinity ◽  
Poly Lactic Acid ◽  
Mechanical And Thermal Properties ◽  
Orientation Factor ◽  
Crystallinity Degree ◽  
Positive Effects

The orientation of polymer composites is one way to increase the mechanical properties of the material in a desired direction. In this study, the aim was to orient chitin nanocrystal (ChNC)-reinforced poly(lactic acid) (PLA) nanocomposites by combining two techniques: calendering and solid-state drawing. The effect of orientation on thermal properties, crystallinity, degree of orientation, mechanical properties and microstructure was studied. The orientation affected the thermal and structural behavior of the nanocomposites. The degree of crystallinity increased from 8% for the isotropic compression-molded films to 53% for the nanocomposites drawn with the highest draw ratio. The wide-angle X-ray scattering results confirmed an orientation factor of 0.9 for the solid-state drawn nanocomposites. The mechanical properties of the oriented nanocomposite films were significantly improved by the orientation, and the pre-orientation achieved by film calendering showed very positive effects on solid-state drawn nanocomposites: The highest mechanical properties were achieved for pre-oriented nanocomposites. The stiffness increased from 2.3 to 4 GPa, the strength from 37 to 170 MPa, the elongation at break from 3 to 75%, and the work of fracture from 1 to 96 MJ/m3. This study demonstrates that the pre-orientation has positive effect on the orientation of the nanocomposites structure and that it is an extremely efficient means to produce films with high strength and toughness.

Influence of extrusion screw speed on the properties of halloysite nanotube impregnated polylactic acid nanocomposites

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Chaitra Venkatesh ◽  
Yuanyuan Chen ◽  
Zhi Cao ◽  
Shane Brennan ◽  
Ian Major ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Thermal Properties ◽  
Composite Films ◽  
Polymer Melt ◽  
Poly Lactic Acid ◽  
Mechanical And Thermal Properties ◽  
Screw Speed ◽  
Halloysite Nanotube ◽  
The Past

Abstract Poly (lactic acid)/halloysite nanotube (PLA/HNT) nanocomposites have been studied extensively over the past few years owing to the interesting properties of the polymer, PLA, and the nanoclay, HNT, individually and as composites. In this paper, the influence of the screw speed during extrusion was investigated and was found to have a significant impact on the mechanical and thermal performance of the extruded PLA/HNT nanocomposites. To determine the effect of screw speed on PLA/HNT nanocomposites, 5 and 10 wt% of HNTs were blended into the PLA matrix through compounding at screw speeds of 40, 80, and 140 rpm. Virgin PLA was compounded for comparison. The resultant polymer melt was quench cooled onto a calendar system to produce composite films which were assessed for mechanical, thermal, chemical, and surface properties. Results illustrate that in comparison to 40 and 80 rpm, the virgin PLA when compounded at 140 rpm, indicated a significant increase in the mechanical properties. The PLA/HNT 5 wt% nanocomposite compounded at 140 rpm showed significant improvement in the dispersion of HNTs in the PLA matrix which in turn enhanced the mechanical and thermal properties. This can be attributed to the increased melt shear at higher screw speeds.

scholarly journals Effect of Selected Commercial Plasticizers on Mechanical, Thermal, and Morphological Properties of Poly(3-hydroxybutyrate)/Poly(lactic acid)/Plasticizer Biodegradable Blends for Three-Dimensional (3D) Print

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1893 ◽  
Author(s):  
Přemysl Menčík ◽  
Radek Přikryl ◽  
Ivana Stehnová ◽  
Veronika Melčová ◽  
Soňa Kontárová ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Thermal Properties ◽  
Three Dimensional ◽  
Poly Lactic Acid ◽  
Mechanical And Thermal Properties ◽  
Modulated Differential Scanning Calorimetry ◽  
3D Print ◽  
3D Printed ◽  
Biodegradable Blends

This paper explores the influence of selected commercial plasticizers structure, which are based on esters of citric acid, on mechanical and thermal properties of Poly(3-hydroxybutyrate)/Poly(lactic acid)/Plasticizer biodegradable blends. These plasticizers were first tested with respect to their miscibility with Poly(3-hydroxybutyrate)/Poly(lactic acid) (PHB/PLA) blends using a kneading machine. PHB/PLA/plasticizer blends in the weight ratio (wt %) of 60/25/15 were then prepared by single screw and corotating meshing twin screw extruders in the form of filament for further three-dimensional (3D) printing. Mechanical, thermal properties, and shape stability (warping effect) of 3D printed products can be improved just by the addition of appropriate plasticizer to polymeric blend. The goal was to create new types of eco-friendly PHB/PLA/plasticizers blends and to highly improve the poor mechanical properties of neat PHB/PLA blends (with majority of PHB) by adding appropriate plasticizer. Mechanical properties of plasticized blends were then determined by the tensile test of 3D printed test samples (dogbones), as well as filaments. Measured elongation at break rapidly enhanced from 21% for neat non-plasticized PHB/PLA blends (reference) to 328% for best plasticized blends in the form of filament, and from 5% (reference) to 187% for plasticized blends in the form of printed dogbones. The plasticizing effect on blends was confirmed by Modulated Differential Scanning Calorimetry. The study of morphology was performed by the Scanning Electron Microscopy. Significant problem of plasticized blends used to be also plasticizer migration, therefore the diffusion of plasticizers from the blends after 15 days of exposition to 110 °C in the drying oven was investigated as their measured weight loss. Almost all of the used plasticizers showed meaningful positive softening effects, but the diffusion of plasticizers at 110 °C exposition was quite extensive. The determination of the degree of disintegration of selected plasticized blend when exposed to a laboratory-scale composting environment was executed to roughly check the “biodegradability”.

Mechanical and Thermal Properties of PLA Melt Blended with High Molecular Weight PEG Modified with Peroxide and Organo-Clay

2017 ◽  
Vol 751 ◽  
pp. 337-343 ◽  
Author(s):  
Chanchai Thongpina ◽  
Chaiwat Tippuwanan ◽  
Kwanchai Buaksuntear ◽  
Teerani Chuawittayawuta
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Molecular Weight ◽  
High Molecular Weight ◽  
Mechanical Performance ◽  
Organic Peroxide ◽  
Degree Of Crystallinity ◽  
Poly Lactic Acid ◽  
Mechanical And Thermal Properties ◽  
Cloisite 30B

The thermal and mechanical properties of poly (lactic acid) blended with high molecular weight PEG, i.e. PEG1000 and PEG6000 were compared. The contents of PEG added were 10, 12.5 and 15 % by weight, with respect to PLA. The PLA/PEG blends were modified by addition of organic peroxide in order to induced crosslinking. Addition of organic modified montmorrillonite (Cloisite 30B, C30B) was also performed in order to modify mechanical performance of PLA/PEG blends. C30B was prepared via master batch in PLA. Morphology, crystallization, thermal stability and mechanical properties of the blends were investigated using SEM, DSC, TGA and universal testing macine, respectively. Morphology of cryogenic fracture surface showed smooth brittle surface. PEG1000 well plasticized PLA where as PEG6000 shows better thermal stability and mechanical properties. The presence of PEG induced PLA to perform cold crystallization. Tm in PLA was slightly changed whereas degree of crystallinity of PLA was improved by PEG but slightly decreased by peroxide. The thermal stability of PLA was enhanced with the addtion of PEG6000. The toughening of PLA was confirmed by the increment of elongation at break. The exfoliation of C30B was interfered by the crosslink PLA. Then tensile strength of PLA/PEG/C30B/Luperox101 was then suppressed. The optimum properties, in term of toughening and thermal stability, were found at PEG content of 10 % rather than 15% by weight, for both PEG1000 and PEG6000.

scholarly journals Studies of properties of polypropylene/halloysite composites

2011 ◽  
Vol 13 (3) ◽  
pp. 61-65 ◽  
Author(s):  
Agnieszka Szczygielska ◽  
Jacek Kijeński
Keyword(s):  
Mechanical Properties ◽  
Thermal Properties ◽  
Polymer Composites ◽  
Degree Of Crystallinity ◽  
Mechanical And Thermal Properties ◽  
Thermal And Mechanical Properties ◽  
Polypropylene Composites ◽  
Modification Method ◽  
The Degree Of Crystallinity

Studies of properties of polypropylene/halloysite compositesThe results of the studies on the synthesis, mechanical and thermal properties of polypropylene composites with various amount of halloysite filler are presented. Halloysite (HNT) belongs to the silica type characterized by a two-layer 1:1 structure. This work was aimed to develop a method for the modification of halloysite in its prime use as a filler for polypropylene by extrusion. The composites contain 1, 3, 5 and 7 wt.% of HNT. The degree of crystallinity of the composites decrease with increasing halloysite content. The results confirm the expectations that composites of interesting physicochemical, mechanical and thermal properties can be obtained. The mechanical properties studied show that the filler modification method used leads to the synthesis of polymer composites of improved thermal and mechanical properties.

Effects of Processing Parameters and Nanofillers on Mechanical and Thermal Properties and Morphology of Impact Modified Poly (lactic acid)

2013 ◽  
Vol 1499 ◽  
Author(s):  
Eda Acik ◽  
Ulku Yilmazer
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Thermal Properties ◽  
Impact Strength ◽  
Random Copolymer ◽  
Processing Parameters ◽  
Poly Lactic Acid ◽  
Mechanical And Thermal Properties ◽  
Injection Molded ◽  
The Impact

ABSTRACTTernary nanocomposites of poly (lactic acid) (PLA) were produced by melt blending with two types of elastomers and five types of organoclays to obtain improved mechanical properties such as tensile strength, modulus and impact strength. One of the elastomers is a random copolymer of ethylene and glycidyl methacrylate (E-GMA) and the other one is a random terpolymer of ethylene-butyl acrylate-maleic anhydride (E-BA-MAH). Organically modified montmorillonites (OMMT) were utilized as nanofillers. XRD, DSC, tensile and impact tests were done on the injection molded samples. FTIR, SEM and TEM analyses are still in progress. As preliminary results, thermal analysis showed that the addition of compatibilizers and organoclays does not have a distinct effect on the thermal properties of the composites, and no evidence of nucleation activity of compatibilizers or organoclays was found. For all types of organoclays, the nanocomposites produced with E-GMA exhibited better mechanical properties in comparison to nanocomposites containing E-BA-MAH, especially for the impact strength.

Study on the Properties of Poly(lactic acid)/Starch/Chitosan Blended Materials

2011 ◽  
Vol 391-392 ◽  
pp. 530-534
Author(s):  
Peng Liu ◽  
Cai Qin Gu ◽  
Qing Zhu Zeng
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Thermal Properties ◽  
Tensile Modulus ◽  
Poly Lactic Acid ◽  
Mechanical And Thermal Properties ◽  
Carbonyl Groups ◽  
Amino Groups ◽  
Molecular Force ◽  
Hydroxy Groups

Former researchers have studied the properties of PLA/starch blended materials, but the influence of chitosan for them has not been studied yet. In this paper, it prepared the blended materials of PLA/starch/chitosan, and studied the compatible, mechanical and thermal properties of them. The results demonstrated that, since chitosan molecules had hydroxy and amino groups, which could form molecular force with the hydroxy groups in starch molecules and the carbonyl groups in PLA molecules respectively, the addition of it would improve the compatibility of PLA and starch. The SEM surface and section photos of blended materials could prove this compatibility, and the mechanical properties of blended materials also certified it. Specifically, with the addition of chitosan, the elongation, tensile modulus and tensile strength were all increase. For thermal properties, the addition of chitosan had no influence on it.

scholarly journals Investigation the effect of Graphene on The Morphology, Mechanical and Thermal properties of PLA/PMMA Blends

2015 ◽  
Vol 37 ◽  
pp. 15 ◽  
Author(s):  
Azin Paydayesh ◽  
Ahmad Aref Azar ◽  
Azam Jalali Arani
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Thermal Analysis ◽  
Thermal Properties ◽  
Poly Lactic Acid ◽  
Mechanical And Thermal Properties ◽  
Elongation At Break ◽  
Blend Morphology ◽  
Pmma Blends ◽  
Thermal Stability Of

In this work, Poly Lactic Acid/Poly methyl Methacrylate (PLA/PMMA) blends in various compositions prepared and morphology and properties of these blends was investigated. Moreover, the effect of adding different amounts of Graphene Nanoplatelets (GNP) on the morphology of the blends (by SEM), the interaction of nanopalates with polymer phases (by FTIR) and its effect on the mechanical properties and thermal stability of the samples were examined. The results of the study showed that in different amounts of graphene, these plates were preferentially located in the polymer phases dissimilarly and thus, caused the change of the blend morphology. In addition, measuring the mechanical properties by tensile test and results of thermal analysis by TGA indicated the improvement of thermal stability, modulus and mechanical strength and reduction of the elongation at break of graphene containing blends with increasing the loading of GNP. The changing behavior of the mechanical and thermal properties was proportional to the Graphene localization in blend phases.

scholarly journals Mechanical and thermal properties of PLA/halloysite bio-nanocomposite films: effect of halloysite nanoclay concentration and addition of glycerol

2017 ◽  
Vol 37 (4) ◽  
pp. 381-389 ◽  
Author(s):  
Siti Hajar Othman ◽  
Nurhafiqa Hassan ◽  
Rosnita A. Talib ◽  
Roseliza Kadir Basha ◽  
Nazratul Putri Risyon
Keyword(s):  
Mechanical Properties ◽  
Thermal Properties ◽  
Environmental Safety ◽  
Nanocomposite Films ◽  
Biodegradable Materials ◽  
Glass Temperature ◽  
Mechanical And Thermal Properties ◽  
Biodegradable Films ◽  
Elongation At Break ◽  
The Poor

Abstract The usage of biopolymers in developing biodegradable materials for applications that meet demands in society for sustainability and environmental safety has been limited due to the poor mechanical and thermal properties of biopolymers. This study aimed to improve the limited properties of biopolymers, particularly polylactic acid (PLA) films, by investigating the effect of incorporating different concentrations (0–5 wt.%) of halloysite nanoclay and by adding glycerol plasticiser on the mechanical properties (tensile strength, elongation at break, Young’s modulus, and toughness) and thermal properties (glass temperature (Tg), melting temperature (Tm), and crystalline temperature (Tc)) of the produced bio-nanocomposite films. It was found that the addition of halloysite nanoclay and glycerol improved the mechanical and thermal properties of the films. PLA films incorporated with 3 wt.% concentration of halloysite nanoclay resulted in optimum mechanical properties due to the uniform distribution or dispersion of halloysite nanoclay. The addition of halloysite nanoclay and glycerol reduced the Tg, Tm, and Tc of the films, suggesting that they can improve the processability of the biopolymer. The bio-nanocomposite films produced in this work have the potential to replace non-biodegradable films due to the improved properties of the films.

scholarly journals Printability, Mechanical and Thermal Properties of Poly(3-Hydroxybutyrate)-Poly(Lactic Acid)-Plasticizer Blends for Three-Dimensional (3D) Printing

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4736 ◽  
Author(s):  
Soňa Kontárová ◽  
Radek Přikryl ◽  
Veronika Melčová ◽  
Přemysl Menčík ◽  
Matyáš Horálek ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Thermal Properties ◽  
Three Dimensional ◽  
Poly Lactic Acid ◽  
Mechanical And Thermal Properties ◽  
Screw Extruder ◽  
Modulated Differential Scanning Calorimetry ◽  
Fused Deposition ◽  
3D Printed

This paper investigates the effect of plasticizer structure on especially the printability and mechanical and thermal properties of poly(3-hydroxybutyrate)-poly(lactic acid)-plasticizer biodegradable blends. Three plasticizers, acetyl tris(2-ethylhexyl) citrate, tris(2-ethylhexyl) citrate, and poly(ethylene glycol)bis(2-ethylhexanoate), were first checked whether they were miscible with poly(3-hydroxybutyrate)-poly(lactic acid) (PHB-PLA) blends using a kneading machine. PHB-PLA-plasticizer blends of 60-25-15 (wt.%) were then prepared using a corotating meshing twin-screw extruder, and a single screw extruder was used for filament preparation for further three-dimensional (3D) fused deposition modeling (FDM) printing. These innovative eco-friendly PHB-PLA-plasticizer blends were created with a majority of PHB, and therefore, poor mechanical properties and thermal properties of neat PHB-PLA blends were improved by adding appropriate plasticizer. The plasticizer also influences the printability of blends, which was investigated, based on our new specific printability tests developed for the optimization of printing conditions (especially printing temperature). Three-dimensional printed test samples were used for heat deflection temperature measurements and Charpy and tensile-impact tests. Plasticizer migration was also investigated. The macrostructure of 3D printed samples was observed using an optical microscope to check the printing quality and printing conditions. Tensile tests of 3D printed samples (dogbones), as well as extruded filaments, showed that measured elongation at break raised, from 21% for non-plasticized PHB-PLA reference blends to 84% for some plasticized blends in the form of filaments and from 10% (reference) to 32% for plasticized blends in the form of printed dogbones. Measurements of thermal properties (using modulated differential scanning calorimetry and oscillation rheometry) also confirmed the plasticizing effect on blends. The thermal and mechanical properties of PHB-PLA blends were improved by the addition of appropriate plasticizer. In contrast, the printability of the PHB-PLA reference seems to be slightly better than the printability of the plasticized blends.

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