The Influence of Kaolin Clay on the Mechanical Properties and Structure of Thermoplastic Starch Films

The aim of study was to investigate the influence of kaolin on the physical properties and utility of film produced from native starch. The work involved measurements of strength, structure, and thermal properties. The films were prepared by the casting method. Composite films with 0%, 5%, 10%, and 15% kaolin additives were examined. Measurements of mechanical properties were carried out using the uniaxial tensile test, the nanoindentation test, and nanoscratching. Surface properties were examined by atomic force microscopy and contact angle measurements. Structure was determined by the X-ray diffraction method, and thermal properties were determined by differential scanning calorimetry. A significant influence of kaolin on the strength parameters and thermal and barrier properties of composite films was found. An increase in kaolin content reduced the tensile strength, Young’s modulus, and Poisson’s ratio. Structural analysis showed a partial intercalation and the layered arrangement of kaolin particles. Kaolin additives increased the barrier properties of water vapor in composite films of about 9%. Biopolymer modification by nanoclay reduced the thermal stability of composite films by 7% and could accelerate the biodegradation process. Increasing the concentration of kaolin in the biopolymer matrix led to heightened surface roughness (approximately 64%) and wettability of the surfaces of the film composites of 58%.

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The Influence of Sub-Zero Conditions on the Mechanical Properties of Polylactide-Based Composites

Materials ◽

10.3390/ma13245789 ◽

2020 ◽

Vol 13 (24) ◽

pp. 5789

Author(s):

Olga Mysiukiewicz ◽

Mateusz Barczewski ◽

Arkadiusz Kloziński

Keyword(s):

Mechanical Properties ◽

Room Temperature ◽

Mechanical Performance ◽

Mechanical Analysis ◽

Uniaxial Tensile ◽

Uniaxial Tensile Test ◽

Mechanical And Thermal Properties ◽

Scanning Calorimetry ◽

Linseed Cake ◽

Static Mechanical

Polylactide-based composites filled with waste fillers due to their sustainability are a subject of many current papers, in which their structural, mechanical, and thermal properties are evaluated. However, few studies focus on their behavior in low temperatures. In this paper, dynamic and quasi-static mechanical properties of polylactide-based composites filled with 10 wt% of linseed cake (a by-product of mechanical oil extraction from linseed) were evaluated at room temperature and at −40 °C by means of dynamic mechanical analysis (DMA), Charpy’s impact strength test and uniaxial tensile test. It was found that the effect of plasticization provided by the oil contained in the filler at room temperature is significantly reduced in sub-zero conditions due to solidification of the oil around −18 °C, as it was shown by differential scanning calorimetry (DSC) and DMA, but the overall mechanical performance of the polylactide-based composites was sufficient to enable their use in low-temperature applications.

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Design of Novel PLA/OMMT Films with Improved Gas Barrier and Mechanical Properties by Intercalating OMMT Interlayer with High Gas Barrier Polymers

Polymers ◽

10.3390/polym13223962 ◽

2021 ◽

Vol 13 (22) ◽

pp. 3962

Author(s):

Abdul Shakoor Shar ◽

Caili Zhang ◽

Xieqing Song ◽

Yunxuan Weng ◽

Qiuyue Du

Keyword(s):

Mechanical Properties ◽

Vinyl Alcohol ◽

Composite Films ◽

Barrier Properties ◽

Poly Vinyl Alcohol ◽

Diffraction Measurement ◽

Scanning Calorimetry ◽

Gas Barrier ◽

Ethylene Vinyl Alcohol ◽

Barrier Polymers

Polymer/clay composites are an innovative class of materials. In this study, we present a facile method for the preparation of biodegradable and robust PLA/organomodified montmorillonite (OMMT) composite films with excellent gas barrier performance. When the design of PLA/OMMT composite films, in addition to making OMMT have good intercalation effect in the matrix, the compatibility of intercalating polymer and matrix should also be considered. In this work, two polymers with high gas barrier properties, namely poly(vinyl alcohol) (PVA) and ethylene vinyl alcohol copolymer (EVOH), were selected to intercalate OMMT. The morphology and microstructures of the prepared PLA/PVA/OMMT and PLA/EVOH/OMMT composites were characterized by the X-ray diffraction measurement, scanning electron microscopy, and differential scanning calorimetry. It was shown that the good dispersibility of PVA in the PLA matrix, rather than the intercalation effect, was responsible for the improved gas barrier and mechanical properties of PLA/PVA/OMMT composite. The elongation at break increases from 4.5% to 22.7% when 1 wt % PVA is added to PLA/OMMT. Moreover, gas barrier of PLA/PVA1/OMMT measured as O2 permeability is 52.8% higher than that of neat PLA. This work provides a route to intercalate OMMT interlayer with high gas barrier polymers and thus can be a useful reference to fabricate PLA/OMMT composites with improved gas barrier and mechanical properties. A comparison of oxygen permeabilities with existing commercial packaging films indicates that the biodegradable PLA/PVA/OMMT may serve as a viable substitute for packaging film applications.

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Effect of the Biodegradable Compounds Composition with Monoglycerides on Mechanical Properties

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1031.7 ◽

2021 ◽

Vol 1031 ◽

pp. 7-16

Author(s):

Ilya Vasilyev ◽

Vladimir Ananiev ◽

Yulia Sultanova ◽

Valentina Kolpakova

Keyword(s):

Mechanical Properties ◽

Hybrid Composite ◽

Composite Films ◽

Thermoplastic Starch ◽

Test Methods ◽

Rheological Parameters ◽

Rice Starch ◽

Scanning Calorimetry ◽

Cost Efficient ◽

Distilled Monoglycerides

The purpose of this work is to improve the production technology of biodegradable hybrid compositions based on low-density polyethylene with thermoplastic starch and new plasticizer–distilled monoglyceride and determination of the composition effect on mechanical properties. Starch was plasticized with a mixture of glycerol and distilled monoglycerides, instead of the known sorbitol. This article describes methods for producing biodegradable hybrid composite films based on polyethylene and thermoplastic starches (corn, pea and rice) with a mass ratio of components, respectively, 40:60÷60:40 and their mechanical properties. Properties and structure of composite films are studied using test methods, rheological parameters, optical microscopy, and differential scanning calorimetry. The advantages of using monoglycerides as a plasticizer in thermoplastic starch/ polyethylene compositions have been demonstrated. Composites obtained using distilled monoglycerides and thermoplastic corn, pea and rice starch have been characterized by 62-81% higher values of critical stress and 62-93% elongation at rupture, compared with BHC containing sorbitol. The thickness of biodegradable hybrid composite films with monoglycerides is 55-86% less than that of films containing sorbitol in composition of thermoplastic starch. Higher elongation values at rupture and lower film thickness will ensure more effective destruction in environment and more cost-efficient use in packaging.

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Effect of the talc filler on structural, water vapor barrier and mechanical properties of poly(lactic acid) composites

Journal of Polymer Engineering ◽

10.1515/polyeng-2015-0014 ◽

2016 ◽

Vol 36 (2) ◽

pp. 181-188 ◽

Cited By ~ 5

Author(s):

Aleksandra Buzarovska ◽

Gordana Bogoeva-Gaceva ◽

Radek Fajgar

Keyword(s):

Mechanical Properties ◽

Lactic Acid ◽

Water Vapor ◽

Composite Films ◽

Water Vapor Permeability ◽

Barrier Properties ◽

Poly Lactic Acid ◽

Vapor Permeability ◽

Scanning Calorimetry ◽

Structural Water

Abstract Poly(lactic acid) (PLA) based composite films with different content of talc (5–15 wt%) were prepared by the solvent casting method. The effect of talc on morphological, structural, thermal, barrier and mechanical properties of neat PLA was investigated. The PLA/talc composites revealed a polymorphic crystalline structure, as demonstrated by X-ray diffraction (XRD) study and differential scanning calorimetry (DSC) analysis. The PLA/talc composites also exhibited significantly improved barrier properties (up to 55% compared to neat PLA), as shown by water vapor permeability (WVP) tests. The puncture measurements showed improved mechanical properties at lower content of talc (up to 5 wt%), and increased brittleness of the PLA/talc composite films at higher talc concentrations.

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Experimental and Numerical Evaluation of Mechanical Properties of 3D-Printed Stainless Steel 316L Lattice Structures

Journal of Materials Engineering and Performance ◽

10.1007/s11665-021-05737-w ◽

2021 ◽

Author(s):

M. Carraturo ◽

G. Alaimo ◽

S. Marconi ◽

E. Negrello ◽

E. Sgambitterra ◽

...

Keyword(s):

Mechanical Properties ◽

Stainless Steel ◽

Mechanical Behavior ◽

Numerical Simulations ◽

Uniaxial Tensile ◽

Uniaxial Tensile Test ◽

Lattice Structures ◽

Stainless Steel 316L ◽

Research Attention ◽

Octet Truss

AbstractAdditive manufacturing (AM), and in particular selective laser melting (SLM) technology, allows to produce structural components made of lattice structures. These kinds of structures have received a lot of research attention over recent years due to their capacity to generate easy-to-manufacture and lightweight components with enhanced mechanical properties. Despite a large amount of work available in the literature, the prediction of the mechanical behavior of lattice structures is still an open issue for researchers. Numerical simulations can help to better understand the mechanical behavior of such a kind of structure without undergoing long and expensive experimental campaigns. In this work, we compare numerical and experimental results of a uniaxial tensile test for stainless steel 316L octet-truss lattice specimen. Numerical simulations are based on both the nominal as-designed geometry and the as-build geometry obtained through the analysis of µ-CT images. We find that the use of the as-build geometry is fundamental for an accurate prediction of the mechanical behavior of lattice structures.

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Effect of PWHT on the Microstructure and Mechanical Properties of Friction Stir Welded DP780 Steel

Metals ◽

10.3390/met11071097 ◽

2021 ◽

Vol 11 (7) ◽

pp. 1097

Author(s):

Umer Masood Chaudry ◽

Seung-Chang Han ◽

Fathia Alkelae ◽

Tea-Sung Jun

Keyword(s):

Mechanical Properties ◽

Annealing Temperature ◽

Tensile Elongation ◽

Image Correlation ◽

Frictional Heat ◽

Uniaxial Tensile ◽

Uniaxial Tensile Test ◽

Friction Stir ◽

Microstructure And Mechanical Properties ◽

Dp780 Steel

In the present study, the effect of post-weld heat treatment (PWHT) on the microstructure and mechanical properties of friction stir welded (FSW) DP780 steel sheets was investigated. FSW was carried out at a constant tool rotation speed of 400 rpm and different welding speeds (200 mm/min and 400 min/min). A defect free weld was witnessed for both of the welding conditions. The mutual effect of severe plastic deformation and frictional heat generation by pin rotation during the FSW process resulted in grain refinement due to dynamic recrystallization in the stir zone (SZ) and thermo-mechanically affected zone (TMAZ). Lower tensile elongation and higher yield and ultimate tensile strengths were recorded for welded-samples as compared to the base material (BM) DP780 steel. The joints were subsequently annealed at various temperatures at 450–650 °C for 1 h. At higher annealing temperature, the work hardening rate of joints gradually decreased and subsequently failed in the softened heat-affected zone (HAZ) during the uniaxial tensile test. Reduction in yield strength and tensile strength was found in all PWHT conditions, though improvement in elongation was achieved by annealing at 550 °C. The digital image correlation analysis showed that an inhomogeneous strain distribution occurred in the FSWed samples, and the strain was particularly highly localized in the advancing side of interface zone. The nanoindentation measurements covering the FSWed joint were consistent with an increase of the annealing temperature. The various grains size in the BM, TMAZ, and SZ is the main factor monitoring the hardness distribution in these zones and the observed discrepancies in mechanical properties.

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Ecofriendly Preparation and Characterization of a Cassava Starch/Polybutylene Adipate Terephthalate Film

Processes ◽

10.3390/pr8030329 ◽

2020 ◽

Vol 8 (3) ◽

pp. 329

Author(s):

Tan Yi ◽

Minghui Qi ◽

Qi Mo ◽

Lijie Huang ◽

Hanyu Zhao ◽

...

Keyword(s):

Mechanical Properties ◽

Contact Angle ◽

Water Vapor ◽

Composite Film ◽

Water Absorption ◽

Composite Films ◽

Thermoplastic Starch ◽

Light Transmittance ◽

Infrared Spectrometry ◽

Nano Zno

Composite films of polybutylene adipate terephthalate (PBAT) were prepared by adding thermoplastic starch (TPS) (TPS/PBAT) and nano-zinc oxide (nano-ZnO) (TPS/PBAT/nano-ZnO). The changes of surface morphology, thermal properties, crystal types and functional groups of starch during plasticization were analyzed by scanning electron microscopy, synchronous thermal analysis, X-ray diffraction, infrared spectrometry, mechanical property tests, and contact Angle and transmittance tests. The relationship between the addition of TPS and the tensile strength, transmittance, contact angle, water absorption, and water vapor barrier of the composite film, and the influence of nano-ZnO on the mechanical properties and contact angle of the 10% TPS/PBAT composite film. Experimental results show that, after plasticizing, the crystalline form of starch changed from A-type to V-type, the functional group changed and the lipophilicity increased; the increase of TPS content, the light transmittance and mechanical properties of the composite membrane decreased, while the water vapor transmittance and water absorption increased. The mechanical properties of the composite can be significantly improved by adding nano-ZnO at a lower concentration (optimum content is 1 wt%).

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Enhancing the Thermal and Mechanical Characteristics of Polyvinyl Alcohol (PVA)-Hemp Protein Particles (HPP) Composites

International Polymer Processing ◽

10.1515/ipp-2020-3974 ◽

2021 ◽

Vol 36 (2) ◽

pp. 137-143

Author(s):

S. A. Awad

Keyword(s):

Mechanical Properties ◽

Elevated Temperatures ◽

Composite Films ◽

Tensile Tests ◽

Mechanical Analysis ◽

Decomposition Temperature ◽

Scanning Calorimetry ◽

Solution Casting Method ◽

Protein Particles

Abstract This paper aims to describe the thermal, mechanical, and surface properties of a PVA/HPP blend whereby the film was prepared using a solution casting method. The improvements in thermal and mechanical properties of HPP-based PVA composites were investigated. The characterization of pure PVA and PVA composite films included tensile tests, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The results of TGA and DSC indicated that the addition of HPP increased the thermal decomposition temperature of the composites. Mechanical properties are significantly improved in PVA/HPP composites. The thermal stability of the PVA composite increased with the increase of HPP filler content. The tensile strength increased from 15.74 ± 0.72 MPa to 27.54 ± 0.45 MPa and the Young’s modulus increased from 282.51 ± 20.56 MPa to 988.69 ± 42.64 MPa for the 12 wt% HPP doped sample. Dynamic mechanical analysis (DMA) revealed that at elevated temperatures, enhanced mechanical properties because of the presence of HPP was even more noticeable. Morphological observations displayed no signs of agglomeration of HPP fillers even in composites with high HPP loading.

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Effect of High Pressure Treatment on Poly(lactic acid)/Nano–TiO2 Composite Films

Molecules ◽

10.3390/molecules23102621 ◽

2018 ◽

Vol 23 (10) ◽

pp. 2621 ◽

Cited By ~ 3

Author(s):

Hai Chi ◽

Wenhui Li ◽

Chunli Fan ◽

Cheng Zhang ◽

Lin Li ◽

...

Keyword(s):

Mechanical Properties ◽

High Pressure ◽

Lactic Acid ◽

Composite Film ◽

Composite Films ◽

Barrier Properties ◽

Poly Lactic Acid ◽

Pressure Treatment ◽

Nano Tio2 ◽

High Pressure Treatment

The microstructure, thermal properties, mechanical properties and oxygen and water vapor barrier properties of a poly(lactic acid) (PLA)/nano-TiO2 composite film before and after high pressure treatment were studied. Structural analysis showed that the functional group structure of the high pressure treated composite film did not change. It was found that the high pressure treatment did not form new chemical bonds between the nanoparticles and the PLA. The micro-section of the composite film after high pressure treatment became very rough, and the structure was depressed. Through the analysis of thermal and mechanical properties, high pressure treatment can not only increase the strength and stiffness of the composite film, but also increase the crystallinity of the composite film. Through the analysis of barrier properties, it is found that the barrier properties of composite films after high pressure treatment were been improved by the applied high pressure treatment.

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The influence of adding long basalt fiber on the mechanical and thermal properties of composites based on poly(oxymethylene)

Journal of Thermoplastic Composite Materials ◽

10.1177/0892705718806549 ◽

2018 ◽

Vol 33 (4) ◽

pp. 435-450 ◽

Cited By ~ 4

Author(s):

Patrycja Bazan ◽

Stanisław Kuciel ◽

Mariola Sądej

Keyword(s):

Mechanical Properties ◽

Thermal Properties ◽

Average Length ◽

Flexural Modulus ◽

Basalt Fiber ◽

Charpy Impact ◽

Mechanical And Thermal Properties ◽

Gravimetric Analysis ◽

Scanning Calorimetry ◽

Atr Spectroscopy

The work has evaluated the possibility of the potential reinforcing of poly(oxymethylene) (POM) by basalt fibers (BFs) and influence of BFs addition on thermal properties. Two types of composites were produced by injection molding. There were 20 and 40 wt% long BFs content with an average length of 1 mm. The samples were made without using a compatibilizer. In the experimental part, the basic mechanical properties (tensile strength, modulus of elasticity, strain at break, flexural modulus, flexural strength, and deflection at 3.5% strain) of composites based on POM were determined. Tensile properties were also evaluated at three temperatures −20°C, 20°C, and 80°C. The density and Charpy impact of the produced composites were also examined. The influence of water absorption on mechanical properties was investigated. Thermal properties were conducted by the differential scanning calorimetry, thermal gravimetric analysis, and fourier transform infrared (FTIR)-attenuation total reflection (ATR) spectroscopy analysis. In order to make reference to the effects of reinforcement and determine the structure characteristics, scanning electron microscopy images were taken. The addition of 20 and 40 wt% by weight of fibers increases the strength and the stiffness of such composites by more than 30–70% in the range scale of temperature. Manufactured composites show higher thermal and dimensional stability in relation to neat POM.

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