Modification of Polylactic Acid (PLA) and its Industrial Applications

2020 ◽  
pp. 1-51
Author(s):  
A. Al-Mamun ◽  
M. Nikusahle ◽  
M. Feldmann ◽  
H.-P. Heim
Keyword(s):  
Polylactic Acid ◽  
Industrial Applications

scholarly journals Evaluation of the influence of design in the mechanical properties of honeycomb cores used in composite panels

2021 ◽  
pp. 146442072098519
Author(s):  
A Miranda ◽  
M Leite ◽  
L Reis ◽  
E Copin ◽  
MF Vaz ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Polylactic Acid ◽  
Failure Modes ◽  
Industrial Applications ◽  
Sandwich Composite ◽  
Composite Panels ◽  
Distribution Analysis ◽  
Absorbed Energy ◽  
Fused Filament Fabrication ◽  
Subtractive Manufacturing

The aerospace, automotive, and marine industries are heavily reliant on sandwich panels with cellular material cores. Although honeycombs with hexagonal cells are the most commonly used geometries as cores, recently there have been new alternatives in the design of lightweight structures. The present work aims to evaluate the mechanical properties of metallic and polymeric honeycomb structures, with configurations recently proposed and different in-plane orientations, produced by additive and subtractive manufacturing processes. Structures with configurations such as regular hexagonal honeycomb (Hr), lotus (Lt), and hexagonal honeycomb with Plateau borders (Pt), with 0°, 45°, and 90° orientations were analyzed. To evaluate its properties, three-point bending tests were performed, both experimentally and by numerical modeling, by means of the finite element method. Honeycombs of two aluminum alloys and polylactic acid were fabricated. The structures produced in aluminum were obtained either by selective laser melting technology or by machining, while polylactic acid structures were obtained by material extrusion using fused filament fabrication. From the stress distribution analysis and the load–displacement curves, it was possible to evaluate the strength, stiffness, and absorbed energy of the structures. Failure modes were also analyzed for polylactic acid honeycombs. In general, a strong correlation was observed between numerical and experimental results. The results show that the stiffness and absorbed energy increase in the order, Hr, Pt, Lt, and with the orientation through the sequence, 45°, 90°, 0°. Thus, Lt structures with 0° orientation seem to be good alternatives to the traditional honeycombs used in sandwich composite panels for those industrial applications where low weight, high stiffness, and large energy-absorbing capacity are required.

Sustainable composites: Processing of coir fibres and application in hybrid-fibre composites

2019 ◽  
Vol 54 (15) ◽  
pp. 1947-1960 ◽  
Author(s):  
Lucas Ciccarelli ◽  
Frederik Cloppenburg ◽  
Sangeetha Ramaswamy ◽  
Stepan V Lomov ◽  
Aart Van Vuure ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Polylactic Acid ◽  
High Performance ◽  
Industrial Applications ◽  
Coir Fibre ◽  
Hybrid Fibre ◽  
Fibre Composites ◽  
Composite Product ◽  
Composites Processing ◽  
Fibre Reinforced Composites

Coir fibres, a byproduct of the coconut industry, have high performance qualities but are difficult to process by conventional textile methods. The purpose of the research is to combine the processibility of hemp and flax with the high-performance properties of coir to create a composite product worthy of industrial applications. The evaluation of coir fibre-reinforced composites focuses on the processibility of the coir fibre into a nonwoven, how well it interfaces with polylactic acid and an analysis of how the mechanical properties of the final product change when mixing coir with hemp and flax. The results show that the hybrid samples outperformed most of the researched values for coir composites, despite the reduced properties of control samples as in comparable research. Adding just 10% of either flax or hemp dramatically increased the mechanical properties compared to the pure coir–polylactic acid composite.

scholarly journals Changes in Crystal Structure and Accelerated Hydrolytic Degradation of Polylactic Acid in High Humidity

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4324
Author(s):  
Yutaka Kobayashi ◽  
Tsubasa Ueda ◽  
Akira Ishigami ◽  
Hiroshi Ito
Keyword(s):  
Crystal Structure ◽  
Polylactic Acid ◽  
Hydrolytic Degradation ◽  
Gel Permeation Chromatography ◽  
Amorphous Region ◽  
Industrial Applications ◽  
Reduced Pressure ◽  
Specific Temperature ◽  
Time Changes ◽  
Random Scission

Highly crystallized polylactic acid (PLA) is suitable for industrial applications due to its stiffness, heat resistance, and dimensional stability. However, crystal lamellae in PLA products might delay PLA decomposition in the environment. This study clarifies how the initial crystal structure influences the hydrolytic degradation of PLA under accelerated conditions. Crystallized PLA was prepared by annealing amorphous PLA at a specific temperature under reduced pressure. Specimens with varied crystal structure were kept at 70 °C and in a relative humidity (RH) of 95% for a specific time. Changes in crystal structure were analyzed using differential calorimetry and wide-angle X-lay diffraction. The molecular weight (MW) was measured with gel permeation chromatography. The crystallinity of the amorphous PLA became the same as that of the initially annealed PLA within one hour at 70 °C and 95% RH. The MW of the amorphous PLA decreased faster even though the crystallinity was similar during the accelerated degradation. The low MW chains of the amorphous PLA tended to decrease faster, although changes in the MW distribution suggested random scission of the molecular chains for initially crystallized PLA. The concentrations of chain ends and impurities, which catalyze hydrolysis, in the amorphous region were considered to be different in the initial crystallization. The crystallinity alone does not determine the speed of hydrolysis.

scholarly journals A Review on Synthesis, Properties, and Applications of Polylactic Acid/Silica Composites

Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3036
Author(s):  
Mosab Kaseem ◽  
Zeeshan Ur Rehman ◽  
Shakhawat Hossain ◽  
Ashish Kumar Singh ◽  
Burak Dikici
Keyword(s):  
Polylactic Acid ◽  
Polymer Matrix ◽  
High Performance ◽  
In Situ Polymerization ◽  
Sol Gel ◽  
Industrial Applications ◽  
Melt Mixing ◽  
Silica Nanocomposites ◽  
Synthesis Properties ◽  
Potential Applications

Polylactic acid (PLA)/silica composites as multifunctional high-performance materials have been extensively examined in the past few years by virtue of their outstanding properties relative to neat PLA. The fabrication methods, such as melt-mixing, sol–gel, and in situ polymerization, as well as the surface functionalization of silica, used to improve the dispersion of silica in the polymer matrix are outlined. The rheological, thermal, mechanical, and biodegradation properties of PLA/silica nanocomposites are highlighted. The potential applications arising from the addition of silica nanoparticles into the PLA matrix are also described. Finally, we believe that a better understanding of the role of silica additive with current improvement strategies in the dispersion of this additive in the polymer matrix is the key for successful utilization of PLA/silica nanocomposites and to maximize their fit with industrial applications needs.

scholarly journals Polylactic Acid as a Potential Alternatives of Traditional Plastic Packagings in Food Industry

2020 ◽  
Vol 5 (2) ◽  
pp. 123-129
Author(s):  
Tibor Horváth ◽  
Tamás József Szabó ◽  
Kálmán Marossy
Keyword(s):  
Polylactic Acid ◽  
Food Industry ◽  
Physical And Mechanical Properties ◽  
Synthetic Polymers ◽  
Industrial Applications ◽  
Packaging Material ◽  
Application Area ◽  
Food Industries ◽  
Food Contact ◽  
The One

Huge quantity of synthetic polymers is used as packaging materials in different fields of food industries. A significant part of these polymers applied as a primary, direct food contact construction. The scoped application area is the sweet industry. In this field Polystyrol (PS), Polypropylene (PP) and Polyethylene terephthalate (PET) have used but during the last fifteen years the usage of PET has been grown. In one hand the price of this material is efficient, form other hand the PET is the one of the most safe (for food industrial applications) petrol chemical plastic that can be used as primary or secondary food contact packaging material. To maximize the customer safety and minimize the environmental impact of traditional PET, a new bio-sourced and bio-degradable alternative polymer aimed to be used in this special food industrial segment. One of the potential alternatives is the Polylactic acid (PLA) that would be a possible substitute as it is compostable and produced from renewable sources and has good physical and mechanical properties [1].

scholarly journals Valorization of Sugarcane Straw for the Development of Sustainable Biopolymer-Based Composites

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3335
Author(s):  
Jorge R. Robledo-Ortíz ◽  
Alan S. Martín del Campo ◽  
Juan A. Blackaller ◽  
Martín E. González-López ◽  
Aida A. Pérez Fonseca
Keyword(s):  
Tensile Strength ◽  
Impact Strength ◽  
Flexural Strength ◽  
Polylactic Acid ◽  
Industrial Waste ◽  
Tensile Modulus ◽  
Industrial Applications ◽  
Added Value ◽  
Sugarcane Straw ◽  
Filler Reinforcement

Sugarcane straw (SCS) is a common agro-industrial waste that is usually incinerated or discarded in fields after harvesting, increasing the importance of developing added-value applications for this residue. In this study, sustainable biocomposites were produced, and the effect of sugarcane straw as a filler/reinforcement of commercial biopolymers was evaluated. Biocomposites were prepared using polylactic acid (PLA), polyhydroxybutyrate (PHB), polyhydroxybutyrate-co-hydroxyvalerate (PHBV), or green polyethylene (Green-PE) with different fiber contents (20, 30, and 40 wt.%). Dry-blending followed by compression molding was used for the biocomposites preparation. The results showed that PLA, PHB, and PHBV biocomposites retained the same impact strength as the neat matrices, even with 40 wt.% of sugarcane straw. The flexural and tensile modulus of PLA, PHB, and PHBV biocomposites increased with 20% of SCS, whereas, in Green-PE biocomposites, these properties increased at all fiber contents. Since any compatibilizer was used, both the flexural and tensile strength decreased with the addition of SCS. However, even with the highest content of SCS, the tensile and flexural strength values were around 20 MPa, making these materials competitive for specific industrial applications.

Irradiation Induced Crosslinking in “Green” Polylactic-Acid (PLA) Polymers for Enhanced Strength and Elevated Temperature Applications

2020 ◽  
Author(s):  
W. Jiang ◽  
A. Bakken ◽  
R. P. Taleyarkhan
Keyword(s):  
High Temperature ◽  
Polylactic Acid ◽  
Chemical Engineering ◽  
Elevated Temperatures ◽  
Crosslinking Agent ◽  
Industrial Applications ◽  
Significant Loss ◽  
Crystalline Form ◽  
Photon Irradiation ◽  
Gamma Irradiated

Abstract This paper presents interdisciplinary (nuclear-mechanical-materials-chemical) engineering technology and results pertaining to use of ionization radiation for tailoring “green”, renewable corn-soy based amorphous and crystalline form polymers for use as low-to-high temperature adhesives. Both amorphous and crystalline form polymer forms of such the Polylactic-Acid (PLA) polymer were studied with and without photon irradiation, alongside with and without cross-linking agent. In order to study and enhance the high-temperature application of PLA as a novel, multi-purpose adhesive, small concentrations of the crosslinking agent triallyl isocyanurate (TAIC) were included into molten amorphous and semi-crystalline PLA cast as glue sticks, followed with Co-60 gamma-irradiation. Bond strength variations were studied in tensile mode at room temperature using the resulting adhesive in between two steel dowels (head-to-head bonded) as well as via shear strength testing at elevated temperatures (50–120°C) under a set pre-load of 222 N. It was found that gamma irradiated samples with TAIC exhibited noticeably improved bonding strength, and importantly, such strength can potentially prevail towards 100°C. These are exciting results which offer potential for application for building construction and safety enhancements especially under fires and similar accidents. Samples without TAIC exhibited significant loss of strength past 90°C. The full paper will discuss details of apparatus, modeling and simulation of irradiation dose delivery, testing protocols results, and future enhancements via hybrid neutron-photon-electron irradiation for utility in variety of industrial applications.

scholarly journals Mechanical and Structural Properties of Nanocarbon Particles Reinforced in Plasticised Polylactic Acid for High Strength Application

2021 ◽  
Vol 32 (2) ◽  
pp. 41-56
Author(s):  
Ajidasile Segun ◽  
Benjamin Omotayo Adewuyi ◽  
Daramola Oluyemi Ojo ◽  
Olaiya Niyi Gideon
Keyword(s):  
Diesel Engine ◽  
Mechanical Strength ◽  
Polylactic Acid ◽  
High Strength ◽  
Optical Microscope ◽  
Industrial Applications ◽  
Spare Parts ◽  
Morphological Properties ◽  
Compression Moulding ◽  
Engine Combustion

High strength application of biopolymers requires good mechanical strength. The tensile properties of polylactic acid (PLA) are relatively low for major industrial applications such as packaging, biomedical and automobile spare parts. In this study, the mechanical strength of polylactic acid was enhanced with nanocarbon isolated from diesel engine combustion soot. The isolated nanocarbon was characterised using spectrometry and Fourier transform infrared (FTIR) spectroscopy analysis. After that, the nanocarbon was used as a reinforcement in plasticised PLA to produce a composite. The PLA-nanocarbon composite was produced using the compression moulding technique. The nanocarbon composition was varied between 2 wt% and 8 wt% in the PLA matrix. The tensile, hardness and morphological properties of the composite were analysed with the tensile test, hardness test, optical microscope and X-ray diffraction (XRD) analysis. The ultraviolet (UV) spectrometer and FTIR analysis results confirmed the successful isolation of nanocarbon from the diesel engine combustion soot. The tensile and hardness properties of the PLA matrix increased with addition of nanocarbon. The morphological images showed good miscibility between the PLA and the nanocarbon reinforcement, responsible for the increase in mechanical properties. The potential use of the composite for high strength application showed great possibility based on the result obtained.

scholarly journals Areca Short Fiber Reinforced Polylactic Acid (PLA) Composites: Influence of Physical Treatment on Properties

2019 ◽  
Vol 8 (4) ◽  
pp. 3063-3072
Keyword(s):  
Surface Treatment ◽  
Polylactic Acid ◽  
Moisture Absorption ◽  
Dielectric Strength ◽  
Short Fiber ◽  
Industrial Applications ◽  
Physical Treatment ◽  
Fiber Loading ◽  
Biodegradable Composite ◽  
Mechanical Tensile

There is growing need to develop new biodegradable composite material which are eco-friendly and at the same time cater to the product application requirements. The research emphasis on study the properties of composites prepared by arbitrarily distributed UV treated areca fibers with Polylactic acid. Ultraviolet – a physical surface treatment has been carried out to treat areca short fibers which have been extracted from areca husk. Surface treatment significantly improves the bond between the fiber- matrix interface. The preparation of test samples has been performed using plain Polylactic acid, Polylactic acid - untreated areca short fiber (PLA-UnASF) and Polylactic acid - UV treated areca short fiber (PLA-TrASF) as per ASTM standards by means of injection moulding method. Varying fiber loading viz., 10%, 20%, 30% and 40% by weight have been utilized to develop test specimens. Developed composites have been portrayed for properties like density, moisture absorption, mechanical - tensile strength and modulus, flexural strength and modulus, izod impact strength, hardness, electrical - dielectric strength, thermal – TGA and DSC and soil degradation. The results indicate an improvement in strengths of composite with increase in fiber loading and physically treatment. This new material can be utilized for house hold appliances, automobiles and industrial applications.

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