Valorization of poly(lactic acid) wastes via mechanical recycling: Improvement of the properties of the recycled polymer

2018 ◽  
Vol 37 (2) ◽  
pp. 135-141 ◽  
Author(s):  
F.R. Beltrán ◽  
I. Barrio ◽  
V. Lorenzo ◽  
B. del Río ◽  
J. Martínez Urreaga ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Food Packaging ◽  
Fossil Fuel ◽  
Chain Extender ◽  
Poly Lactic Acid ◽  
Recycling Process ◽  
Mechanical Recycling ◽  
Improved Performance ◽  
Recycled Polymer ◽  
Recycled Material

Poly(lactic acid) (PLA) is a biobased polymer that represents one of the most interesting alternatives to fossil-fuel based polymers in food packaging applications. Most of the PLA used in food packaging is used only once and then discarded, even though the PLA types used in packaging have good properties and stability. Therefore, it seems reasonable to consider the possibility of recycling the used polymer through a mechanical recycling process. The main aims of this work are to study the effect of the mechanical recycling on the properties of PLA and the usefulness of different upgrading methods to obtain recycled PLA with improved properties. A commercial type of PLA was subjected to accelerated thermal, photochemical and hydrolytic aging and then reprocessed. During reprocessing, aged PLA was blended with virgin PLA and a commercial chain extender was added. Results point out that recycling causes the degradation of PLA, and negatively affects the thermal stability and mechanical properties. However, addition of virgin PLA, and the chain extender, led to an increase of up to 9% in the intrinsic viscosity and 8% in the Vickers hardness of the recycled material. These results suggest that mechanically recycled PLA with improved performance can be obtained, a fact which might improve the recyclability of PLA and thus the environmental impact of this material.

scholarly journals Development of Eco-Sustainable PBAT-Based Blown Films and Performance Analysis for Food Packaging Applications

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5395
Author(s):  
Arianna Pietrosanto ◽  
Paola Scarfato ◽  
Luciano Di Maio ◽  
Loredana Incarnato
Keyword(s):  
Food Packaging ◽  
Mechanical Response ◽  
Chain Extender ◽  
Poly Lactic Acid ◽  
Blown Films ◽  
Beneficial Effects ◽  
Flexible Packaging ◽  
Improved Performance ◽  
And Performance ◽  
Good Transparency

In this work, eco-sustainable blown films with improved performance, suitable for flexible packaging applications requiring high ductility, were developed and characterized. Films were made by blending two bioplastics with complementary properties—the ductile and flexible poly(butylene-adipate-co-terephthalate) (PBAT) and the rigid and brittle poly(lactic acid) (PLA)—at a 60/40 mass ratio. With the aim of improving the blends’ performance, the effects of two types of PLA, differing for viscosity and stereoregularity, and the addition of a commercial polymer chain extender (Joncryl®), were analyzed. The use of the PLA with a viscosity ratio closer to PBAT and lower stereoregularity led to a finer morphology and better interfacial adhesion between the phases, and the addition of the chain extender further reduced the size of the dispersed phase domains, with beneficial effects on the mechanical response of the produced films. The best system composition, made by the blend of PBAT, amorphous PLA, and the compatibilizer, proved to have improved mechanical properties, with a good balance between stiffness and ductility and also good transparency and sealability, which are desirable features for flexible packaging applications.

Mechanical recycling of poly(lactic acid): Evaluation of a chain extender and a peroxide as additives for upgrading the recycled plastic.

2019 ◽  
Vol 219 ◽  
pp. 46-56 ◽  
Author(s):  
Freddys R. Beltrán ◽  
Celia Infante ◽  
Ma Ulagares de la Orden ◽  
Joaquín Martínez Urreaga
Keyword(s):  
Lactic Acid ◽  
Chain Extender ◽  
Poly Lactic Acid ◽  
Mechanical Recycling ◽  
A Chain

scholarly journals Optimisation on Thermoforming of Biodegradable Poly (Lactic Acid) (PLA) by Numerical Modelling

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 654
Author(s):  
Huidong Wei
Keyword(s):  
Lactic Acid ◽  
Numerical Modelling ◽  
Temperature Profile ◽  
Food Packaging ◽  
Strong Dependence ◽  
Viscoelastic Model ◽  
Poly Lactic Acid ◽  
Strain History ◽  
Optimal Temperature ◽  
Broad Perspective

Poly (lactic acid) (PLA) has a broad perspective for manufacturing green thermoplastic products by thermoforming for its biodegradable properties. The mechanical behaviour of PLA has been demonstrated by its strong dependence on temperature and strain rate at biaxial deformation. A nonlinear viscoelastic model by the previous study was employed in a thermoforming process used for food packaging. An optimisation approach was developed by achieving the optimal temperature profile of specimens by defining multiple heating zones based on numerical modelling with finite element analysis (FEA). The forming process of a PLA product was illustrated by modelling results on shape evolution and biaxial strain history. The optimal temperature profile was suggested in scalloped zones to achieve more even thickness distribution. The sensitivity of the optimal results was addressed by checking the robustness under perturbation.

Effect of a chain extender on the properties of poly(lactic acid)/zinc oxide/copper chlorophyll acid antibacterial nanocomposites

2014 ◽  
pp. n/a-n/a ◽  
Author(s):  
Weihua Fan ◽  
Yue Zhao ◽  
Aijing Zhang ◽  
Yukun Liu ◽  
Yanxia Cao ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Lactic Acid ◽  
Chain Extender ◽  
Poly Lactic Acid ◽  
A Chain

Sustainable Active Food Packaging from Poly(lactic acid) and Cocoa Bean Shells

2019 ◽  
Vol 11 (34) ◽  
pp. 31317-31327 ◽  
Author(s):  
Evie L. Papadopoulou ◽  
Uttam C. Paul ◽  
Thi Nga Tran ◽  
Giulia Suarato ◽  
Luca Ceseracciu ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Food Packaging ◽  
Poly Lactic Acid ◽  
Cocoa Bean ◽  
Active Food Packaging

Enhanced properties of poly(lactic acid) by concurrent addition of organo-modified Mg-Al layered double hydroxide (LDH) and triethyl citrate

2019 ◽  
pp. 089270571986827 ◽  
Author(s):  
Mehrnoush Monshizadeh ◽  
Sajad Seifi ◽  
Iman Hejazi ◽  
Javad Seyfi ◽  
Hossein Ali Khonakdar
Keyword(s):  
Lactic Acid ◽  
Layered Double Hydroxide ◽  
Food Packaging ◽  
Synergistic Effects ◽  
Poly Lactic Acid ◽  
Solution Casting ◽  
Scanning Calorimetry ◽  
Concurrent Use ◽  
Triethyl Citrate ◽  
Double Hydroxide

Synergistic effects of organo-modified Mg-Al layered double hydroxide (LDH) and triethyl citrate (TEC) on the properties of poly(lactic acid) (PLA) were demonstrated. PLA/LDH nanocomposites in the absence and presence of TEC were fabricated via solution casting technique. Morphological analysis revealed that as the LDH concentration increases, the number of aggregations is also increased; however, introduction of TEC considerably enhanced the dispersion quality of LDHs. Differential scanning calorimetry results showed that the addition of LDH and TEC had no significant influence on the crystallinity of nanocomposites obtained from solution casting. In contrast, once the samples were cooled from melt, the concurrent use of LDH and TEC led to a dramatic enhancement in the crystallinity of PLA ( X c = 55.5%). Moreover, the LDH nanoparticles counterbalanced the adverse effects of plasticization by TEC leading to enhanced toughness of the final nanocomposites. LDH had also a positive influence on thermal stability of PLA, indicating the heat-insulating role of LDH particles. In conclusion, the concurrent use of LDH and TEC could extend the applicability of PLA especially in food packaging applications.

scholarly journals Release of Graphene and Carbon Nanotubes from Biodegradable Poly(Lactic Acid) Films during Degradation and Combustion: Risk Associated with the End-of-Life of Nanocomposite Food Packaging Materials

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2346 ◽  
Author(s):  
Stanislav Kotsilkov ◽  
Evgeni Ivanov ◽  
Nikolay Vitanov
Keyword(s):  
Risk Assessment ◽  
Carbon Nanotubes ◽  
Lactic Acid ◽  
Food Packaging ◽  
Safety Concern ◽  
Barrier Properties ◽  
Nanocomposite Films ◽  
Poly Lactic Acid ◽  
Qualitative Risk Assessment ◽  
The Matrix

Nanoparticles of graphene and carbon nanotubes are attractive materials for the improvement of mechanical and barrier properties and for the functionality of biodegradable polymers for packaging applications. However, the increase of the manufacture and consumption increases the probability of exposure of humans and the environment to such nanomaterials; this brings up questions about the risks of nanomaterials, since they can be toxic. For a risk assessment, it is crucial to know whether airborne nanoparticles of graphene and carbon nanotubes can be released from nanocomposites into the environment at their end-life, or whether they remain embedded in the matrix. In this work, the release of graphene and carbon nanotubes from the poly(lactic) acid nanocomposite films were studied for the scenarios of: (i) biodegradation of the matrix polymer at the disposal of wastes; and (ii) combustion and fire of nanocomposite wastes. Thermogravimetric analysis in air atmosphere, transmission electron microscopy (TEM), atomic force microscopy (AFM) and scanning electron microscope (SEM) were used to verify the release of nanoparticles from nanocomposite films. The three factors model was applied for the quantitative and qualitative risk assessment of the release of graphene and carbon nanotubes from nanocomposite wastes for these scenarios. Safety concern is discussed in respect to the existing regulations for nanowaste stream.

Response of Modified Poly(lactic acid) to Microwave Radiation

2012 ◽  
Vol 488-489 ◽  
pp. 1393-1397
Author(s):  
Buranin Saengiet ◽  
Wasin Koosomsuan ◽  
Phassakarn Paungprasert ◽  
Rattikarn Khankrua ◽  
Sumonman Naimlang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Microwave Radiation ◽  
Food Packaging ◽  
Impact Resistance ◽  
Poly Lactic Acid ◽  
Polypropylene Glycol ◽  
Heat Accumulation ◽  
The One ◽  
Internal Mixer

The frozen instant food packaging is the one of disposal product, which produced from petroleum–based plastic and has been accumulated worldwide pressuring on the environment. Therefore, the biodegradable plastics have become key candidates in this application. Poly(lactic acid) (PLA) was regarded as one of the most promising biodegradable polymer due to its good mechanical properties. The aim of this work was to study on the freezability and microwavability of PLA through crosslink reaction. For the improvement of the processibility of PLA, hyperbranched polymer (HBP) and polypropylene glycol (PPG) were used as plasticizer. Then the crosslinking of PLA was introduced by addition of peroxide (Luperox101) and triallyl isocyanurate (TAIC) in an internal mixer. Neat and modified PLA samples were characterized and testing for mechanical properties. From the gel content results, it was showed the increased value with the increased content of TAIC due to the denser crosslinked structure of polymer. This result was confirmed by FT-IR spectra. All modified PLA samples showed the higher %strain at break than neat PLA. In addition, impact resistance in frozen state showed the results of modified PLA with 0.1wt% of peroxide and 0.15 wt% of TAIC, was higher than neat PLA. Moreover, this composition also showed the highest microwave response and heat accumulation was suppressed when the specimen was immersed in the water during the test. From the results obtained in this work, the further investigation is needed to pursue and elucidate the relationship between the polymer structure and heat absorption when materials undergo the microwave radiation.

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