scholarly journals Poly(Lactic Acid)-Based Nanobiocomposites with Modulated Degradation Rates

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1943 ◽  
Author(s):  
Iozzino Valentina ◽  
Askanian Haroutioun ◽  
Leroux Fabrice ◽  
Verney Vincent ◽  
Pantani Roberto
Keyword(s):  
Lactic Acid ◽  
Succinic Acid ◽  
Extrusion Process ◽  
Poly Lactic Acid ◽  
Melt Compounding ◽  
Degradation Rates ◽  
Rate Of Hydrolysis ◽  
Plastic Industry ◽  
Double Hydroxides ◽  
Kinetics Of

In the field of biodegradable polymers such as poly(Lactic Acid) (PLA), it is quite well known that their kinetics of hydrolysis strongly depend on the pH of the hydrolyzing medium. The idea explored during this study focused on PLA, is the addition of additives that are able to control the pH of water when it diffuses inside the polymer. For instance, acids (i.e. succinic acid, also used as food additive) are bio- and eco- friendly additives that are able to play this role. In order to control the release of these molecules and their dispersion inside the polymer, their intercalation in biocompatible nanofillers like layered double hydroxides (LDH) is here considered. The additives have been dispersed in the polymer by melt compounding, commonly used in the plastic industry. Several composites of PLA (4032D) and LDH intercalated with organic acids (succinic, fumaric, and ascorbic acid) have been obtained by an extrusion process. From all extruded materials, PLA films obtained by compression molding were then subjected to hydrolysis tests. The results showed that the mentioned molecules, dispersed in the polymer, are able to control the rate of hydrolysis, and experimental results show an increase of degradation time for samples containing LDH-organic acid (in particular with LDH-succinic acid), making such hybrid additives an appropriate and efficient solution for PLA.

scholarly journals Effect of Silane Functionalization on Properties of Poly(Lactic Acid)/Palygorskite Nanocomposites

Inorganics ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 3
Author(s):  
Anton Kasprzhitskii ◽  
Georgy Lazorenko ◽  
Alexander Kruglikov ◽  
Irina Kuchkina ◽  
Vadim Gorodov
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Polymer Matrix ◽  
Covalent Bond ◽  
Poly Lactic Acid ◽  
Hydroxyl Groups ◽  
Good Dispersion ◽  
Melt Compounding

Poly(lactic acid) (PLA)/palygorskite (Paly) nanocomposites were prepared using the melt compounding technique. Paly modified by 3-aminopropyltriethoxysilane (APTES) and vinyltrimethoxysilane (VTMS) was used as nanofiller for PLA with concentrations in the 1–7 wt% range. It has been found that the functionalization allows a covalent bond between the hydroxyl groups of the Paly and the PLA matrix, evidenced by the improvement in mechanical properties. Paly modification with VTMS has better properties compared with Pale modification with APTES. This indicates a better adhesion between the Paly-VTMS and PLA matrix, and a good dispersion of the nanofiller in the polymer matrix.

scholarly journals Hybrid Biocomposites Based on Poly(Lactic Acid) and Silica Aerogel for Food Packaging Applications

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4910 ◽  
Author(s):  
Alejandro Aragón-Gutierrez ◽  
Marina P. Arrieta ◽  
Mar López-González ◽  
Marta Fernández-García ◽  
Daniel López
Keyword(s):  
Thermal Stability ◽  
Lactic Acid ◽  
Silica Aerogel ◽  
Food Packaging ◽  
Mechanical Performance ◽  
Composite Films ◽  
Barrier Properties ◽  
Extrusion Process ◽  
Poly Lactic Acid ◽  
Barrier Performance

Bionanocomposites based on poly (lactic acid) (PLA) and silica aerogel (SiA) were developed by means of melt extrusion process. PLA-SiA composite films were plasticized with 15 wt.% of acetyl (tributyl citrate) (ATBC) to facilitate the PLA processability as well as to attain flexible polymeric formulations for films for food packaging purposes. Meanwhile, SiA was added in four different proportions (0.5, 1, 3 and 5 wt.%) to evaluate the ability of SiA to improve the thermal, mechanical, and barrier performance of the bionanocomposites. The mechanical performance, thermal stability as well as the barrier properties against different gases (carbon dioxide, nitrogen, and oxygen) of the bionanocomposites were evaluated. It was observed that the addition of 3 wt.% of SiA to the plasticized PLA-ATBC matrix showed simultaneously an improvement on the thermal stability as well as the mechanical and barrier performance of films. Finally, PLA-SiA film formulations were disintegrated in compost at the lab-scale level. The combination of ATBC and SiA sped up the disintegration of PLA matrix. Thus, the bionanocomposites produced here show great potential as sustainable polymeric formulations with interest in the food packaging sector.

scholarly journals Kinetics of Alkyl Lactate Formation from the Alcoholysis of Poly(Lactic Acid)

Processes ◽  
2020 ◽  
Vol 8 (6) ◽  
pp. 738
Author(s):  
Fabio M. Lamberti ◽  
Luis A. Román-Ramírez ◽  
Paul Mckeown ◽  
Matthew D. Jones ◽  
Joseph Wood
Keyword(s):  
Lactic Acid ◽  
Activation Energies ◽  
Poly Lactic Acid ◽  
Chemical Recycling ◽  
Green Solvents ◽  
Temperature Dependent ◽  
Exponential Factors ◽  
Autogenous Pressure ◽  
Lactate Formation ◽  
Kinetics Of

Alkyl lactates are green solvents that are successfully employed in several industries such as pharmaceutical, food and agricultural. They are considered prospective renewable substitutes for petroleum-derived solvents and the opportunity exists to obtain these valuable chemicals from the chemical recycling of waste poly(lactic acid). Alkyl lactates (ethyl lactate, propyl lactate and butyl lactate) were obtained from the catalysed alcoholysis reaction of poly(lactic acid) with the corresponding linear alcohol. Reactions were catalysed by a Zn complex synthesised from an ethylenediamine Schiff base. The reactions were studied in the 50–130 °C range depending on the alcohol, at autogenous pressure. Arrhenius temperature-dependent parameters (activation energies and pre-exponential factors) were estimated for the formation of the lactates. The activation energies (Ea1, Ea2 and Ea−2) for alcoholysis in ethanol were 62.58, 55.61 and 54.11 kJ/mol, respectively. Alcoholysis proceeded fastest in ethanol in comparison to propanol and butanol and reasonable rates can be achieved in temperatures as low as 50 °C. This is a promising reaction that could be used to recycle end-of-life poly(lactic acid) and could help create a circular production economy.

Effect of Compatibilizers on Composite Materials of Bio-Ethanol Byproduct-Poly(lacticacid)

2012 ◽  
Vol 204-208 ◽  
pp. 4088-4092
Author(s):  
Ming Ming Zhang ◽  
Xiao Huan Liu ◽  
Chun Peng Wang ◽  
Li Wei Jin
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Composite Materials ◽  
Extrusion Process ◽  
Poly Lactic Acid ◽  
Twin Screw Extrusion ◽  
Screw Extrusion ◽  
Twin Screw ◽  
Process Effects ◽  
Properties Of Composites

The blend composite materials of bio-ethanol byproduct-Poly(lactic acid) (PLA) were produced by a twin-screw extrusion process. Effects of bio-ethanol byproduct (BEB) contents and different compatibilizers on properties of composite materials were investigated. The research showed that with the increase of contents of bio-ethanol byproduct, the mechanical properties decreased. The mechanical properties of composites were improved by adding the compatibilizers, especially the polypropylene grafted maleic anhydride (PP-MAH). When the PP-MAH content was 2.5%, the mechanical properties of the composite materials were superior to others.

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