Incorporation of an antibiotic in poly(lactic acid) and polypropylene by melt processing

2016 ◽  
Vol 14 (3) ◽  
pp. 0-0 ◽  
Author(s):  
Roberto Scaffaro ◽  
Luigi Botta ◽  
Andrea Maio ◽  
Giuseppe Gallo
Keyword(s):  
Lactic Acid ◽  
Melt Processing ◽  
Poly Lactic Acid

Thermal degradation kinetics of Opuntia Ficus Indica flour and talc-filled poly (lactic acid) hybrid biocomposites by TGA analysis

2021 ◽  
pp. 002199832110082
Author(s):  
Azzeddine Gharsallah ◽  
Abdelheq Layachi ◽  
Ali Louaer ◽  
Hamid Satha
Keyword(s):  
Thermal Stability ◽  
Lactic Acid ◽  
Thermal Degradation ◽  
Degradation Kinetics ◽  
Degradation Mechanism ◽  
Melt Processing ◽  
Thermal Degradation Kinetics ◽  
Poly Lactic Acid ◽  
Opuntia Ficus Indica ◽  
Model Free

This paper reports the effect of lignocellulosic flour and talc powder on the thermal degradation behavior of poly (lactic acid) (PLA) by thermogravimetric analysis (TGA). Lignocellulosic flour was obtained by grinding Opuntia Ficus Indica cladodes. PLA/talc/ Opuntia Ficus Indica flour (OFI-F) biocomposites were prepared by melt processing and characterized using Wide-angle X-ray scattering (WAXS) and Scanning Electron Microscope (SEM). The thermal degradation of neat PLA and its biocomposites can be identified quantitatively by solid-state kinetics models. Thermal degradation results on biocomposites compared to neat PLA show that talc particles at 10 wt % into the PLA matrix have a minor impact on the thermal stability of biocomposites. Loading OFI-F and Talc/OFI-F mixture into the PLA matrix results in a decrease in the maximum degradation temperature, which means that the biocomposites have lower thermal stability. The activation energies (Ea) calculated by the Flynn Wall Ozawa (FWO) and Kissinger Akahira Sunose (KAS) model-free approaches and by model-fitting (Kissinger method and Coats-Redfern method) are in good agreement with one another. In addition, in this work, the degradation mechanism of biocomposites is proposed using Coats-Redfern and Criado methods.

scholarly journals A Review on Barrier Properties of Poly(Lactic Acid)/Clay Nanocomposites

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1095 ◽  
Author(s):  
Shuvra Singha ◽  
Mikael S. Hedenqvist
Keyword(s):  
Lactic Acid ◽  
Mass Transport ◽  
Food Packaging ◽  
In Situ Polymerization ◽  
Barrier Properties ◽  
Melt Processing ◽  
Effective Length ◽  
Poly Lactic Acid ◽  
Clay Nanocomposites ◽  
Solution Intercalation

Poly(lactic acid) (PLA) is considered to be among the best biopolymer substitutes for the existing petroleum-based polymers in the field of food packaging owing to its renewability, biodegradability, non-toxicity and mechanical properties. However, PLA displays only moderate barrier properties to gases, vapors and organic compounds, which can limit its application as a packaging material. Hence, it becomes essential to understand the mass transport properties of PLA and address the transport challenges. Significant improvements in the barrier properties can be achieved by incorporating two-dimensional clay nanofillers, the planes of which create tortuosity to the diffusing molecules, thereby increasing the effective length of the diffusion path. This article reviews the literature on barrier properties of PLA/clay nanocomposites. The important PLA/clay nanocomposite preparation techniques, such as solution intercalation, melt processing and in situ polymerization, are outlined followed by an extensive account of barrier performance of nanocomposites drawn from the literature. Fundamentals of mass transport phenomena and the factors affecting mass transport are also presented. Furthermore, mathematical models that have been proposed/used to predict the permeability in polymer/clay nanocomposites are reviewed and the extent to which the models are validated in PLA/clay composites is discussed.

scholarly journals Influence of melt processing conditions on poly(lactic acid) degradation: Molar mass distribution and crystallization

2014 ◽  
Vol 110 ◽  
pp. 353-363 ◽  
Author(s):  
Pierre Erwan Le Marec ◽  
Laurent Ferry ◽  
Jean-Christophe Quantin ◽  
Jean-Charles Bénézet ◽  
Frédéric Bonfils ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Mass Distribution ◽  
Molar Mass ◽  
Melt Processing ◽  
Molar Mass Distribution ◽  
Poly Lactic Acid ◽  
Processing Conditions ◽  
Acid Degradation

scholarly journals Improving Recycled Poly(lactic Acid) Biopolymer Properties by Chain Extension Using Block Copolymers Synthesized by Nitroxide-Mediated Polymerization (NMP)

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2791
Author(s):  
Juan José Benvenuta-Tapia ◽  
Pascale Champagne ◽  
José Alfredo Tenorio-López ◽  
Eduardo Vivaldo-Lima ◽  
Ramiro Guerrero-Santos
Keyword(s):  
Lactic Acid ◽  
Block Copolymers ◽  
Molar Mass ◽  
Average Molecular Weight ◽  
Melt Processing ◽  
Cold Crystallization ◽  
Chain Extension ◽  
Poly Lactic Acid ◽  
Chain Extenders ◽  
Nitroxide Mediated Polymerization

The aim of this contribution is to assess the use poly(styrene-co-glycidyl methacrylate-b-styrene) copolymers synthesized by nitroxide mediated polymerization (NMP) as chain extenders in the recycling of poly(lactic acid) biopolyester. Concisely, the addition of such block copolymers during the melt processing of recycled poly(lactic acid) (rPLA) leads to important increases in the viscosity average molecular weight of modified polymeric materials. Molar masses increase from 31,000 g/mol for rPLA to 48,000 g mol−1 for the resulting rPLA/copolymer blends (bPLA). Fortuitously, this last value is nearly the same as the one for pristine PLA, which constitutes a first piece of evidence of the molar mass increase of the recycled biopolymer. Thermograms of chain extended rPLA show significant decreases in cold crystallization temperature and higher crystallinity degrees due to the chain extension process using NMP-synthesized copolymers. It was found that increasing epoxide content in the NMP-synthesized copolymers leads to increased degrees of crystallinity and lower cold crystallization temperatures. The rheological appraisal has shown that the addition of NMP synthesized copolymers markedly increases complex viscosity and elastic modulus of rPLA. Our results indicate that P(S-co-GMA)-b-S) copolymers act as efficient chain extenders of rPLA, likely due to the reaction between the epoxy groups present in P(S-co-GMA)-b-PS and the carboxyl acid groups present in rPLA. This reaction positively affects viscometric molar mass of PLA and its performance.

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