Thermomechanical properties of alumina-filled plasticized polylactic acid: Effect of alumina loading percentage

Polylactic acid (PLA) can be a good alternative to petroleum-based polymers thanks to its organic origin and its biodegradability. This study introduces some promising routes for enhancing the processability of PLA, which presents several challenges due mainly to the poor shear and elongation properties of this biopolymer. To our knowledge, this is the first paper dedicated to an investigation of foaming and/or blown extrusion of PLA that focuses on structural, rheological and thermomechanical properties. Two main routes were selected: (i) the modification of its structural, rheological and thermomechanical properties and (ii) blending the PLA with another ductile, thermoplastic biopolymer such as poly (butylene adipate-co-terephthalate) (PBAT) or polyamide (PA11). Various formulations of PLA with multifunctionalized epoxy, nucleating agents and plasticizer were prepared and characterized on the basis of their linear viscoelasticity and extensional properties. The balance of chain extension and branching was also investigated using solution viscosimetry, steric exclusion chromatography (SEC) and rheology (shear and elongation rheology). On one hand, a batch foaming process assisted by supercritical CO2 was carried out. The influence of the foaming parameters, the extent of chain modification and the contribution of crystallization to cell morphology were all evaluated. Based on these parameters, structures ranging from micro to macro-cellular-cell were obtained. On the other hand, the stability maps of blown extrusion for neat and modified PLA were established at different die temperatures. We succeeded in greatly enhancing the blown extrusion windows of PLA, achieving high blow-up ratio (BUR) and take-up ratio (TUR) values. We were able to demonstrate that faster kinetics of crystallization can also be reached for chain-extended and branched PLA formulated with adequate amounts of nucleating agents and plasticizers. Through this work, blown films with intriguing thermomechanical and mechanical properties were produced using an optimal formulation for PLA.

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Anaerobic Codigestion of Food Waste and Polylactic Acid: Effect of Pretreatment on Methane Yield and Solid Reduction

Advances in Materials Science and Engineering ◽

10.1155/2019/4715904 ◽

2019 ◽

Vol 2019 ◽

pp. 1-6 ◽

Cited By ~ 2

Author(s):

Shakira R. Hobbs ◽

Prathap Parameswaran ◽

Barbara Astmann ◽

Jay P. Devkota ◽

Amy E. Landis

Keyword(s):

Anaerobic Digestion ◽

Polylactic Acid ◽

Food Waste ◽

Alkaline Treatment ◽

Alkaline Pretreatment ◽

Digested Sludge ◽

Acid Effect ◽

Anaerobic Codigestion ◽

Methane Potential ◽

Set Up

Food waste and biopolymers, plastics derived from plants, are unexploited sources of energy when discarded in landfills without energy recovery. In addition, polylactic acid (PLA) and food waste have complimentary characteristics for anaerobic digestion; both are organic and degrade under anaerobic conditions. Lab-scale reactors were set up to quantify the solubilization of pretreated amorphous and crystalline PLA. Biochemical methane potential (BMP) assays were performed to quantify CH4 production from both treated and untreated PLA in the presence of food waste and anaerobic digested sludge. Amorphous and crystalline PLA reached near-complete solubilization at 97% and 99%, respectively, when alkaline pretreatment was applied. The PLA that received alkaline treatment produced the most of CH4 throughout the run time of 70 days. The PLA without treatment resulted in 54% weight reduction after anaerobic digestion. Results from this study show that alkaline pretreatment has the greatest solid reduction of PLA and maximum production of CH4 when combined with food waste and anaerobic digested sludge.

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Degradation and stability of green composites fabricated from oil palm empty fruit bunch fiber and polylactic acid: Effect of fiber length

Journal of Composite Materials ◽

10.1177/0021998314560219 ◽

2014 ◽

Vol 49 (25) ◽

pp. 3103-3114 ◽

Cited By ~ 6

Author(s):

AKM Moshiul Alam ◽

MDH Beg ◽

MF Mina ◽

AA Mamun ◽

AK Bledzki

Keyword(s):

Polylactic Acid ◽

Oil Palm ◽

Fiber Length ◽

Empty Fruit Bunch ◽

Green Composites ◽

Acid Effect

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Cellulose Functionalized High Molecular Weight Stereocomplex Polylactic Acid Biocomposite Films with Improved Gas Barrier, Thermomechanical Properties

ACS Sustainable Chemistry & Engineering ◽

10.1021/acssuschemeng.7b01059 ◽

2017 ◽

Vol 5 (8) ◽

pp. 6835-6844 ◽

Cited By ~ 31

Author(s):

Arvind Gupta ◽

Vimal Katiyar

Keyword(s):

Molecular Weight ◽

High Molecular Weight ◽

Polylactic Acid ◽

Thermomechanical Properties ◽

Gas Barrier ◽

Biocomposite Films

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The influence of hot-press temperature and cooling rate on thermal and physicomechanical properties of bamboo particle-polylactic acid composites

Holzforschung ◽

10.1515/hf-2012-0087 ◽

2013 ◽

Vol 67 (3) ◽

pp. 325-331 ◽

Cited By ~ 14

Author(s):

Tung-Lin Wu ◽

Yi-Chi Chien ◽

Tsai-Yung Chen ◽

Jyh-Horng Wu

Keyword(s):

Polylactic Acid ◽

Natural Fiber ◽

Thermomechanical Properties ◽

Hot Press ◽

Press Temperature ◽

Plastic Composite ◽

Large Size ◽

Reinforced Plastic ◽

Superior Mechanical Properties ◽

Bamboo Fibers

Abstract Extrusion and injection moldings are standard processes for fabricating natural fiber-reinforced plastic composites, but both processes are generally not suitable for production of large-size pieces and products with high loadings of lignocelluloses. In this study, a medium-density bamboo plastic composite (BPC) was completely and successfully manufactured from bamboo fibers and polylactic acid (PLA) in the ratio of 1:1 by the flat-platen pressing process. The effects of pressing and cooling parameters on the thermomechanical properties of the BPCPLA have been investigated. The BPCPLA prepared at temperatures >180°C and cooling rates >10°C min-1 exhibited superior mechanical properties and matrix crystallinity. Under these conditions, a stronger interaction between the filler and the polymer matrix occurs and the mobility of the molecular chains at the interface decreases, which leads to a higher stiffness of the composite.

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Plasticizer Enhancement on the Miscibility and Thermomechanical Properties of Polylactic Acid-Chitin-Starch Composites

Polymers ◽

10.3390/polym12010115 ◽

2020 ◽

Vol 12 (1) ◽

pp. 115 ◽

Cited By ~ 6

Author(s):

Indra Surya ◽

N. G. Olaiya ◽

Samsul Rizal ◽

Ikramullah Zein ◽

N. A. Sri Aprilia ◽

...

Keyword(s):

Tensile Strength ◽

Thermogravimetric Analysis ◽

Wear Rate ◽

Water Absorption ◽

Polylactic Acid ◽

Starch Content ◽

Thermomechanical Properties ◽

Morphological Properties ◽

Glass Temperature ◽

Scanning Calorimetry

In previous research, a polylactic chitin starch composite was prepared without the use of a solvent to enhance the miscibility. In this study, a polylactic acid (PLA) chitin starch composite was produced with chloroform as a plasticizer in the ratio 1:10. The blending of chitin and starch with PLA ranges from 2% to 8%. Tensile strength, impact, thermogravimetry analysis-Fourier-transform infrared spectroscopy (TGA)-FTIR, and differential scanning calorimetry (DSC) were used to test the thermomechanical properties. Also, the morphological properties, water absorption, and wear rate of the material was observed. The results showed that the tensile strength, yield strength, and impact strength were improved compared to the pure polylactic acid. Also, the elastic modulus of the samples increased, but were lower compared to that of the pure polylactic acid. The result of the fractured surface morphology showed good miscibility of the blending, which accounted for the good mechanical properties recorded in the study. The thermogravimetric analysis (TGA) and derivative thermogravimetric analysis DTA show a single degradation and peak respectively, which is also shown in the glass temperature measures from the DSC analysis. The water absorption test shows that the water absorption rate increases with starch content and the wear rate recorded sample A (92% P/8% C) as the highest. The high miscibility projected was achieved with no void, with the use of chloroform as a plasticizer.

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