Effects of aging on the thermomechanical properties of poly(lactic acid)

2010 ◽  
Vol 119 (1) ◽  
pp. 472-481 ◽  
Author(s):  
Michael Niaounakis ◽  
Evangelia Kontou ◽  
Menelaos Xanthis
Keyword(s):  
Lactic Acid ◽  
Thermomechanical Properties ◽  
Poly Lactic Acid ◽  
Effects Of Aging

scholarly journals Feasibility of Reprocessing Natural Fiber Filled Poly(lactic acid) Composites: An In-Depth Investigation

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Sujal Bhattacharjee ◽  
Dilpreet S. Bajwa
Keyword(s):  
Lactic Acid ◽  
Natural Fiber ◽  
Environmental Concern ◽  
Wood Flour ◽  
Gel Permeation Chromatography ◽  
Thermomechanical Properties ◽  
Poly Lactic Acid ◽  
Filler Concentration ◽  
Scanning Calorimetry ◽  
Abrupt Decrease

Poly(lactic acid) (PLA) based composites are biodegradable; their disposal after single use may be needless and uneconomical. Prodigal disposal of these composites could also create an environmental concern and additional demand for biobased feedstock. Under these circumstances, recycling could be an effective solution, since it will widen the composite service life and prevent the excessive use of natural resources. This research investigates an in-depth impact of recycling on the mechanical and thermomechanical properties of oak wood flour based PLA composites. Two composite formulations (30 and 50 wt% filler), each with 3 wt% coupling agent (PLA-g-MA), were produced and reprocessed six times by extrusion followed by injection molding. Measurements of fiber length and molecular weight of polymer were, respectively, carried out by gel permeation chromatography (GPC). Scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FTIR) tools were used to study morphological and molecular alterations. With consecutive recycling, PLA composites showed a gradual decrease in strength and stiffness properties and an increase in strain properties. The 50% and 30% filler concentration of fibers in the composite showed an abrupt decrease in strength properties after six and two reprocessing cycles, respectively.

Thermomechanical properties of poly(lactic acid) films reinforced with hydroxyapatite and regenerated cellulose microfibers

2014 ◽  
Vol 131 (20) ◽  
pp. n/a-n/a
Author(s):  
Arman Mahboubi Soufiani ◽  
Masoud Salehi ◽  
Mikael Skrifvars ◽  
Maria Persson ◽  
Sung-Woo Cho
Keyword(s):  
Lactic Acid ◽  
Thermomechanical Properties ◽  
Poly Lactic Acid ◽  
Regenerated Cellulose ◽  
Cellulose Microfibers

scholarly journals Effects of aging on the adhesive properties of poly(lactic acid) by atmospheric air plasma treatment

2015 ◽  
Vol 133 (11) ◽  
pp. n/a-n/a ◽  
Author(s):  
A. Jordá-Vilaplana ◽  
L. Sánchez-Nácher ◽  
D. García-Sanoguera ◽  
A. Carbonell ◽  
J. M. Ferri
Keyword(s):  
Lactic Acid ◽  
Plasma Treatment ◽  
Poly Lactic Acid ◽  
Air Plasma ◽  
Adhesive Properties ◽  
Atmospheric Air ◽  
Effects Of Aging ◽  
Air Plasma Treatment

scholarly journals Water-Induced Breaking of Interfacial Cohesiveness in a Poly(lactic acid)/Miscanthus Fibers Biocomposite

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2285
Author(s):  
Nicolas Delpouve ◽  
Hajar Faraj ◽  
Clément Demarest ◽  
Eric Dontzoff ◽  
Marie-Rose Garda ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Hydrolytic Degradation ◽  
Thermomechanical Properties ◽  
Degree Of Crystallinity ◽  
Poly Lactic Acid ◽  
Incomplete Filling ◽  
The Matrix ◽  
High Elongation ◽  
The Impact

The impact of the immersion in water on the morphology and the thermomechanical properties of a biocomposite made of a matrix of poly (lactic acid) (PLA) modified with an ethylene acrylate toughening agent, and reinforced with miscanthus fibers, has been investigated. Whereas no evidence of hydrolytic degradation has been found, the mechanical properties of the biocomposite have been weakened by the immersion. Scanning electron microscopy (SEM) pictures reveal that the water-induced degradation is mainly driven by the cracking of the fiber/matrix interface, suggesting that the cohesiveness is a preponderant factor to consider for the control of the biocomposite decomposition in aqueous environments. Interestingly, it is observed that the loss of mechanical properties is aggravated when the stereoregularity of PLA is the highest, and when increasing the degree of crystallinity. To investigate the influence of the annealing on the matrix behavior, crystallization at various temperatures has been performed on tensile bars of PLA made by additive manufacturing with an incomplete filling to enhance the contact area between water and polymer. While a clear fragilization occurs in the material crystallized at high temperature, PLA crystallized at low temperature better maintains its properties and even shows high elongation at break likely due to the low size of the spherulites in these annealing conditions. These results show that the tailoring of the mesoscale organization in biopolymers and biocomposites can help control their property evolution and possibly their degradation in water.

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