scholarly journals A Simple-to-Implement Simulator for the Reactive Extrusion of Poly(Lactic Acid) in a Corotating Uniform Twin-Screw Extruder

2015 ◽  
Vol 2015 ◽  
pp. 1-13
Author(s):  
René O. Vargas ◽  
J. Esteban López-Aguilar ◽  
Lorenzo A. Martínez-Suástegui ◽  
Francisco López-Serrano
Keyword(s):  
Lactic Acid ◽  
Reactive Extrusion ◽  
Poly Lactic Acid ◽  
Twin Screw Extruder ◽  
Reactive Processing ◽  
Screw Extruder ◽  
Radical Ring ◽  
Practical Applications ◽  
Numerical Predictions ◽  
Twin Screw

The present paper deals with the poly(lactic acid) (PLA) reactive processing simulation in a uniform corotating twin-screw extruder that can be readily turned into practical applications in pilot and industrial equipment. The simulator provides a cause-effect guide that can be useful for starting an experimental setup in a reactive screw extruder for a biopolymer in a growing industry. The proposed model considers a free radical ring-opening mechanism involving the main characteristic flows inside the extruder and the non-Newtonian behavior of PLA. The characteristic behavior relating reaction rate, average molecular weights, and polydispersity against chamber number are described by S-shaped and monotonically decreasing curves, for the equipment. Numerical predictions show that this simple and easy to implement model accurately reproduces previously reported data and that the impurity concentration exhibits a marked effect over all the variables, except conversion.

scholarly journals Properties of Poly(Lactic Acid) Filled with Hydrophobic Cellulose/SiO2 Composites

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Kittithorn Lertphirun ◽  
Kawee Srikulkit
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Hydrolytic Degradation ◽  
Poly Lactic Acid ◽  
Twin Screw Extruder ◽  
Screw Extruder ◽  
Twin Screw ◽  
Hydrolysis Of Cellulose ◽  
One Step ◽  
Hydrolysis Of

Hydrophobic cellulose/SiO2 composites were prepared. Resultant hydrophobic cellulose/SiO2 composites were melt mixed with PLA using a twin-screw extruder to obtain 10 wt% masterbatch. Again, 10 wt% masterbatch was melt mixed with virgin PLA, resulting in PLA containing hydrophobic cellulose/SiO2 at various contents (1 wt%, 3 wt%, and 5 wt%) using a twin-screw extruder (barrel zone temperature: 150/160/170/180/190°C (die zone)). Injection-molded samples were prepared for mechanical properties evaluation. Results showed that poor mechanical properties found at low percent loadings were associated with a significant depolymerization of masterbatch composition due to twice thermal treatments. Note that 10 wt% masterbatch was subjected to injection molding straight away in a one-step process. Results showed that 10 wt% hydrophobic cellulose/SiO2/PLA composites exhibited mechanical properties equivalent to neat PLA. Importantly, the addition of hydrophobic cellulose/SiO2 at high percent loading could favor landfill degradation of PLA via water absorption ability of cellulose. It was expected that enzymatic hydrolysis of cellulose resulted in the formation of lactic acid and silicic acid which consequently catalyzed the hydrolytic degradation (acid hydrolysis) of PLA. The hydrolytic degradation produced carboxylic acid end group which further accelerated the degradation rate.

scholarly journals Poly(Lactic Acid) (PLA)/Acrylonitrile Butadiene Styrene (ABS) with Graphene Nanoplatelet (GNP) Nanocomposites

2020 ◽  
Vol 20 (2) ◽  
pp. 276 ◽  
Author(s):  
Mohd Bijarimi ◽  
Noor Shahadah ◽  
Azizan Ramli ◽  
Said Nurdin ◽  
Waleed Alhadadi ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Lactic Acid ◽  
Acrylonitrile Butadiene Styrene ◽  
Poly Lactic Acid ◽  
Twin Screw Extruder ◽  
Melt Blending ◽  
Screw Extruder ◽  
Graphene Nanoplatelet ◽  
Twin Screw ◽  
Butadiene Styrene

A melt blending of poly(lactic acid) (PLA)/acrylonitrile-butadiene-styrene (ABS) with 30:70 PLA:ABS was prepared by a twin screw extruder with a die of 25 mm width and 0.5 mm thickness with various loadings of graphene (0–1.0 wt.%). The PLA/ABS blends were evaluated by mechanical, morphology, thermal and interaction of the components of the blend. Results show the incorporation of graphene nanoplatelet (GNP) improved the tensile and modulus properties. Nevertheless, it was observed that at higher GNP loadings i.e. 0.6–1.0 wt.%, both tensile and modulus properties showed a decreasing trend. It was also found that the thermal stability for the blend slightly improved when graphene presence in the blend.

Biodegradable binary blend of poly(lactic acid) / polypropylene via twin-screw extruder : Preparation and characterization

2021 ◽  
Author(s):  
Rudzaimi M. ◽  
Mohd Bijarimi ◽  
Farah Hafidzah ◽  
Waleed Alhadadi ◽  
MSZ Desa ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Poly Lactic Acid ◽  
Twin Screw Extruder ◽  
Screw Extruder ◽  
Binary Blend ◽  
Twin Screw

scholarly journals Investigation of the Thermal and Hydrolytic Degradation of Polylactide during Autoclave Foaming

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2624
Author(s):  
Julia Dreier ◽  
Christian Brütting ◽  
Holger Ruckdäschel ◽  
Volker Altstädt ◽  
Christian Bonten
Keyword(s):  
Thermal Degradation ◽  
Hydrolytic Degradation ◽  
Reactive Extrusion ◽  
Foaming Properties ◽  
Twin Screw Extruder ◽  
Degradation Behavior ◽  
Screw Extruder ◽  
Melt Strength ◽  
Twin Screw ◽  
Good Potential

Polylactide (PLA) is one of the most important bioplastics worldwide and thus represents a good potential substitute for bead foams made of the fossil-based Polystyrene (PS). However, foaming of PLA comes with a few challenges. One disadvantage of commercially available PLA is its low melt strength and elongation properties, which play an important role in foaming. As a polyester, PLA is also very sensitive to thermal and hydrolytic degradation. Possibilities to overcome these disadvantages can be found in literature, but improving the properties for foaming of PLA as well as the degradation behavior during foaming have not been investigated yet. In this study, reactive extrusion on a twin-screw extruder is used to modify PLA in order to increase the melt strength and to protect it against thermal degradation and hydrolysis. PLA foams are produced in an already known process from the literature and the influence of the modifiers on the properties is estimated. The results show that it is possible to enhance the foaming properties of PLA and to protect it against hydrolysis at the same time.

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