The Physical and Mechanical Properties of Biocomposite Films Composed of Poly(Lactic Acid) with Spent Coffee Grounds

2019 ◽  
Vol 824 ◽  
pp. 87-93
Author(s):  
Nattawut Suaduang ◽  
Sukunya Ross ◽  
Gareth M. Ross ◽  
Supatra Pratumshat ◽  
Sararat Mahasaranon
Keyword(s):  
Lactic Acid ◽  
Physical And Mechanical Properties ◽  
Poly Lactic Acid ◽  
Biodegradable Films ◽  
Spent Coffee Grounds ◽  
Elongation At Break ◽  
Biocomposite Films ◽  
Coffee Grounds ◽  
Twin Screw ◽  
Coffee Oil

The aim of this research was to prepare and characterize biocomposite films from poly(lactic acid) (PLA) with spent coffee grounds (SCG). PLA can be derived from renewable resources. The SCG component consists of cellulose, hemicellulose and coffee oil 10.98%. SCG can simultaneously act as plasticizer and filler in the composites that can enhance the mixing process. The PLA/SCG biocomposite films were processed by a twin-screw extruder and blow film extruder. They were prepared by using various SCG concentrations (0%, 5%, 7.5% and 10% of SCG). The Scanning Electron Microscopy (SEM) results showed that the PLA matrix with SCG was miscible and had the SCG was well good distributed. Elongation at break was increased, when the amount of SCG was increased, with the results of PLA and PLA/SCG 10% being 5.07% and 6.63% respectively, while hardness, brittleness and tensile strength decreased. UV-vis spectrophotometric measurement of PLA/SCG biocomposite films showed a considerable reduction in transmission of all UV wavelengths (UV-A, -B and -C) and visible light with increasing SCG content. Hence, in this research, SCG can be used as filler in PLA films in order to produce biodegradable films and developed as agricultural film products. The PLA/SCG biocomposite films have shown good properties and are environmentally friendly.

Preparation and Characterization of Poly(Lactic Acid) (PLA)/Polyoxymethylene (POM) Blends

2018 ◽  
Vol 917 ◽  
pp. 3-6 ◽  
Author(s):  
Muhammad Haniff ◽  
Mohd Bijarimi ◽  
M.S. Zaidi ◽  
Ahmad Sahrim
Keyword(s):  
Tensile Strength ◽  
Lactic Acid ◽  
Thermal Properties ◽  
Chemical Analysis ◽  
Poly Lactic Acid ◽  
Melt Blending ◽  
Screw Extruder ◽  
Elongation At Break ◽  
Twin Screw

PLA has limited applications due to its inherent brittleness, toughness and low elongation at break. One of the options for improvement is through blending with polyoxymethylene (POM). Melt blending of polylactic acid (PLA) and polyoxymethylene (POM) at 90/10 PLA/POM composition was carried out in a twin-screw extruder. The PLA/POM was loaded with 1 – 5 wt.% of nanoclay (Cloisite C20). The blends were then characterized for mechanical, morphological, chemical and thermal properties. It was found that tensile strength, Young's modulus, and elongation at break improved when the loadings of nanoclay were increased. Chemical analysis by FTIR revealed that PLA/POM blend is immiscible.

scholarly journals Improving the Mechanical Ductility and Toughness of Injection-molded Polylactide Pieces by the Dual Incorporation of Liquor Waste Derived Spent Coffee Grounds and Oligomers of Lactic Acid

2021 ◽  
Author(s):  
Enrique Terroba-Delicado ◽  
Stefano Fiori ◽  
Sergio Torres-Giner ◽  
Jaume Gomez-Caturla ◽  
Nestor Montanes ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Chemical Interaction ◽  
Extrusion Process ◽  
Green Composites ◽  
Green Composite ◽  
Spent Coffee Grounds ◽  
Reinforcing Fillers ◽  
Coffee Grounds ◽  
Coffee Oil ◽  
The Impact

Abstract This work puts the Circular Bioeconomy’s concept into action, originally valorizing residues from the beverage liquor coffee industry into reinforcing fillers for green composites of polylactide (PLA). The as-received spent coffee grains derived from liquor waste were first milled to obtain the so-called spent coffee grounds (SCGs), which were then incorporated at 20 wt.% into PLA by extrusion. With the aim of improving the compatibility between the biopolyester and the lignocellulosic particles, two oligomers of lactic acid (OLAs), namely OLA2 and OLA2mal, being the latter functionalized with maleic anhydride (MAH), were both added during the extrusion process at 10 wt.%. The resultant compounded pellets were finally shaped into pieces by injection molding for characterization. Results showed that, as opposite to most claims published in the literature of PLA composites based on lignocellulosic fillers derived from soluble coffee wastes, the incorporation of liquor waste derived SCGs increased the ductility of the pieces by nearly 280% due to their high coffee oil content. The incorporation of OLA2 and OLA2mal contributed to improve the impact strength of the pieces by approximately 6% and 12.6%, respectively. The higher performance of OLA2mal was ascribed to a reduction of crystallinity in the green composite due to the chemical interaction by the MAH groups. However, the incorporation of SCGs into PLA slighlty reduced the thermal stability and yielded a dark-to-brown color, whereas it also delayed the disintegration rate of the pieces in controlled compost soil. Therefore, the results attained herein open up novel opportunities for the development of green composites of PLA with higher ductility and toughness through the valorization of liquor coffee wastes.

Wood, silver-substituted zeolite and triclosan as biodegradation controllers and antibacterial agents for poly(lactic acid) (PLA) and PLA composites

2015 ◽  
Vol 30 (5) ◽  
pp. 583-598 ◽  
Author(s):  
Chana Prapruddivongs ◽  
Narongrit Sombatsompop
Keyword(s):  
Lactic Acid ◽  
Antimicrobial Agents ◽  
Wood Flour ◽  
Plate Count ◽  
Poly Lactic Acid ◽  
Mechanical And Thermal Properties ◽  
Scanning Calorimetry ◽  
Elongation At Break ◽  
Plate Count Agar ◽  
Twin Screw

Poly(lactic acid) (PLA) and wood flour/PLA composites were prepared and blended with two antimicrobial agents, triclosan and silver-substituted zeolite (Zeomic), using a twin-screw extruder. The mechanical and thermal properties, antimicrobial activity, and biodegradation performance were investigated. The addition of wood and Zeomic was found to increase the Young’s modulus of the composites, whereas the tensile strength, elongation at break, and impact strength dropped. However, the mechanical properties of PLA and wood/PLA loaded with triclosan did not show any definite trends. Differential scanning calorimetry data indicated that the glass transition temperature value of neat PLA was 63°C, whereas those of wood/PLA composites were lower. When wood and Zeomic were incorporated, PLA exhibited double melting peaks. Triclosan (1.0 and 1.5 wt%) demonstrated antibacterial activity against Staphylococcus aureus, as determined by plate count agar technique, whereas Zeomic did not. Biodegradation tests of neat PLA and wood/PLA composites showed that after a 60-day incubation period, the biodegradation rate of wood/PLA was higher than that of PLA. PLA and wood/PLA-containing Zeomic were found to degrade more quickly, suggesting that wood and Zeomic acted as biodegradation promoters. On the other hand, triclosan could be considered a biodegradation retarder since no biodegradation was observed for any triclosan-loaded samples during the initial 20 days of incubation, while neat PLA and wood/PLA composites began to degrade within the first few days.

scholarly journals Rotational Molding of Poly(Lactic Acid)/Polyethylene Blends: Effects of the Mixing Strategy on the Physical and Mechanical Properties

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 217
Author(s):  
Eduardo Ruiz-Silva ◽  
Mirleth Rodríguez-Ortega ◽  
Luis Carlos Rosales-Rivera ◽  
Francisco Javier Moscoso-Sánchez ◽  
Denis Rodrigue ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Oxidative Degradation ◽  
Physical And Mechanical Properties ◽  
Poly Lactic Acid ◽  
Rotational Molding ◽  
Scanning Calorimetry ◽  
Polyethylene Blends ◽  
Twin Screw ◽  
Thermo Oxidative Degradation

In this study, blends of poly(lactic acid) (PLA)/linear medium density polyethylene (LMDPE) at different weight ratios were prepared by rotational molding. Two mixing strategies were used to evaluate the effect of phase dispersion on the physical and mechanical properties: (i) Dry-blending (DB) using a high shear mixer, and (ii) melt-blending (MB) using a twin-screw extruder. Thermal, morphological, and mechanical analyses were performed on the neat polymers and their blends. The thermal analysis was completed by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), and the blends prepared by MB had lower thermal stability than the ones prepared via DB due to some thermo-oxidative degradation through the double thermal process (extrusion and rotomolding). The morphology of the rotomolded parts showed that DB generated larger particle sizes (around 500 µm) compared to MB (around 5 µm) due to the shear and elongational stresses applied during extrusion. The tensile and flexural properties of the rotomolded parts combined the PLA stiffness with the LMDPE toughness independent of the blending technique. Neat PLA presented increments in tensile strength (54%) and flexural strength (111%) for DB compared with MB. A synergistic effect in impact strength was observed in blends with 12 and 25 wt. % of PLA prepared by DB.

Mechanical and Thermal Behaviors of the Acrylic Based Core-Shell Rubber Modified Poly(Lactic Acid)

2011 ◽  
Vol 306-307 ◽  
pp. 340-343 ◽  
Author(s):  
Nawadon Petchwattana ◽  
Sirijutaratana Covavisaruch ◽  
Nukul Euapanthasate
Keyword(s):  
Lactic Acid ◽  
Tensile Modulus ◽  
Degree Of Crystallinity ◽  
Poly Lactic Acid ◽  
Core Shell ◽  
Twin Screw Extrusion ◽  
Elongation At Break ◽  
Screw Extrusion ◽  
Twin Screw ◽  
The Impact

Toughening of poly(lactic acid) (PLA) biopolymer by particles of acrylic based core-shell rubber (CSR) was conducted to observe the influences of the rubber contents on the properties of the modified PLA. A series of PLA specimens modified with the CSR by 0.1-10 wt% was prepared by twin screw extrusion and injection. Diminishing brittleness was reflected in the dramatic increment of both the impact strength by threefolds and the elongation at break by fifteenfolds when CSR was employed by 10 wt%. The toughening was also accompanied with a decrease in the tensile modulus and strength. At low loading, the added CSR by 0.5wt% also assisted crystallization of the PLA by slightly lowering the crystallization temperature, allowing decreased processing time and improving the degree of crystallinity of the generally difficult to crystallize PLA.

scholarly journals Statistical Optimization of Alkali Pretreatment to Improve Sugars Recovery from Spent Coffee Grounds and Utilization in Lactic Acid Fermentation

Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 494 ◽  
Author(s):  
Kang Hyun Lee ◽  
Ye Won Jang ◽  
Jeongho Lee ◽  
Seunghee Kim ◽  
Chulhwan Park ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Enzymatic Hydrolysis ◽  
Lactic Acid Production ◽  
Complex Loading ◽  
Lactic Acid Fermentation ◽  
Optimum Conditions ◽  
Spent Coffee Grounds ◽  
Alkali Pretreatment ◽  
Acid Fermentation ◽  
Coffee Grounds

Biorefinery, which utilizes carbon-neutral biomass as a resource, is attracting attention as a significant alternative in a modern society confronted with climate change. In this study, spent coffee grounds (SCGs) were used as the feedstock for lactic acid fermentation. In order to improve sugar conversion, alkali pretreatment was optimized by a statistical method, namely response surface methodology (RSM). The optimum conditions for the alkali pretreatment of SCGs were determined as follows: 75 °C, 3% potassium hydroxide (KOH) and a time of 2.8 h. The optimum conditions for enzymatic hydrolysis of pretreated SCGs were determined as follows: enzyme complex loading of 30-unit cellulase, 15-unit cellobiase and 50-unit mannanase per g biomass and a reaction time of 96 h. SCG hydrolysates were used as the carbon source for Lactobacillus cultivation, and the conversions of lactic acid by L. brevis ATCC 8287 and L. parabuchneri ATCC 49374 were 40.1% and 55.8%, respectively. Finally, the maximum lactic acid production by L. parabuchneri ATCC 49374 was estimated to be 101.2 g based on 1000 g of SCGs through the optimization of alkali pretreatment and enzymatic hydrolysis.

Mechanical, Thermal, and Morphological Properties of Thermoplastic Starch/Poly(lactic acid/Poly(butylene adipate-co-terephthalate) Blends

2014 ◽  
Vol 970 ◽  
pp. 312-316
Author(s):  
Sujaree Tachaphiboonsap ◽  
Kasama Jarukumjorn
Keyword(s):  
Lactic Acid ◽  
Impact Strength ◽  
Interfacial Adhesion ◽  
Tensile Modulus ◽  
Thermoplastic Starch ◽  
Morphological Properties ◽  
Poly Lactic Acid ◽  
Melt Blending ◽  
Elongation At Break ◽  
Blending Method

Thermoplastic starch (TPS)/poly (lactic acid) (PLA) blend and thermoplastic starch (TPS)/poly (lactic acid) (PLA)/poly (butylene adipate-co-terephthalate) (PBAT) blend were prepared by melt blending method. PLA grafted with maleic anhydride (PLA-g-MA) was used as a compatibilizer to improve the compatibility of the blends. As TPS was incorporated into PLA, elongation at break was increased while tensile strength, tensile modulus, and impact strength were decreased. Tensile properties and impact properties of TPS/PLA blend were improved with adding PLA-g-MA indicating the enhancement of interfacial adhesion between PLA and TPS. With increasing PBAT content, elongation at break and impact strength of TPS/PLA blends were improved. The addition of TPS decreased glass transition temperature (Tg), crystallization temperature (Tc), and melting temperature (Tm) of PLA. Tgand Tcof TPS/PLA blend were decreased by incorporating PLA-g-MA. However, the presence of PBAT reduced Tcof TPS/PLA blend. Thermal properties of TPS/PLA/PBAT blends did not change with increasing PBAT content. SEM micrographs revealed that the compatibilized TPS/PLA blends exhibited finer morphology when compared to the uncompatibilized TPS/PLA blend.

Tensile and water absorption properties of solvent cast biofilms of sugarcane leaves fibre-filled poly(lactic) acid

2018 ◽  
Vol 33 (3) ◽  
pp. 289-304 ◽  
Author(s):  
Kuhananthan Nanthakumar ◽  
Chan Ming Yeng ◽  
Koay Seong Chun
Keyword(s):  
Tensile Strength ◽  
Lactic Acid ◽  
Water Absorption ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Poly Lactic Acid ◽  
Infrared Analysis ◽  
Absorption Properties ◽  
Elongation At Break ◽  
Bleaching Treatment

This research covers the preparation of poly(lactic acid) (PLA)/sugarcane leaves fibre (SLF) biofilms via a solvent-casting method. The results showed that the tensile strength and Young’s modulus of PLA/SLF biofilms increased with the increasing of SLF content. Nevertheless, the elongation at break showed an opposite trend as compared to tensile strength and Young’s modulus of biofilms. Moreover, water absorption properties of PLA/SLF biofilms increased with the increasing of SLF content. In contrast, the tensile strength and Young’s modulus of biofilms were enhanced after bleaching treatment with hydrogen peroxide on SLF, but the elongation at break and water absorption properties of bleached biofilms were reduced due to the improvement of filler–matrix adhesion in biofilms. The tensile and water properties were further discussed using B-factor and Fick’s law, respectively. Furthermore, the functional groups of unbleached and bleached SLF were characterized by Fourier transform infrared analysis.

Sign in / Sign up

Export Citation Format

Share Document