Preparation and characterization of EVA/PLA/sugarcane bagasse composites for water purification

2016 ◽  
Vol 51 (9) ◽  
pp. 1169-1186 ◽  
Author(s):  
TA Makhetha ◽  
K Mpitso ◽  
AS Luyt
Keyword(s):  
Lactic Acid ◽  
Vinyl Acetate ◽  
Sugarcane Bagasse ◽  
Ethylene Vinyl Acetate ◽  
Poly Lactic Acid ◽  
Melt Mixing ◽  
Lower Viscosity ◽  
Monolayer Adsorption ◽  
Sample Water ◽  
The Impact

Poly(lactic acid)/ethylene vinyl acetate blends and poly(lactic acid)/ethylene vinyl acetate/sugarcane bagasse composites were prepared by melt mixing. The lower viscosity of poly(lactic acid), the lower interfacial tension between poly(lactic acid) and sugarcane bagasse, and the wetting coefficient of poly(lactic acid)/sugarcane bagasse being larger than one, all suggested that sugarcane bagasse would preferably be in contact with poly(lactic acid). A fairly good dispersion of sugarcane bagasse was observed in the composites. Exposed fibre ends were observed in the composite micrographs, which were believed to add to the efficiency of metal adsorption. The impact properties depended more on the poly(lactic acid):ethylene vinyl acetate ratio than on the presence of sugarcane bagasse. The poly(lactic acid)/ethylene vinyl acetate blends showed two melting peaks at approximately the same temperatures as those of the neat polymers, which confirms the complete immiscibility of poly(lactic acid) and ethylene vinyl acetate at all the investigated compositions. Sugarcane bagasse-related weight loss occurred at higher temperatures for sugarcane bagasse in the composites, which could have been the result of the sugarcane bagasse being protected by the polymers, or a delay in the diffusion of the sugarcane bagasse decomposition products out of the sample. Water absorption increased with an increase in sugarcane bagasse loading in the composites. More lead was adsorbed than one would expect if the partial coverage of the fibre by the polymer is taken into account, and therefore it may be assumed that some of the lead was trapped inside the cavities in the composites and that the polymers may also have played a role in the metal complexation process, since both polymers have functional groups that could interact with the lead ions. The metal impurities underwent monolayer adsorption.

Effects of Poly(Methyl Methacrylate)-Encapsulated Nanosilica on Mechanical Properties of Poly(Lactic Acid)/Ethylene Vinyl Acetate Nanocomposites

2018 ◽  
Vol 773 ◽  
pp. 51-55
Author(s):  
Jasmine Pongkasem ◽  
Saowaroj Chuayjuljit ◽  
Phasawat Chaiwutthinan ◽  
Amnouy Larpkasemsuk ◽  
Anyaporn Boonmahitthisud
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Impact Strength ◽  
Methyl Methacrylate ◽  
Tensile Properties ◽  
Vinyl Acetate ◽  
Ethylene Vinyl Acetate ◽  
Poly Lactic Acid ◽  
Poly Methyl Methacrylate ◽  
The Impact

In this study, poly(lactic acid) (PLA) was melt mixed with three weight percentages (10–30wt%) of ethylene vinyl acetate copolymer (EVA) in an internal mixer, followed by a compression molding. According to a better combination of mechanical properties, the 90/10 (w/w) PLA/EVA was selected for preparing hybrid nanocomposites with three loadings (1, 3 and 5 parts per hundred of resin , phr) of poly(methyl methacrylate)-encapsulated nanosilica (PMMA-nSiO2). The nanolatex of PMMA-nSiO2 was synthesized via in situ differential microemulsion polymerization. The obtained PMMA-nSiO2 showed a core-shell morphology with nSiO2 as a core and PMMA as a shell, having an average diameter of 43.4nm. The influences of the EVA and PMMA-nSiO2 on the impact strength and the tensile properties of the PLA/EVA nanocomposites were studied and compared. It is found that the impact strength and the tensile properties of the 90/10 (w/w) PLA/EVA were improved with the appropriate amounts of the EVA and PMMA-nSiO2.

scholarly journals Impact of the Graphite Fillers on the Thermal Processing of Graphite/Poly(lactic acid) Composites

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5346
Author(s):  
Daniel Kaczor ◽  
Kacper Fiedurek ◽  
Krzysztof Bajer ◽  
Aneta Raszkowska-Kaczor ◽  
Grzegorz Domek ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Polymer Matrix ◽  
Thermal Processing ◽  
Poly Lactic Acid ◽  
Expandable Graphite ◽  
Slight Reduction ◽  
Melt Mixing ◽  
Neat Polymer ◽  
Industrial Grade ◽  
The Impact

To assess the impact of graphite fillers on the thermal processing of graphite/poly(lactic acid) (PLA) composites, a series of the composite samples with different graphite of industrial grade as fillers was prepared by melt mixing. The average size of the graphite grains ranged between 100 µm and 6 µm. For comparative purposes, one of the carbon fillers was expandable graphite. Composites were examined by SEM, FTIR, and Raman spectroscopy. As revealed by thermogravimetric (TG) analyses, graphite filler slightly lowered the temperature of thermal decomposition of the PLA matrix. Differential scanning calorimetry (DSC) tests showed that the room temperature crystallinity of the polymer matrix is strongly affected by the graphite filler. The crystallinity of the composites determined from the second heating cycle reached values close to 50%, while these values are close to zero for the neat polymer. The addition of graphite to PLA caused a slight reduction in the oxidation induction time (OIT). The melt flow rate (MFR) of the graphite/PLA composites was lower than the original PLA due to an increase in flow resistance associated with the high crystallinity of the polymer matrix. Expandable graphite did not cause changes in the structure of the polymer matrix during thermal treatment. The crystallinity of the composite with this filler did not increase after first heating and was close to the neat PLA MFR value, which was extremely high due to the low crystallinity of the PLA matrix and delamination of the filler at elevated temperature.

Biocomposites of Poly(Lactic Acid) and Cellulose Nanofibers from Cassava Pulp

2017 ◽  
Vol 753 ◽  
pp. 13-17
Author(s):  
Chi Nguyen Thanh ◽  
Ruksakulpiwat Chaiwat ◽  
Ruksakulpiwat Yupaporn
Keyword(s):  
Electron Microscopy ◽  
Lactic Acid ◽  
Impact Strength ◽  
Epoxy Group ◽  
Cellulose Nanofibers ◽  
Poly Lactic Acid ◽  
Melt Mixing ◽  
Hydrolysis Method ◽  
Cassava Pulp ◽  
The Impact

Cellulose nanofibers (CNFs) were used as biobased fillers to prepare poly(lactic acid) (PLA)-based biocomposites. Cellulose nanofibers were extracted from cassava pulp (CP) by acid hydrolysis method. Before submitted to acid treatment, CP was pre-treated by alkali and bleaching treatments. The biocomposites were prepared by melt mixing, followed by hot melt pressing. In order to improve the compatibility of CNFs with PLA matrix, glycidyl methacrylate (GMA) grafted poly (lactic acid) (PLA-g-GMA) was used as a compatibilizer. PLA-g-GMA was prepared by grafting of GMA onto PLA chain via melt mixing using an internal mixer. Transmission electron microscopy (TEM) micrograph shows that most nanofibers with the diameter in the range of 10-30 nm and immeasurable length were obtained. The appearance of two new peaks at 49.07 and 44.71 ppm in the carbon-13 nuclear magnetic resonance (13C-NMR) spectrum of PLA-g-GMA, which represent the carbons of the epoxy group of GMA, confirms that GMA was successfully grafted onto PLA chain. The morphology of biocomposites, characterized by scanning electron microscopy (SEM), reveals that without using PLA-g-GMA, the poor dispersion of CNFs in PLA matrix was observed. In contrast to that, with using PLA-g-GMA, the dispersion of CNFs in PLA matrix was improved. Moreover, the impact strength results show that by incorporating 1.0 wt% CNFs into PLA matrix and using PLA-g-GMA as a compatibilizer, the impact strength of biocomposites was slightly enhanced compared to that of pure PLA.

Super toughened renewable poly(lactic acid) based ternary blends system: effect of degree of hydrolysis of ethylene vinyl acetate on impact and thermal properties

RSC Advances ◽  
2016 ◽  
Vol 6 (76) ◽  
pp. 72681-72691 ◽  
Author(s):  
V. H. Sangeetha ◽  
Ravi babu Valapa ◽  
S. K. Nayak ◽  
T. O. Varghese
Keyword(s):  
Lactic Acid ◽  
Thermal Properties ◽  
Vinyl Acetate ◽  
Ethylene Vinyl Acetate ◽  
Poly Lactic Acid ◽  
Ternary Blend ◽  
Degree Of Hydrolysis ◽  
Ternary Blends ◽  
System Effect ◽  
Hydrolysis Of

Effect of hydrolysed EVA on PLA ternary blend systems.

Comparison of Morphology and Mechanical Properties of Polyoxymethylene/Cellulose and Poly(Lactic Acid)/Cellulose Composites

2018 ◽  
Vol 916 ◽  
pp. 19-23 ◽  
Author(s):  
Sirirat Wacharawichanant ◽  
Nisarat Wimonsupakit ◽  
Sasithorn Kuhaudomlap
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Poly Lactic Acid ◽  
Melt Mixing ◽  
Cellulose Composites ◽  
Internal Mixer ◽  
The Impact ◽  
Morphology And Mechanical Properties

The objective of this study is to fabricate the polyoxymethylene (POM)/microcrystalline cellulose (MCC) and poly(lactic acid) (PLA)/MCC composites, and to compare the effect of MCC on the morphology and mechanical properties of POM and PLA. The polymer composites were prepared by melt mixing in an internal mixer and molded by compression molding. The MCC concentrations were 1, 3, 5, 7, 10, 15 and 10% by weight. From scanning electron microscopy study observes the fracture surface of POM and PLA composites is much rough and the roughness increases with increasing MCC content. This observation indicates MCC induces the ductile fracture characteristic of POM and PLA. The addition of MCC can improve the impact strength of PLA composite and improve Young’s modulus of both POM and PLA composites. While the tensile strength and strain at break decrease after adding MCC. In summary, MCC can enhance the morphology and mechanical properties of PLA composites is better than POM composites.

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