Poly(lactic acid)/polystyrene bioblends characterized by thermogravimetric analysis, differential scanning calorimetry, and photoacoustic infrared spectroscopy

2007 ◽  
Vol 106 (3) ◽  
pp. 1689-1696 ◽  
Author(s):  
Abdellatif Mohamed ◽  
Sherald H. Gordon ◽  
Girma Biresaw
Keyword(s):  
Differential Scanning Calorimetry ◽  
Lactic Acid ◽  
Infrared Spectroscopy ◽  
Thermogravimetric Analysis ◽  
Poly Lactic Acid ◽  
Scanning Calorimetry

Preparation and characterization of poly(lactic acid) with adipate ester added as a plasticizer

2018 ◽  
Vol 26 (8-9) ◽  
pp. 446-453 ◽  
Author(s):  
Chi-Hui Tsou ◽  
Chen Gao ◽  
Manuel De Guzman ◽  
Dung-Yi Wu ◽  
Wei-Song Hung ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Fourier Transform ◽  
Lactic Acid ◽  
Infrared Spectroscopy ◽  
Poly Lactic Acid ◽  
Biodegradable Materials ◽  
Scanning Calorimetry ◽  
Elongation At Break ◽  
Plasticizer Migration

Poly(lactic acid) (PLA) was thermally blended with adipate ester (AE) to enhance the toughness of PLA. All specimens which were biodegradable materials were prepared using a plasticorder. Differential scanning calorimetry and Fourier-transform infrared spectroscopy indicated that the PLA structure was looser because of the presence of the AE additive. The elongation at break and biodegradable property increased substantially with increasing amounts of AE. The results reveal that excessive amounts of plasticizer would cause the exudation of AE from the PLA/AE composites, which was ascribed to the plasticizer migration phenomenon.

scholarly journals Amine Responsive Poly(lactic acid) (PLA) and Succinic Anhydride (SAh) Graft-Polymer: Synthesis and Characterization

Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1466 ◽  
Author(s):  
Adrián Lopera-Valle ◽  
Anastasia Elias
Keyword(s):  
Differential Scanning Calorimetry ◽  
Lactic Acid ◽  
Thermal Properties ◽  
Infrared Spectroscopy ◽  
Photoelectron Spectroscopy ◽  
Succinic Anhydride ◽  
Poly Lactic Acid ◽  
Scanning Calorimetry ◽  
Amidation Reaction ◽  
Graft Polymers

Amines are known to react with succinic anhydride (SAh), which in reactions near room temperature, undergoes a ring opening amidation reaction to form succinamic acid (succinic acid-amine). In this work, we propose to form an amine-responsive polymer by grafting SAh to a poly(lactic acid) (PLA) backbone, such that the PLA can provide chemical and mechanical stability for the functional SAh during the amidation reaction. Grafting is performed in a toluene solution at mass content from 10 wt% to 75 wt% maleic anhydride (MAh) (with respect to PLA and initiator), and films are then cast. The molecular weight and thermal properties of the various grafted polymers are measured by gel permeation chromatography and differential scanning calorimetry, and the chemical modification of these materials is examined using infrared spectroscopy. The efficiency of the grafting reaction is estimated with thermogravimetric analysis. The degree of grafting is determined to range from 5% to 42%; this high degree of grafting is desirable to engineer an amine-responsive material. The response of the graft-polymers to amines is characterized using X-ray photoelectron spectroscopy, infrared spectroscopy, and differential scanning calorimetry. Changes in the chemical and thermal properties of the graft-polymers are observed after exposure to the vapors from a 400 ppm methylamine solution. In contrast to these changes, control samples of neat PLA do not undergo comparable changes in properties upon exposure to methylamine vapor. In addition, the PLA-g-SAh do not undergo changes in structure when exposed to vapors from deionized water without amines. This work presents potential opportunities for the development of real-time amine sensors.

RETRACTED: Fabrication of Poly(Lactic Acid) Nanofibers by Cotton Candy Method

2017 ◽  
Vol 728 ◽  
pp. 193-198
Author(s):  
Rutchaneekorn Wongpajan ◽  
Supaphorn Thumsorn ◽  
Hiroyuki Inoya ◽  
Masayuki Okoshi ◽  
Hiroyuki Hamada
Keyword(s):  
Differential Scanning Calorimetry ◽  
Lactic Acid ◽  
Thermal Properties ◽  
Electron Microscope ◽  
Air Pressure ◽  
Poly Lactic Acid ◽  
Scanning Calorimetry ◽  
Cotton Candy ◽  
Nozzle Temperature ◽  
Scanning Electron

The poly (lactic acid) (PLA) fiber of biodegradable polymer was fabricated by cotton candy method with small nozzle. The air pressure was varied from 0.2-0.5 MPa with nozzle temperature of 210-260°C. The morphology of fiber was determined by scanning electron microscope (SEM). Thermal properties were examined using differential scanning calorimetry (DSC). SEM results suggested that diameters the PLA fiber at temperature 250°C and air pressure of 0.2 MPa were smaller than the fiber at low and high temperature. The sizes of the fibers were lower than 1 μm and the fibers were irregular size. Crystallinity significantly decreased when increasing barrel temperatures while it slightly changed when varied air pressure. The productivity of PLA fibers was around 30-180 g/h depended on controlled the nozzle temperature and the air pressure.

Multiple melting behavior of poly(lactic acid)-hemp-silica composites using modulated-temperature differential scanning calorimetry

2014 ◽  
Vol 34 (9) ◽  
pp. 895-903 ◽  
Author(s):  
Izan R. Mustapa ◽  
Robert A. Shanks ◽  
Ing Kong
Keyword(s):  
Differential Scanning Calorimetry ◽  
Heat Capacity ◽  
Lactic Acid ◽  
Melting Behavior ◽  
Woven Fabric ◽  
Melting Peak ◽  
Poly Lactic Acid ◽  
Scanning Calorimetry ◽  
Modulated Temperature ◽  
Multiple Melting

Abstract Poly(lactic acid) (PLA)-hemp-nanosilica (PHS) composites were prepared by impregnation of hemp woven fabric with PLA solution. Nanosilica was dispersed in the PLA solution to introduce a matrix reinforcing nanophase within the composite. The melting behavior of PLA composites was obtained by using differential scanning calorimetry (DSC) and modulated-temperature DSC (mT-DSC). Multiple melting which appeared in the non-isothermal heating curve showed that the temperature of a low melting peak increased when using a slower scanning rate. The incorporation of nanosilica in PLA composites affected the melting temperature (Tm) and sufficiently formed nucleation sites that promoted the growth of PLA crystals. Composites analyzed by a temperature-modulated program showed a broad exothermic peak before the melting peak in the non-reversing heat capacity and endothermic melting in the reversing heat capacity curve. This behavior was explained by a process of partial melting, recrystallization and remelting (mrr). The mT-DSC resolved that hemp fiber induced recrystallization and nanosilica acted as an effective nucleating agent, which promoted small and imperfect crystals that changed successively into more stable crystals through a melt-recrystallization process.

Crystallization Behavior of Poly(lactic acid) Nucleated by a Hydrazide Compound

2013 ◽  
Vol 710 ◽  
pp. 85-88 ◽  
Author(s):  
Cheng Lang Li ◽  
Qiang Dou
Keyword(s):  
Differential Scanning Calorimetry ◽  
Lactic Acid ◽  
Crystallization Behavior ◽  
Polarized Light ◽  
Nucleating Agent ◽  
Poly Lactic Acid ◽  
Melt Blending ◽  
Scanning Calorimetry ◽  
Internal Mixer ◽  
Melting And Crystallization

A hydrazide compound (N-4) was used as a nucleating agent to induce the crystallization of poly (lactic acid) (PLA). PLA/N-4 samples were prepared by melt blending in an internal mixer. The melting and crystallization behavior and spherulitic morphology of the samples doped with different contents of N-4 were investigated by means of differential scanning calorimetry (DSC) and polarized light microscopy (PLM). It is found that the crystallization temperature and crystallinity increased but the spherulitic size of PLA decreased for the nucleated samples. It is indicated that N-4 is an effective nucleating agent for PLA.

scholarly journals Extraction of Lignin from Empty Fruit Bunch Fiber via Microwave-Assisted Acid Hydrotrope Solvent

2021 ◽  
Vol 1 (2) ◽  
pp. 26-33
Author(s):  
Rasidi Roslan ◽  
Muhammad Nor Arifin Yaakob ◽  
Ms Fathihah
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Differential Scanning Calorimetry ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Reaction Time ◽  
Thermogravimetric Analysis ◽  
Empty Fruit Bunch ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Microwave Assisted

Lignin is a sub-product from lignocellulose apart from cellulose and hemicellulose that produced from empty fruit bunch fiber (EFB). Lignin has low solubility and reactivity due to its bulky macromolecule structre. Being one of the wastes that being generated in massive amount, many alternatives has been taken to transform lignin into valuable products. To do so, many reactions are needed for the lignin to go through. In this study, lignin will be extracted from empty fruit bunch (EFB) with the aid of acid hydrotrope concentration of 30 % and microwave assisted with various extraction heating time and temperature. Characterization of lignin is done using Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric analysis (TGA), Differential Scanning Calorimetry (DSC) and Nuclear magnetic resonance (NMR) while Scanning Electron Microscopy (SEM) and X-ray Powder Diffraction (XRD) used to characterize residues. The highest percentage of lignin yield and its purity obtained are 19.47 % and 96.63 % with the reaction time and temperature of the microwave is 30 minutes and 90 °C. From Fourier Transform Infrared Spectroscopy (FTIR), a wide band at 3430.09 cm-1 and 3413.45 cm-1 are observed due to O-H stretching vibration. As for peak at 1123.17 cm-1 and 1051.26 cm-1, it correspond to syringyl and guaicyl unit in both lignin and raw EFB. As for Thermogravimetric analysis (TGA), it shows that lignin decomposes slowly compared to raw EFB due to the aromatic structure of lignin that is very stable, therefore leading to difficulty of decomposing while from Differential Scanning Calorimetry (DSC), after removing cellulose and hemicellulose, glass transition temperature (Tg) obtained from lignin DSC spectroscopy is 193.05 °C at heat flow of 1.15 mW/mg. Next, from Nuclear magnetic resonance (NMR) spectroscopy, the signals observed around 6.5 – 8.0 ppm indicate aromatic H in syringyl and guaiacyl unit only at lignin spectra while at 3.3 – 4.0 ppm, raw EFB has an intense peak compared to lignin which attribute to methoxyl group. When the residue of the lignin as well as the raw EFB powder is characterized using X-ray Powder Diffraction (XRD), the crystallinity index of the lignin with reaction time and temperature of the microwave 30 minutes and 90 °C is the highest, 69.28 %. As a conclusion, an admissible percent of lignin yield and purity is able to be obtained with addition of acid hydrotrope depending on the variables. From the spectroscopies characterization, it is proved that lignin characteristics and properties are compatible for the production of new and value added products.

scholarly journals SYNTHESIS OF NiO/ZnO NANOCOMPOSITES IN ETHYLENE GLYCOL

2020 ◽  
Author(s):  
Bakhtawar Sajjad ◽  
Umer Ali ◽  
Auswa Nadeem ◽  
Lubna Noor ◽  
Muhammad Akhyar Farrukh
Keyword(s):  
Differential Scanning Calorimetry ◽  
Particle Size ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Thermogravimetric Analysis ◽  
Ethylene Glycol ◽  
Sol Gel ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Scanning Calorimetry

Ethylene glycol is solvent used in sol-gel method to synthesize NiO/ZnO nanocomposites. ZnCl2 along with NiCl2.6H2O were used as precursors during synthetization of NiO/ZnO nanocomposites. We used various techniques such as Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), Fourier Transform Infrared Spectroscopy (FTIR) and particle size analysis for synthesis of the nanocomposites which confirm that these nanocomposites act as catalyst.

Plasticizing effects of citrate esters on properties of poly(lactic acid)

2016 ◽  
Vol 36 (4) ◽  
pp. 371-380 ◽  
Author(s):  
Mounira Maiza ◽  
Mohamed Tahar Benaniba ◽  
Valérie Massardier-Nageotte
Keyword(s):  
Differential Scanning Calorimetry ◽  
Lactic Acid ◽  
Mechanical Analysis ◽  
Poly Lactic Acid ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Intermolecular Hydrogen Bonds ◽  
X Ray ◽  
Triethyl Citrate ◽  
Acetyl Tributyl Citrate

Abstract Triethyl citrate (TEC) and acetyl tributyl citrate (ATBC) were used as plasticizer for poly(lactic acid) (PLA). The treated and plasticized PLA at various concentrations were analyzed by differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and opacity. DSC was used to evaluate the crystallinity and thermal property of all the samples. It was found that the glass transition temperature (Tg) and the melting temperature (Tm) decreased as the amount of citrate esters increased. Additionally, the presence of TEC or ATBC tended to increase the crystallinity of PLA. This result was supported by XRD. DMA of plasticized PLA indicates that a decrease in Tg is obtained with increasing plasticizer content. FTIR spectra indicate that there are some molecular interactions by intermolecular hydrogen bonds between PLA and citrate esters. The effect of the concentration of plasticizer on the opacity of the films was negligible.

Encapsulation of Bioactive Compounds (Monocaprin and Monolaurin) into Polymeric Nanoparticles

2018 ◽  
Vol 916 ◽  
pp. 147-152 ◽  
Author(s):  
Paramaporn Chiewpattanakul Kaewmanee ◽  
Benjamas Wongsatayanon ◽  
Alain Durand
Keyword(s):  
Differential Scanning Calorimetry ◽  
Lactic Acid ◽  
Bioactive Compounds ◽  
Polymeric Nanoparticles ◽  
Poly Lactic Acid ◽  
Scanning Calorimetry ◽  
Nanoparticle Suspension

The dextran-covered poly (lactic acid) (PLA) polymeric nanoparticles were prepared by a nanoprecipitation process for the encapsulation of monocaprin (MC) or monolaurin (ML). The concentration of PLA/MC or ML was varied to evaluate the best condition for preparation. The miscibility of various PLA/MC or ML blends was studied using differential scanning calorimetry. The result showed that at concentrations of 50/50 wt/wt, the PLA/ML blend was partly miscible and the nanoparticle suspension produced large amounts of macroscopic aggregates after nanoprecipitation. Conversely, the miscibility of PLA/MC blends progressively increased with increasing amounts of PLA. Therefore, the best concentration to encapsulate the MC was the PLA/MC 90/10 (wt/wt), according to the miscibility results.

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