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.

Preparation of Poly(Lactic Acid)/Bentonite Clay Bio-Nanocomposite

2014 ◽  
Vol 775-776 ◽  
pp. 233-237 ◽  
Author(s):  
Dayanne Diniz Souza Morais ◽  
Renata Barbosa ◽  
Keila Machado Medeiros ◽  
Edcleide Maria Araújo ◽  
Tomás Jefférson Alves de Mélo
Keyword(s):  
Differential Scanning Calorimetry ◽  
Lactic Acid ◽  
Thermal Properties ◽  
Pharmaceutical Industry ◽  
Bentonite Clay ◽  
Poly Lactic Acid ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Double Peaks

Recent advances in biodegradable polymers have attracted a great interest not only in traditional areas such as biomedical and pharmaceutical industry, but also in packaging applications, articles and injected membranes. The aim of this work was to produce bio-nanocomposites poly (lactic acid) - PLA with bentonite clay. The bio-nanocomposites were produced by melt intercalation with incorporation of 1 to 3 wt% of organoclay. The degree of dispersion of clays in the polymer, and consequently the structure of bio-nanocomposites produced was evaluated by X-ray diffraction (XRD), and the thermal properties were studied by differential scanning calorimetry (DSC). XRD results indicated the formation of intercalated structures. It was observed the appearance of crystalline melting double peaks in bio-nanocomposites PLA.

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.

scholarly journals Calorimetric study on Bi-Cu-Sn alloys

2019 ◽  
Vol 38 (2019) ◽  
pp. 541-546
Author(s):  
Jolanta Romanowska
Keyword(s):  
Differential Scanning Calorimetry ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Temperature Interval ◽  
Energy Dispersive Spectrometer ◽  
Energy Dispersive ◽  
Calorimetric Study ◽  
Calorimetric Investigation ◽  
Scanning Calorimetry ◽  
Scanning Electron

AbstractThe paper presents results of calorimetric investigation of the Bi-Cu-Sn system by means of differential scanning calorimetry (DSC) at the temperature interval 25-1250∘C, Values of liquidus, solidus and invariant reactions temperatures, as well as melting enthalpies of the selected alloys were determined. Microstructure investigation of the alloys were performed by the use of a scanning electron microscope (SEM) equipped with an energy-dispersive spectrometer (EDS).

Thermal Properties and Morphology of Electrospun PEG/PVP Composite Fibers as Novel Phase Change Materials

2012 ◽  
Vol 204-208 ◽  
pp. 3998-4001
Author(s):  
Qi Song Shi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Differential Scanning Calorimetry ◽  
Thermal Properties ◽  
Phase Change ◽  
Phase Change Materials ◽  
Composite Fibers ◽  
Scanning Calorimetry ◽  
Ultrafine Fibers ◽  
Scanning Electron

The ultrafine fibers based on the composites of polyethylene glycol(PEG) and polyvinylpyrrolidone(PVP) were prepared successfully via electrospinning as phase change materials. The thermal properties and morphology of the composite fibers were studied by differential scanning calorimetry(DSC) and scanning electron microscopy(SEM), respectively.

scholarly journals Antistatic and Thermal Properties of Poly(Lactic Acid)/Polypropylene/Carbon Nanotube Nanocomposites

2020 ◽  
Vol 16 (2) ◽  
pp. 57-69
Author(s):  
Wen Shyang Chow ◽  
Yuan Ting Lim
Keyword(s):  
Carbon Nanotubes ◽  
Lactic Acid ◽  
Thermal Properties ◽  
Poly Lactic Acid ◽  
Compression Moulding ◽  
Scanning Calorimetry ◽  
Blend Ratio ◽  
Crystallisation Temperature ◽  
Pp Blends ◽  
Thermal Stability Of

The aim of this study is to investigate the influence of carbon nanotubes (CNT) on the antistatic and thermal properties of poly(lactic acid)/polypropylene/carbon nanotubes (PLA/PP/CNT) nanocomposites. PLA/PP (blend ratio = 60:40) containing CNT (loading 1.0 to 2.5 phr) was melt-compounded followed by compression moulding. The antistatic properties of PLA/PP/CNT nanocomposites achieved at 2.5 phr CNT loading. Thermogravimetric analysis (TGA) results indicated that the thermal stability of PLA/PP/ CNT nanocomposite was higher than PLA/PP blend. Differential Scanning Calorimetry (DSC) results demonstrated that CNT reduced the cold crystallisation temperature of PLA, while increased the crystallisation temperature of PP, which evidenced the nucleatingability of CNT in the PLA/PP blends.

scholarly journals Karakterisasi Paduan AlMgSi Untuk Kelongsong Bahan Bakar U3Si2/Al Densitas Uranium 5,2 gU/cm3

2018 ◽  
Vol 24 (1) ◽  
Author(s):  
Aslina Br. Ginting ◽  
Supardjo Supardjo ◽  
Yanlinastuti Yanlinastuti ◽  
Dian Anggraini ◽  
Boybul Boybul
Keyword(s):  
Thermal Analysis ◽  
Differential Scanning Calorimetry ◽  
Differential Thermal Analysis ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Interface Bonding ◽  
Scanning Calorimetry ◽  
Scanning Electron

Meningkatnya densitas uranium dari 2,96 gU/cm3 menjadi 5,2 gU/cm3 bahan bakar U3Si2/Al harus diikuti dengan penggunaan kelongsong yang kompatibel. Bahan bakar berdensitas tinggi mempunyai kekerasan yang tinggi, sehingga bila menggunakan paduan AlMg2 sebagai kelongsong dapat menyebabkan terjadi dogbone pada saat perolan. Selain fenomena dogbone, pada saat bahan bakar tersebut digunakan di reaktor dapat terjadi swelling karena meningkatnya hasil fisi maupun burn up. Oleh karena itu, perlu dicari pengganti bahan kelongsong untuk bahan bakar U3Si2/Al densitas tinggi. Pada penelitian ini telah dilakukan karakterisasi paduan AlMgSi sebagai kandidat pengganti kelongsong AlMg2. Karakterisasi yang dilakukan meliputi analisis termal, kekerasan, mikrostruktur dan laju korosi. Analisis termal dilakukan menggunakan DTA (Differential Thermal Analysis) dan DSC (Differential Scanning Calorimetry). Analisis kekerasan menggunakan alat uji kekerasan mikro, mikrostruktur menggunakan SEM (Scanning Electron Microscope) dan analisis laju korosi dilakukan dengan pemanasan pada temperatur 150 oC selama 77 jam di dalam autoclave. Hasil analisis menunjukkan bahwa kelongsong AlMgSi maupun AlMg2 mempunyai kompatibilitas panas dengan bahan bakar U3Si2/Al cukup stabil hingga temperatur 650 oC. Kelongsong AlMgSi mempunyai kekerasan sebesar 115 HVN dan kelongsong AlMg2 sebesar 70,1 HVN. Sementara itu, analisis mikrostruktur menunjukkan bahwa morfologi ikatan antarmuka (interface bonding) kelongsong AlMgSi lebih baik dari kelongsong AlMg2, demikian halnya dengan laju korosi bahwa kelongsong AlMgSi mempunyai laju korosi lebih kecil dibanding kelongsong AlMg2. Hasil karakterisasi termal, kekerasan, mikrostruktur dan laju korosi menunjukkan bahwa PEB U3Si2/Al densitas 5,2 gU/cm3 menggunakan kelongsong AlMgSi lebih baik dibanding PEB U3Si2/Al  densitas 5,2 gU/cm3  menggunakan kelongsong AlMg2.Kata kunci: U3Si2/Al, densitas 5,2 gU/cm3, kelongsong AlMgSi dan AlMg2.

Effect of Wood Flour Addition on Warm/Cool Feeling of Green Composite

2021 ◽  
Vol 320 ◽  
pp. 126-130
Author(s):  
Hideaki Katogi ◽  
Hisako Tsunekawa ◽  
Ayaka Takata
Keyword(s):  
Heat Flux ◽  
Lactic Acid ◽  
Electron Microscope ◽  
Wood Flour ◽  
Poly Lactic Acid ◽  
Green Composite ◽  
Maximum Value ◽  
Humidity Chamber ◽  
Void Area ◽  
Scanning Electron

In this study, effect of wood flour addition on warm/cool feeling of green composite using wood flour and poly(lactic acid) was investigated for comfortability of interior product. Additive amounts of wood flour were 10 – 40 wt.%. Measurement of initial maximum values of heat flux of green composite using wood flour was conducted under constant temperature and humidity chamber. Surface of green composite using wood flour was observed by Scanning Electron Microscope (SEM). Following conclusions were obtained. The initial maximum value of heat flux of green composite decreased with an increase of wood flour additive amount until 20 wt.%. But, initial maximum value of heat flux of green composite at more than wood flour additive amount 30 wt.% almost did not change. From SEM observation, the appearance void area on surface of green composite at wood flour additive amount 20 wt.% was larger than that of green composite at wood flour additive amount 10 wt.%. Therefore, initial maximum value of heat flux of green composite was mainly affected because of increase of void area and wood flour until wood flour additive amount 20 wt.%.

Temperature-Regulating Properties of Phase Change Fiber Blended Knitted Fabrics after Laundering

2011 ◽  
Vol 393-395 ◽  
pp. 397-400
Author(s):  
Wei Lai Chen ◽  
Miao Miao He ◽  
Ying Gao ◽  
Xia Wu
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Differential Scanning Calorimetry ◽  
Thermal Properties ◽  
Retention Rate ◽  
Cooling Process ◽  
Scanning Calorimetry ◽  
Knitted Fabrics ◽  
Dsc Analyses ◽  
Scanning Electron

In order to study the temperature- regulating properties of cotton/mercerized wool/Outlast fiber 50/10/40 blended knitted fabrics after laundering, Scanning electron microscopy (SEM) and Differential scanning calorimetry (DSC) analyses were used to test the thermal properties of the fabrics by varying washing cycles. The results show that the enthalpy of fabrics reduces with the increase of washing cycles. Enthalpy retention rate of fabrics is more than 89% after 30 cycles washing, and still above 80% after 50 cycles washing in cooling process.

Preparation of Poly(Vinylidene Fluoride)/Silica Composite Nanofiber by Electrospinning Technique

2015 ◽  
Vol 804 ◽  
pp. 84-87 ◽  
Author(s):  
Moragote Buddhakala ◽  
Anchan Muakngam
Keyword(s):  
Differential Scanning Calorimetry ◽  
Electron Microscope ◽  
Mixed Solvent ◽  
Vinylidene Fluoride ◽  
Composite Membranes ◽  
Scanning Calorimetry ◽  
Electrospinning Technique ◽  
Composite Nanofiber ◽  
Poly Vinylidene Fluoride ◽  
Scanning Electron

A composite nanofiber containing poly (vinylidene fluoride) (PVDF) and silica (SiO2) were prepared by electrospinning of their mixtrues.The various amount of SiO2 nanoparticle was add with 15 wt.% PVDF solution in mixed solvent of N,N-dimethylacetamine (DMAc) : acetone at a ratio of 4:6 with the applied voltage of 8 kV, tip to collector distance of 10 cm and flow rate of 1 ml/hr. The morphology of the PVDF/SiO2 membranes was investigated by scanning electron microscope (SEM). The effect of SiO2 concentration on the morphology of the composite membranes were discussed. Crystallinity of the composite membranes was investigated by differential scanning calorimetry (DSC). It was found that SiO2 concentration have significant influence on the morphology and crystallinity of PVDF/SiO2 membranes.

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.

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