Transmission FT-IR Study on the Adsorption and Reactions of Lactic Acid and Poly(lactic acid) on TiO2

2010 ◽  
Vol 114 (41) ◽  
pp. 17720-17727 ◽  
Author(s):  
Yi-Kwan Chen ◽  
Yu-Feng Lin ◽  
Zih-Wei Peng ◽  
Jong-Liang Lin
Keyword(s):  
Lactic Acid ◽  
Poly Lactic Acid ◽  
Ft Ir ◽  
Ir Study

Formation of Hydroxycarbonate Apatite Layer on Poly(Lactic Acid) Composites in Simulated Body Fluid

2005 ◽  
Vol 284-286 ◽  
pp. 489-492 ◽  
Author(s):  
Hirotaka Maeda ◽  
Toshihiro Kasuga ◽  
Masayuki Nogami
Keyword(s):  
Lactic Acid ◽  
Simulated Body Fluid ◽  
Zeta Potential ◽  
Calcium Chloride ◽  
Composite Membrane ◽  
Body Fluid ◽  
Poly Lactic Acid ◽  
Zeta Potentials ◽  
Carbonate Ion ◽  
Ft Ir

Hydroxycarbonate apatite (HCA), which formed on a poly(lactic acid) (PLA) composite membrane containing vaterite or calcium chloride after soaking in simulated body fluid, was examined to clarify the importance of the ceramic phases in the composites. FT-IR spectra showed that the ratio of CO3/PO4 in the infrared adsorption bands of HCA formed on the PLA composite containing vaterite was much larger than that of HCA formed on the PLA composite containing calcium chloride. Substitution of carbonate ion in hydroxyapatite is believed to be strongly influenced by ceramic phases in the composites. The zeta potentials of HCA formed on the PLA composite containing vaterite or calcium chloride was -6 mV or -17 mV, respectively. The zeta potential may be influenced by the amount of carbonate ion in hydroxyapatite.

scholarly journals Preparations of Poly(lactic acid) Dispersions in Water for Coating Applications

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2767
Author(s):  
Giada Belletti ◽  
Sara Buoso ◽  
Lucia Ricci ◽  
Alejandro Guillem-Ortiz ◽  
Alejandro Aragón-Gutiérrez ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Gel Permeation Chromatography ◽  
Sem Analysis ◽  
Water Phase ◽  
Poly Lactic Acid ◽  
Water Emulsion ◽  
Preparation Conditions ◽  
Ft Ir ◽  
Homogenization Methods ◽  
Oil In Water Emulsion

A green, effective methodology for the preparation of water-based dispersions of poly(lactic acid) (PLA) for coating purposes is herein presented. The procedure consists of two steps: in the first one, an oil-in-water emulsion is obtained by mixing a solution of PLA in ethyl acetate with a water phase containing surfactant and stabilizer. Different homogenization methods as well as oil/water phase ratio, surfactant and stabilizer combinations were screened. In the second step, the quantitative evaporation of the organic provides water dispersions of PLA that are stable, at least, over several weeks at room temperature or at 4 °C. Particle size was in the 200–500 nm range, depending on the preparation conditions, as confirmed by scanning electron microscope (SEM) analysis. PLA was found not to suffer significant molecular weight degradation by gel permeation chromatography (GPC) analysis. Furthermore, two selected formulations with glass transition temperature (Tg) of 51 °C and 34 °C were tested for the preparation of PLA films by drying in PTFE capsules. In both cases, continuous films that are homogeneous by Fourier-transform infrared spectroscopy (FT-IR) and SEM observation were obtained only when drying was performed above 60 °C. The formulation with lower Tg results in films which are more flexible and transparent.

Characterization of Electrospun Poly(Lactic Acid)/polyaniline Blend Nanofibers

2011 ◽  
Vol 332-334 ◽  
pp. 317-320 ◽  
Author(s):  
Hui Qin Zhang
Keyword(s):  
Lactic Acid ◽  
Composite Nanofibers ◽  
Weight Ratio ◽  
Electrospinning Process ◽  
Poly Lactic Acid ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Ft Ir

In this study, composite nanofibers of polyaniline doped with dodecylbenzene sulfonic acid (PANI-DBSA) and Poly(lactic acid) (PLA) were prepared via an electrospinning process. The surface morphology, thermal properties and crystal structure of PLA/PANI-DBSA nanofibers are characterized using Fourier transform infrared spectroscopy (FT-IR), wide-angle x-ray diffraction (WAXD) and scanning electron microscopy (SEM). SEM images showed that the morphology and diameter of the nanofibers were affected by the weight ratio of blend solution.

Rheo-optical FT-IR spectroscopy of poly(3-hydroxybutyrate)/poly(lactic acid) blend films

2009 ◽  
Vol 49 (2) ◽  
pp. 284-287 ◽  
Author(s):  
Christian Vogel ◽  
Günter G. Hoffmann ◽  
Heinz W. Siesler
Keyword(s):  
Lactic Acid ◽  
Ir Spectroscopy ◽  
Poly Lactic Acid ◽  
Blend Films ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

Preparation and Characterization of Poly(lactic acid) with Different Molecular Weights by Thermal Hydrolysis

2013 ◽  
Vol 440 ◽  
pp. 19-24 ◽  
Author(s):  
Jun Yan Yao ◽  
Loogn Tak Lim ◽  
Yu Jie Li
Keyword(s):  
Molecular Weight ◽  
Lactic Acid ◽  
Hydroxyl Group ◽  
Poly Lactic Acid ◽  
Thermal Hydrolysis ◽  
Molecular Weights ◽  
Hydrolytic Reaction ◽  
Structures And Properties ◽  
Ft Ir

A feasible and effective method of thermal hydrolysis to prepare poly (lactic acid) (PLA) oligomers with different controlled molecular weight from PLA is presented in this paper. The thermal hydrolytic reaction was carried out by immerging PLA resin pellets in boiling distilled water for a certain period of time. Ester groups in PLA chains are hydrolytically degraded in the presence of water and thermal, so PLA oligomers with different molecular weight were prepared. The structures and properties of PLA oligomers were characterized by FT-IR, GPC, DSC, etc. The results showed that thermal hydrolytic reaction could effectively reduce the molecular weight of PLA, which declines with the increase of the thermal hydrolytic reaction time. Meanwhile, the content of terminal hydroxyl group, glass transition temperature, melting point of PLA oligomers prepared from thermal hydrolytic reactions exhibit gradual changes with the extension of the thermal hydrolytic time.

scholarly journals Preparation of Higher Molecular Weight Poly (L-lactic Acid) by Chain Extension

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Chenguang Liu ◽  
Yuliang Jia ◽  
Aihua He
Keyword(s):  
Molecular Weight ◽  
Lactic Acid ◽  
Average Molecular Weight ◽  
Hexamethylene Diisocyanate ◽  
Chain Extension ◽  
Poly Lactic Acid ◽  
Weight Changes ◽  
H Nmr ◽  
Left Handed ◽  
Ft Ir

High molecular weight poly (lactic acid) (PLA) was obtained by chain extending with hexamethylene diisocyanate (HDI). The influences of the amount of chain extender, reaction time, and molecular weight changes of prepolymers on the poly(lactic acid) were investigated. PLA prepolymer with a viscosity, average molecular weight (Mη) of 2 × 104 g/mol was synthesized froml-lactide using stannous octoate as the catalyst. After 20 min of chain extension at 175°C, the resulting polymer hadMwof 20.3 × 104 g/mol andMnof 10.5 × 104 g/mol. Both FT-IR and1H-NMR verified that the structure of PLA did not change either before chain extending or after. The optically active characterized that the chain extending-product was left handed. DSC and XRD results showed that both theTgand the crystallinity of PLA were lowered by chain-extension reaction. The crystalline transformation happened in PLA after chain extending, crystallineα′form toαform.

Characterization of Tri-(1, 4-Butanediol Single-Butyrate) Citrate as a New Plasticizer for Poly(Lactic Acid)

2013 ◽  
Vol 706-708 ◽  
pp. 32-35
Author(s):  
Tong Wan ◽  
Tao Du ◽  
Si Zhang
Keyword(s):  
Lactic Acid ◽  
Shear Rate ◽  
Parallel Plate ◽  
Chemical Structure ◽  
Poly Lactic Acid ◽  
Ft Ir

Tri-(1, 4-butanediol single-butyrate) citrate (TBBC) was synthesized as a new plasticizer for PLA. The chemical structure of TBBC was characterized by FT-IR. PLA was plasticized with various amount of TBBC. The effects of both temperature and shear rate on the rheologies of PLA/TBBC blends were evaluated by a parallel plate rheometer.

scholarly journals Stereocomplex Poly(Lactic Acid) Amphiphilic Conetwork Gel with Temperature and pH Dual Sensitivity

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1940 ◽  
Author(s):  
Jie Wu ◽  
Xiaoyu Shi ◽  
Zhidan Wang ◽  
Fei Song ◽  
Wenli Gao ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Lactic Acid ◽  
Radical Copolymerization ◽  
Ph Sensitivity ◽  
Proton Nuclear Magnetic Resonance ◽  
Poly Lactic Acid ◽  
X Ray Diffraction ◽  
Free Radical Copolymerization ◽  
Good Thermal Stability ◽  
Ft Ir

A novel stereocomplex poly(lactic acid) amphiphilic conetwork gel with temperature and pH dual sensitivity was synthesized by ring-opening polymerization (ROP) and free radical copolymerization. The chemical structure and composition of hydrogel were characterized by Fourier transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance (1H NMR) and X-ray diffraction (XRD). The temperature and pH sensitivity and good amphiphilicity of hydrogel were studied using digital photos, the swelling ratios and a scanning electron microscope (SEM). The thermal stability and mechanical properties of hydrogel were studied by differential scanning calorimeter (DSC) and dynamic viscoelastic spectrometer. The results indicated that the hydrogel has amphiphilicity, temperature and pH sensitivity, good thermal stability and mechanical strength.

Properties of Poly(Lactic Acid) Blended with Natural Rubber-Graft- Poly(Acrylic Acid)

2020 ◽  
Vol 845 ◽  
pp. 45-50
Author(s):  
Thamolwan Udomkitpanya ◽  
Kawee Srikulkit
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Acrylic Acid ◽  
Natural Rubber ◽  
Impact Testing ◽  
Poly Lactic Acid ◽  
Scanning Calorimetry ◽  
Ft Ir ◽  
Internal Mixer ◽  
Poly Acrylic Acid

Poly(acrylic acid) (PAA) was grafted onto natural rubber (NR) to improve the compatibility of NR and poly(lactic acid) (PLA). Polymer blend between PLA and NR-g-PAA was prepared by an internal mixer. Fourier-transform infrared spectroscopy (FT-IR), tensile testing, impact testing, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) were employed to determine the functional group, mechanical properties and thermal properties of blends, respectively. Results showed that the addition of NR-g-PAA significantly improved the elongation, impact strength and thermal stability of blends. The P70N30 was the optimum composition to obtain improved mechanical properties of PLA.

Preparation and Properties of Nanocomposites Based on Poly(Lactic Acid) and Modified TiO2

2012 ◽  
Vol 463-464 ◽  
pp. 519-522 ◽  
Author(s):  
Achanai Buasri ◽  
Nattawut Chaiyut ◽  
Chanon Kritsanakun ◽  
Chettha Phatkun ◽  
Tiwiwan Khunsri
Keyword(s):  
Lactic Acid ◽  
Propionic Acid ◽  
Uv Irradiation ◽  
Nano Particles ◽  
Poly Lactic Acid ◽  
Nano Composites ◽  
Nano Particle ◽  
High Transparency ◽  
Wide Range ◽  
Ft Ir

In this study, poly (lactic acid) (PLA)-TiO2nano particle nano composites were prepared and the severe aggregation of TiO2nano particles in polymer matrixwere reduced by themodification of TiO2surface with propionic acid and n-hexylamine. The resulting products were characterized by FT-IR, DSCand SEMtechniques so as to have a better understanding of bondingbetween the polymer and nano particles. All of nano composites with a wide range of TiO2additionexhibit the high transparency. SEM micrographs of the nano composites showed of the TiO2nano particles were uniformly dispersed in polymer matrices. Photodegradation of PLA-TiO2nano particle nano composites were also investigated. The results indicated that nano composites could be efficiently photodegraded by UV irradiation in comparison with pure PLA.

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