scholarly journals Development of Biodegradable Flame-Retardant Bamboo Charcoal Composites, Part II: Thermal Degradation, Gas Phase, and Elemental Analyses

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2238 ◽  
Author(s):  
Shanshan Wang ◽  
Liang Zhang ◽  
Kate Semple ◽  
Min Zhang ◽  
Wenbiao Zhang ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Thermal Degradation ◽  
Flame Retardant ◽  
Gas Phase ◽  
Protective Layer ◽  
Fourier Transform Infrared ◽  
Infrared Spectrometry ◽  
Bamboo Charcoal ◽  
Scanning Calorimetry ◽  
X Ray

Bamboo charcoal (BC) and aluminum hypophosphite (AHP) singly and in combination were investigated as flame-retardant fillers for polylactic acid (PLA). A set of BC/PLA/AHP composites were prepared by melt-blending and tested for thermal and flame-retardancy properties in Part I. Here, in Part II, the results for differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Fourier transform infrared (FTIR), thermogravimetry-Fourier transform infrared spectrometry (TG-FTIR), X-ray diffraction (XRD), and X-ray photoelectron analysis (XPS) are presented. The fillers either singly or together promoted earlier initial thermal degradation of the surface of BC/PLA/AHP composites, with a carbon residue rate up to 40.3%, providing a protective layer of char. Additionally, BC promotes heterogeneous nucleation of PLA, while AHP improves the mechanical properties and machinability. Gaseous combustion products CO, aromatic compounds, and carbonyl groups were significantly suppressed in only the BC-PLA composite, but not pure PLA or the BC/PLA/AHP system. The flame-retardant effects of AHP and BC-AHP co-addition combine effective gas-phase and condensed-phase surface phenomena that provide a heat and oxygen barrier, protecting the inner matrix. While it generated much CO2 and smoke during combustion, it is not yet clear whether BC addition on its own contributes any significant gas phase protection for PLA.

scholarly journals Synthesis of Novel Arginine-Based Flame Retardant and Its Application in Lyocell Fabric

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3588
Author(s):  
Jiayi Chen ◽  
Yansong Liu ◽  
Jiayue Zhang ◽  
Yuanlin Ren ◽  
Xiaohui Liu
Keyword(s):  
Fourier Transform ◽  
Heat Release ◽  
Flame Retardant ◽  
Photoelectron Spectroscopy ◽  
Fourier Transform Infrared ◽  
Ftir Analysis ◽  
Excellent Thermal Stability ◽  
X Ray ◽  
Cone Calorimeter Test ◽  
Before And After

Lyocell fabrics are widely applied in textiles, however, its high flammability increases the risk of fire. Therefore, to resolve the issue, a novel biomass-based flame retardant with phosphorus and nitrogen elements was designed and synthesized by the reaction of arginine with phosphoric acid and urea. It was then grafted onto the lyocell fabric by a dip-dry-cure technique to prepare durable flame-retardant lyocell fabric (FR-lyocell). X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR) analysis demonstrated that the flame retardant was successfully introduced into the lyocell sample. Thermogravimetric (TG) and Raman analyses confirmed that the modified lyocell fabric featured excellent thermal stability and significantly increased char residue. Vertical combustion results indicated that FR-lyocell before and after washing formed a complete and dense char layer. Thermogravimetric Fourier-transform infrared (TG-FTIR) analysis suggested that incombustible substances (such as H2O and CO2) were produced and played a significant fire retarding role in the gas phase. The cone calorimeter test corroborated that the peak of heat release rate (PHRR) and total heat release (THR) declined by 89.4% and 56.4%, respectively. These results indicated that the flame retardancy of the lyocell fabric was observably ameliorated.

scholarly journals COMPARISON STUDY OF GRINDING AND SLURRY METHOD ON PHYSICOCHEMICAL CHARACTERISTIC OF ACYCLOVIR – SUCCINIC ACID COCRYSTAL

2017 ◽  
Vol 10 (3) ◽  
pp. 153
Author(s):  
Fauzi Rahman ◽  
Agnes Nuniek Winantari ◽  
Dwi Setyawan ◽  
Siswandono .
Keyword(s):  
Fourier Transform ◽  
Ir Spectroscopy ◽  
Succinic Acid ◽  
Physicochemical Characteristic ◽  
Fourier Transform Infrared ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Slurry Method ◽  
Dissolution Efficiency

ABSTRACTObjective: This study aimed to compare the characteristics of acyclovir (ACV)-succinic acid (SA) cocrystal with grinding and slurry method.Methods: Cocrystals were prepared using grinding and slurry methods. Physicochemical characterizations were performed using powder X-raydiffraction (PXRD), differential scanning calorimetry, Fourier transform infrared (IR) spectroscopy, scanning electron microscope (SEM), anddissolution test.Results: The study revealed that cocrystal of ACV-SA showed a decrease in the melting temperature, i.e., 175.10°C, respectively, in comparison with themelting point of the constituent materials (ACV 253.53°C and SA 187.29°C). PXRD diffractogram showed that cocrystal with grinding method exhibitednew diffraction peaks at angle 2θ=8.92°, 16.24°, and 17.14°, while PXRD diffractogram of cocrystal with slurry method exhibit new diffraction peaksat angle 2θ=16.25°, and 19.63°. Characterization with IR spectroscopy showed the disappearance of transmission peaks at 3441cm disappearance ofC=O stretch at 1584cm and 1612cm. Dissolution efficiency of each treatment group calculated the efficiency of dissolution in 15th minutes, grindingmethod cocrystal with grinding time 15 minutes give the dissolution efficiency were 54.23%. Slurry method cocrystal with solvent concentration12 ml/g gives the high value of the dissolution efficiency is 74.36%. SEM micrographs showed that cocrystals prepared by solvent evaporation methodhave differences crystal form at magnification 5000× magnification compared to pure ACV and physical mixture.Conclusion: The study concluded that cocrystals of ACV-SA were successfully formed using grinding and slurry methods. The formed cocrystalsof ACV-SA exhibited different physicochemical characteristics as compared to the constituent materials. The formed cocrystals prepared by slurrymethod have a high intensity of diffraction peak on X-ray diffraction and highest dissolution efficiency at 15 minutes rather than grinding methodcocrystal.Keywords: Cocrystal, Acyclovir, Succinic acid, Grinding, Slurry, Powder X-ray diffraction, Fourier transform infrared, Dissolution rate. 

193 IN VITRO DEVELOPMENT OF A LESS INVASIVE HORMONE DELIVERY SYSTEM TO SUPEROVULATE TIGERS

2010 ◽  
Vol 22 (1) ◽  
pp. 255
Author(s):  
J. T. Aaltonen ◽  
S. Singh ◽  
L. R. Fogueri ◽  
N. S. Mulla ◽  
N. M. Loskutoff
Keyword(s):  
Differential Scanning Calorimetry ◽  
Fourier Transform ◽  
Benzyl Alcohol ◽  
Release Rate ◽  
Fourier Transform Infrared ◽  
Release Profile ◽  
Infrared Spectrometry ◽  
Burst Release ◽  
Fourier Transform Infrared Spectrometry ◽  
Scanning Calorimetry

Current administration of FSH for the purpose of superovulation of tigers is achieved through serial injections or subcutaneous osmotic pump (Blevins B et al. 2009 J. Reprod. Fertil. 21, 153 abst). Both have limitations, which are pulsatile hormone fluctuations and multiple anesthesia events for pump insertion and removal, respectively. In vivo attempts to superovulate tigers using aluminum hydroxide gel [Al(OH)3] proved unsuccessful by fecal hormone enzyme immunoassay. In addition, Al(OH)3 raises the potential for an immune response to foreign FSH. An inert, biodegradable, and FDA-approved polylactide-co-glycolide polymer-based in situ gel forming system eliminates the problems above with a single injection delivery, allowing a more natural sustained release of FSH. Polymer solutions were made using a solvent mixture of benzyl benzoate (BB), or benzyl alcohol (BA), or both. Porcine FSH (Folltropin®-V, Bioniche, Belleville, Ontario, Canada) was incorporated into the polymer solution via sonication, which gelled upon contact with interstitial fluid. Polymer composition (ratio of lactide to glycolide) and concentration and ratio of BB to BA parameters can be manipulated to achieve a desired release profile. Two formulations (F1 and F2) were created with differing percentages of composition for the purpose of recreating a controlled release rate of 100 NIH-FSH-P1 reference standard mg/day (pump output). The FSH polymer was injected into 15 mL of PBS (pH 7.4 in a 37°C shaker bath at 30 rpm), which instantly formed a gel. One milliliter of PBS was sampled every 24 h and replenished with fresh PBS. The amount of FSH was determined by measuring UV absorbance at 290 nm (Shimadzu 1600 UV-visible spectrophotometer; Shimadzu Scientific Instruments, Columbia, MD, USA). Formulation F1 showed a higher initial burst release than F2 (61.5% v. 35.8% of total incorporated hormone) as a result of the use of 100% BA as a solvent. Benzyl alcohol is more hydrophilic than BB, leaching out of the polymer-FSH solution faster and leading to a greater release of the hydrophilic FSH. Both formulations showed a biphasic release pattern in which the first phase was relatively faster than the second phase. Although F2 (80% BA-20% BB solvent) was successful in reducing the burst release by half, the day-to-day profile is below target. Our results indicate that F2 has a better release profile than F1 for inducing folliculogenesis and can be improved by manipulating formulation parameters such as increasing the polymer concentration and BA:BB ratio of the solvents. Using Fourier transform infrared spectrometry and differential scanning calorimetry, hormones before gel incorporation were compared to those released. Fourier transform infrared spectrometry and differential scanning calorimetry data suggest that the gel does not affect the conformational stability of FSH. It is therefore possible to manipulate a gel to mimic the release rate of a proven osmotic pump without compromising the functionality of the protein hormone, potentially reducing the number of surgeries or injections to superovulate tigers.

Photolysis of .alpha.-diazo ketones in the gas phase monitored by Fourier-transform infrared spectrometry

1983 ◽  
Vol 48 (4) ◽  
pp. 533-537 ◽  
Author(s):  
Claude Marfisi ◽  
Patrick Verlaque ◽  
Gisele Davidovics ◽  
Jean Pourcin ◽  
Louis Pizzala ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Gas Phase ◽  
Fourier Transform Infrared ◽  
Infrared Spectrometry ◽  
Fourier Transform Infrared Spectrometry

scholarly journals Preparation, Characterization, and In Vivo Evaluation of Amorphous Icaritin Nanoparticles Prepared by a Reactive Precipitation Technique

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2913
Author(s):  
Cheng Tang ◽  
Kun Meng ◽  
Xiaoming Chen ◽  
Hua Yao ◽  
Junqiong Kong ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Oral Bioavailability ◽  
Fourier Transform Infrared ◽  
Water Soluble ◽  
Phase Iii ◽  
Infrared Spectrometry ◽  
Scanning Calorimetry ◽  
In Vivo Evaluation ◽  
Oh Groups ◽  
Precipitation Technique

Icaritin is a promising anti-hepatoma drug that is currently being tested in a phase-III clinical trial. A novel combination of amorphization and nanonization was used to enhance the oral bioavailability of icaritin. Amorphous icaritin nanoparticles (AINs) were prepared by a reactive precipitation technique (RPT). Fourier transform infrared spectrometry was used to investigate the mechanism underlying the formation of amorphous nanoparticles. AINs were characterized via scanning electron microscopy, X-ray powder diffraction, and differential scanning calorimetry. Our prepared AINs were also evaluated for their dissolution rates in vitro and oral bioavailability. The resultant nanosized AINs (64 nm) were amorphous and exhibited a higher dissolution rate than that derived from a previous oil-suspension formulation. Fourier transform infrared spectroscopy (FTIR) revealed that the C=O groups from the hydrophilic chain of polymers and the OH groups from icaritin formed hydrogen bonds that inhibited AIN crystallization and aggregation. Furthermore, an oral administration assay in beagle dogs showed that Cmax and AUClast of the dried AINs formulation were 3.3-fold and 4.5-fold higher than those of the oil-suspension preparation (p < 0.01), respectively. Our results demonstrate that the preparation of amorphous drug nanoparticles via our RPT may be a promising technique for improving the oral bioavailability of poorly water-soluble drugs.

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