scholarly journals Strong Effect of Process Parameters on the Properties of Boron-Containing Phenolic Resins with High Char Yield

2020 ◽  
Vol 10 (4) ◽  
pp. 1408 ◽  
Author(s):  
Yu Sun ◽  
Yuguo Sun
Keyword(s):  
Surface Tension ◽  
Reaction Time ◽  
Carbon Fibers ◽  
Process Parameters ◽  
Char Yield ◽  
Phenolic Resins ◽  
Molar Ratios ◽  
Potassium Borate ◽  
Critical Process Parameters ◽  
First Time

This work is focused on the optimization of critical process parameters for preparation of boron-containing phenolic resin (B-containing PR), including the molar ratios of formaldehyde/phenol and potassium borate/phenol, reaction time; and measurement of surface tension of B-containing PR solution and wettability between B-containing PR solution and carbon fibers. The effects of the formaldehyde/phenol and potassium borate/phenol molar ratios on the char yield of the B-containing PR was studied. The highest char yield of B-containing PR could be as high as 71% under optimal conditions (molar ratios of formaldehyde/phenol = 1.8 and potassium borate/phenol = 0.2, and reaction time = 13 h). The effect of concentration and tested temperature on the surface tension of B-containing PR solution was investigated, and the wettability between B-containing PR solution and carbon fibers was evaluated for the first time, providing useful theory and experimental data for the preparation of B-containing PR-based composites.

scholarly journals Interactions between an Associative Amphiphilic Block Polyelectrolyte and Surfactants in Water: Effect of Charge Type on Solution Properties and Aggregation

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1729
Author(s):  
Patrizio Raffa
Keyword(s):  
Surface Tension ◽  
Self Assembly ◽  
Interaction Model ◽  
Industrial Applications ◽  
Molecular Organization ◽  
Different Types ◽  
Solution Rheology ◽  
Interesting Class ◽  
First Time

The study of interactions between polyelectrolytes (PE) and surfactants is of great interest for both fundamental and applied research. These mixtures can represent, for example, models of self-assembly and molecular organization in biological systems, but they are also relevant in industrial applications. Amphiphilic block polyelectrolytes represent an interesting class of PE, but their interactions with surfactants have not been extensively explored so far, most studies being restricted to non-associating PE. In this work, interactions between an anionic amphiphilic triblock polyelectrolyte and different types of surfactants bearing respectively negative, positive and no charge, are investigated via surface tension and solution rheology measurements for the first time. It is evidenced that the surfactants have different effects on viscosity and surface tension, depending on their charge type. Micellization of the surfactant is affected by the presence of the polymer in all cases; shear viscosity of polymer solutions decreases in presence of the same charge or nonionic surfactants, while the opposite charge surfactant causes precipitation. This study highlights the importance of the charge type, and the role of the associating hydrophobic block in the PE structure, on the solution behavior of the mixtures. Moreover, a possible interaction model is proposed, based on the obtained data.

scholarly journals Designing ultra-small nanostructured lipid carriers: critical process parameters

2020 ◽  
Author(s):  
Maria Mendes ◽  
João Basso ◽  
João Sousa ◽  
Alberto Pais ◽  
Carla Vitorino
Keyword(s):  
Process Parameters ◽  
Nanostructured Lipid Carriers ◽  
Critical Process Parameters ◽  
Critical Process

Synthesis of a Ruthenium Complex Based on 2,6-Bis[1-(Pyridin-2-yl)-1H-Benzo[d]Imidazol-2-yl]Pyridine and Catalytic Oxidation of (1H-Benzo[d]-Imidazol-2-yl)Methanol to 1H-Benzo[d]Imidazole-2-Carbaldehyde with H2O2

2017 ◽  
Vol 41 (2) ◽  
pp. 88-92
Author(s):  
Shenggui Liu ◽  
Rongkai Pan ◽  
Wenyi Su ◽  
Guobi Li ◽  
Chunlin Ni
Keyword(s):  
Reaction Time ◽  
Catalytic Oxidation ◽  
Reaction Temperature ◽  
Ruthenium Complex ◽  
Reaction Conditions ◽  
Molar Ratios ◽  
Optimal Reaction

2,6-Bis[1-(pyridin-2-yl)-1H-benzo[d]-imidazol-2-yl]pyridine (bpbp), which has been synthesised by intramolecular thermocyclisation of N2,N6-bis[2-(pyridin-2-ylamino)phenyl]pyridine-2,6-dicarboxamide, reacts with sodium pyridine-2,6-dicarboxylate (pydic) and RuCl3 to give [Ru(bpbp)(pydic)] which can catalyse the oxidation of (1H-benzo[d]imidazol-2-yl)methanol to 1H-benzo[d]imidazole-2-carbaldehyde by H2O2. The optimal reaction conditions were: molar ratios of catalyst to substrate to H2O2 set at 1: 1000: 3000; reaction temperature 50 °C; reaction time 5 h. The yield of (1H-benzo[d]imidazol-2-yl) methanol was 70%.

scholarly journals Application of Statistical Design to Assess the Critical Process Parameters of Ethanol Injection Method for the Preparation of Liposomes

2019 ◽  
Vol 18 (1) ◽  
pp. 103-111 ◽  
Author(s):  
Sayani Bhattacharyya ◽  
Bharani S Sogali
Keyword(s):  
Particle Size ◽  
Process Parameters ◽  
Particle Size Analysis ◽  
Polydispersity Index ◽  
Size Analysis ◽  
Ethanol Injection ◽  
Injection Method ◽  
Critical Process Parameters ◽  
Critical Process ◽  
Ethanol Injection Method

In the present study custom screening design was employed to observe the effect of four critical process parameters on particle size and polydispersity index of the liposomal formulation made by ethanol injection method. The four process parameters selected were lipid ratio, rate of injection, phase volume ratio and rotational speed of magnetic stirring. Eight different liposomal formulations were prepared using the design. The formulations were subjected to particle size analysis. The analysis was done at a significance level p<0.05 and found that the process parameters had significant effect on the particle size and polydispersity index of the formulations. The design was optimized for the individual responses with an overall desirability of more than 50%. Three batches of liposomes were formulated at optimized process parameters which matched the target as predicted by the design. Therefore, it can be concluded that the design was effective in production of nano sized stable monodisperse liposomes by ethanol injection method. Dhaka Univ. J. Pharm. Sci. 18(1): 103-111, 2019 (June)

scholarly journals A study on surface morphology and tension in laser powder bed fusion of Ti-6Al-4V

2020 ◽  
Vol 111 (9-10) ◽  
pp. 2891-2909
Author(s):  
Mahyar Khorasani ◽  
AmirHossein Ghasemi ◽  
Umar Shafique Awan ◽  
Elahe Hadavi ◽  
Martin Leary ◽  
...  
Keyword(s):  
Surface Tension ◽  
Process Parameters ◽  
Surface Profile ◽  
Test Case ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Data Set ◽  
Powder Bed ◽  
Case Morphology ◽  
Melting Pool

Abstract When reporting surface quality, the roughest surface is a reference for the measurements. In LPBF due to recoil pressure and scan movement, asymmetric surface is shaped, and surface roughness has different values in different measurement orientations. In this research, the influence of the laser powder bed fusion (LPBF) process parameters on surface tension and roughness of Ti-6AI-4 V parts in three orientations are investigated. To improve the mechanical properties, heat treatment was carried out and added to the designed matrix to generate a comprehensive data set. Taguchi design of experiment was employed to print 25 samples with five process parameters and post-processing. The effect and interaction of the parameters on the formation of surface profile comprising tension, morphology and roughness in various directions have been analysed. The main contribution of this paper is developing a model to approximate the melting pool temperature and surface tension based on the process parameters. Other contributions are an analysis of process parameters to determine the formation and variation of surface tension and roughness and explain the governing mechanisms through rheological phenomena. Results showed that the main driving factors in the variation of surface tension and formation of the surface profile are thermophysical properties of the feedstock, rheology and the temperature of the melting pool. Also, the results showed that while the value of surface tension is the same for each test case, morphology and the value of roughness are different when analysing the surface in perpendicular, parallel and angled directions to laser movement.

scholarly journals Esterification of Crude Palm Oil Using H2SO4 and Transesterification Using CaO Catalyst Derived from Anadara granosa

2017 ◽  
Vol 17 (2) ◽  
pp. 309 ◽  
Author(s):  
Nurhayati Nurhayati ◽  
Sofia Anita ◽  
Tengku Ariful Amri ◽  
Amilia Linggawati
Keyword(s):  
Reaction Time ◽  
Reaction Temperature ◽  
Palm Oil ◽  
Reaction Times ◽  
Crude Palm Oil ◽  
Process Step ◽  
Molar Ratios ◽  
One Step ◽  
Esterification Reactions ◽  
Anadara Granosa

In this study biodiesel was produced from crude palm oil through two-step processes, namely esterification reactions using homogeneous H2SO4 catalyst and transesterification using the heterogeneous base CaO catalyst derived from Anadara granosa shell. Several parameters affecting to the yields of biodiesel were investigated including the amount of the catalysts, the molar ratios of oil to methanol, reaction times and reaction temperatures. The CaO catalyst was prepared by calcining the A. granosa shells at the temperatures of 800 and 900 °C for 10 h. The as-synthesized biodiesel was analyzed using GC and its characteristics were determined and the results were compared to Standard National for Biodiesel (SNI 04-7183-2006). The optimum condition for the esterification process (step 1) was as follows: reaction temperature of 65 °C, reaction time of 3 h and mol ratio of oil to methanol 1:24. For the transesterification (step 2) the optimum conditions were attained using the catalyst weight 3%, reaction temperature of 60 °C, reaction time of 3 h, mole ratio of oil/methanol 1:6 and the catalyst calcination time of 10 h with the conversion of 87.17%. This biodiesel yield by the two-step processes was higher (2.7%) than that using only one-step process (transesterification).

scholarly journals Aeration and Shear Stress Are Critical Process Parameters for the Production of Oncolytic Measles Virus

2019 ◽  
Vol 7 ◽  
Author(s):  
Tanja A. Grein ◽  
Daniel Loewe ◽  
Hauke Dieken ◽  
Tobias Weidner ◽  
Denise Salzig ◽  
...  
Keyword(s):  
Shear Stress ◽  
Process Parameters ◽  
Measles Virus ◽  
Critical Process Parameters ◽  
Critical Process

scholarly journals Semi-Synthetic Approach Leading to 8-Prenylnaringenin and 6-Prenylnaringenin: Optimization of the Microwave-Assisted Demethylation of Xanthohumol Using Design of Experiments

Molecules ◽  
2020 ◽  
Vol 25 (17) ◽  
pp. 4007
Author(s):  
Corinna Urmann ◽  
Herbert Riepl
Keyword(s):  
Reaction Time ◽  
Lithium Chloride ◽  
Biological Effects ◽  
Synthetic Approach ◽  
Prenylated Flavonoids ◽  
Microwave Assisted ◽  
Synthesis Strategy ◽  
Final Yield ◽  
Optimized Conditions ◽  
First Time

The isomers 8-prenylnaringenin and 6-prenylnaringenin, both secondary metabolites occurring in hops, show interesting biological effects, like estrogen-like, cytotoxic, or neuro regenerative activities. Accordingly, abundant sources for this special flavonoids are needed. Extraction is not recommended due to the very low amounts present in plants and different synthesis approaches are characterized by modest yields, multiple steps, the use of expensive chemicals, or an elaborate synthesis. An easy synthesis strategy is the demethylation of xanthohumol, which is available due to hop extraction industry, using lithium chloride and dimethylformamide, but byproducts and low yield did not make this feasible until now. In this study, the demethylation of xanthohumol to 8-prenylnaringenin and 6-prenylnaringenin is described the first time and this reaction was optimized using Design of Experiment and microwave irradiation. With the optimized conditions—temperature 198 °C, 55 eq. lithium chloride, and a reaction time of 9 min, a final yield of 76% of both prenylated flavonoids is reached.

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