Explore chapters and articles related to this topic
Chemical Analysis
Published in Rudolf Puffr, Vladimír Kubánek, Lactam-Based Polyamides, 2019
Božena Lánská, Jaroslav Stehlíček
The original method suggested by Waltz and Taylor for the determination of the content of basic groups in polyamides consisted in the titration of a polymer dissolved in a mixture of phenol with methanol with 0.1 mol aqueous HCl using thymol blue.112,113 In this way, –COONa groups are also titrated in polyamides.123 The method is sometimes modified with respect to the solvent (cresol-methanol, acetic acid-benzene, benzyl alcohol-methanol-water, dimethylformamide), to the indicator (methyl orange, naphtyl blue, methyl violet, bromo-phenol blue, Phenolphthalein, thymolphthalein) or to the titrant (perchloric acid).115,120,127-130
Nonionic Polymers – The Acrylic Group
Published in Philip Molyneux, Water-Soluble Synthetic Polymers: Properties and Behavior, 1983
It is therefore more customary to assay PAA solutions via their carboxyl group content by titration with alkali (e.g., carbonate-free 0.05 M NaOH);1,17,30,56 sodium chloride (0.1 M) may be added to sharpen the end point,15,17,56 which can be detected either with indicators such as phenolphthalein17,56 or thymolphthalein,1 or by potentiometry.17,30,56
Application of dewatered paper sludge-derived porous solid base catalyst for biodiesel production: Physicochemical properties, reaction kinetics and thermodynamic studies
Published in Environmental Technology, 2022
Guoqiang Zhou, YuHan Liang, Zhirong Zheng, Lan Ju
The basic strength (H_) was detected and calculated using Hammett indicators [35]. During the experiment, the 800 mg sample was suspended in 2.5 mL Hammett indicators, which was diluted with 4.5 mL methanol beforehand. They were placed for 2.5 h to equilibrate until no more colour change happened. The following chemical reagents were employed as Hammett indicators: 4-nitroaniline (H_ = 18) 2, 4-dinitroaniline (H_ = 15), thymolviolet (H_ = 11.0), thymolphthalein (H_ = 10.0), phenolphthalein (H_ = 9.3) and neutral red (H_ = 6.8). To determine the basicity values (mmol/g) of dewatered paper sludge, dewatered paper sludge-derived catalyst, and CaO, the Hammett method utilized 0.01mol/L benzoic acid ethanol solution as an indicator and titrated until changed back to its original colour [36]. Besides, the basicity was also investigated with an AutoChem II 2920 (Micromeritics Ltd., USA) by the CO2-TPD analysis method.
Optimization and kinetic studies on biodiesel production from microalgae (Euglena sanguinea) using calcium methoxide as catalyst
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2019
Arun Prasad Arunachalam Sivagurulingam, Periyasamy Sivanandi, Sivakumar Pandian, Sakthi Saravanan Arumugamurthi, Anirbid Sircar
The basic strength of the catalyst was determined by Hammet indicators. The catalyst (300 mg) was mixed with 1 mL Hammett indicator and makeup to 20 mL with the gradual addition of anhydrous methanol. The color of the catalyst was noted after 2 h of equilibrium. The basic strength of the catalyst will be between the higher than the weakest indicator that undergoes colour change and lower than the strongest indicator that does not change the color. The indicators used for the experiment were bromothymol blue (H_ = 7.2), phenolphthalein (H_ = 9.3), thymolphthalein (H_ = 10.0), thymolviolet (H_ = 11.0) 2,4 dinitro aniline (H_ = 15) and 4-nitro aniline (H_ = 18.4). Similarly, the basicity of the catalyst was determined by titration method using Hammett indicator (benzene carboxylic acid and 0.02 mol L−1 anhydrous methanol). The surface properties of the catalyst were analyzed using Sorptomatic 1990 (Thermo Fisher Scientific, USA) to determine its total surface area, total pore volume, and the average pore size.
Effective difference volumes of inoculum for methane production in anaerobic batch digestion by using casein
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2018
Boualy Vongvisith, Wudi Zhang, Ming Liu, Xiyan Ji, Fang Yin, Changmei Wang, Kai Wu, Xingling Zhao, Jing Liu, Hong Yang
This experiment was conducted in duplicates for statistical significance of seven glass bottles (reactors) provided with the different volumes of control groups for 10%, 20%, 30% and 40%, respectively, that its without mixed casein to test the quality of the inoculum, and 7 of sample glass bottles (reactors) were also fed with activated sludge (inoculum) in the different volumes amount for 10%, 20%, 30% and 40%, respectively, by 10 g of casein added, which the details of duplicate samples and control groups are given in Table 1. The BMP system consists of 14 glass bottles of the volume 500 ml, with a working volume of 400 ml; the reactors were stirred in cycles of 60-s mixing and 60-s resting, and mixer speed adjusted for 80% at temperature condition at 30°C for 60 days of hydraulic retention time (HRT), in which the biogas produced passed through a CO2 capturing unit (consisting of a 3 mole of sodium hydroxide (NaOH) solution with 0.4% Thymolphthalein pH indicator), and the data were recorded by AMPTS II software and automatically transferred to an MS ExcelTM file for subsequent analysis and visualization (Bioprocess Control Sweden AB 2014., Badshah et al. 2012., Jonh 2011). The theoretical methane potential of the casein as substrate at standard temperature and pressure conditions was estimated through their elemental composition and the stoichimometry of the degradation reaction, which formula was CnHaObNc compound, using Buswell and Muller’s formula (Equation (1)) (Kim et al. 2014; Lim et al. 2013). Equation (1):