Pyrolysis of predried dyeing sludge: weight loss characteristics, surface morphology, functional groups and kinetic analysis

Author(s):  
Bo Wang ◽  
Xiang Xu ◽  
Xiu Cao ◽  
Yinhe Liu
Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2923
Author(s):  
Baneen Salam ◽  
Gamal A. El-Hiti ◽  
Muna Bufaroosha ◽  
Dina S. Ahmed ◽  
Ahmed Ahmed ◽  
...  

The lifetime of poly(vinyl chloride) (PVC) can be increased through the addition of additives to provide protection against irradiation. Therefore, several new tin complexes containing atenolol moieties were synthesized and their photostabilizing effect on PVC was investigated. Reacting atenolol with a number of tin reagents in boiling methanol provided high yields of tin complexes. PVC was then mixed with the tin complexes at a low concentration, producing polymeric thins films. The films were irradiated with ultraviolet light and the resulting damage was assessed using different analytical and surface morphology techniques. Infrared spectroscopy and weight loss determination indicated that the films incorporating tin complexes incurred less damage and less surface changes compared to the blank film. In particular, the triphenyltin complex was very effective in enhancing the photostability of PVC, and this is due to its high aromaticity (three phenyl rings) compared to other complexes. Such an additive acts as a hydrogen chloride scavenger, radical absorber, and hydroperoxide decomposer.


2021 ◽  
Vol 2080 (1) ◽  
pp. 012024
Author(s):  
Wan Mohd Haqqi Wan Ahmad ◽  
Siti Hawa Mohamed Salleh ◽  
Shaiful Rizam Shamsudin ◽  
Rajaselan wardan ◽  
Mohd Subhi Din Yati ◽  
...  

Abstract A Capacitive Coupling Corrosion Protection (CCCP) technology based on coupler pads was investigated. The layout of the coupler pads on the mild steel surface was studied to get the best outdoor corrosion protection. A square wave of current/voltage is supplied to the steel surface for 72 hours via a copper coupler pad in three arrangements, i.e., single, double-sided, and opposite configurations. The efficiency of the CCCP configuration was assessed by measuring electrical current consumption, weight loss, and post-experimental surface morphology observations. It is found that the current consumption of 600 μA/cm2 in the double-sided configuration is practically stable. The lowest weight loss and clean surface morphology also prove that the double-sided configuration can improve the corrosion protection of mild steel. It was discovered that by employing more coupling pads on both sides of the metal sheet, the excessive positive charge capable of producing oxidation of mild steel could be easily discharged.


Author(s):  
Juan A. Conesa

Research abounds in the literature on kinetic analyses using thermogravimetric (TG) runs. Many of these studies use approximations of integral or derivative forms of the kinetic law and all of them use programmed temperature, not the actual temperature measured by thermocouples close to the sample. In addition, it is common to conduct a single run in order to perform the calculation. Nevertheless, many authors consider that numerical methods should be used to analyse the kinetics of decomposition. In such cases, the actual temperature is used and, generally, several runs are fitted using the same kinetic parameters, giving robustness to the results. In the present work, a numerical integration procedure was discussed and applied to different examples. We focused on materials presenting a single decomposition curve as well as other materials with more complex processes. Different examples were explored, and the methodology was applied to a number of wastes such as coffee husks, polystyrene and polyethylene.


Polymers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1185 ◽  
Author(s):  
Emad Yousif ◽  
Dina Ahmed ◽  
Gamal El-Hiti ◽  
Mohammad Alotaibi ◽  
Hassan Hashim ◽  
...  

Polystyrene films containing a low concentration of three highly aromatic Schiff bases were prepared using the casting method. The polystyrene films were irradiated with ultraviolet light (300 h). The polystyrene infrared spectra, weight loss, molecular weight reduction and the surface morphology were examined upon irradiation. The Schiff bases acted as photostabilizers and reduced the photodegradation of polystyrene films to a significant level in comparison to the blank film. The images recorded of the surface of the miscible polystyrene/Schiff base blends showed novel ball-like microspheres with a diameter of 3.4–4.3 µm. The Schiff bases were able to endow excellent protection to polystyrene against ultraviolet irradiation.


2017 ◽  
Vol 19 (1) ◽  
pp. 120-126 ◽  
Author(s):  
Aleksandra Heimowska ◽  
Magda Morawska ◽  
Anita Bocho-Janiszewska

AbstractThe environmental degradation of poly(ε-caprolactone)[PCL] in natural fresh water (pond) and in The Baltic Sea is presented in this paper. The characteristic parameters of both environments were measured during experiment and their influence on the biodegradation of the samples was discussed. The loss of weight and changes of surface morphology of polymer samples were tested during the period of incubation. The poly(ε-caprolactone) was more biodegradable in natural sea water than in pond. PCL samples were completely assimilated over the period of six weeks incubation in The Baltic Sea water, but after forty two weeks incubation in natural fresh water the polymer weight loss was about 39%. The results have confirmed that the investigated polymers are susceptible to an enzymatic attack of microorganisms, but their activity depends on environments.


2012 ◽  
Vol 441 ◽  
pp. 360-365 ◽  
Author(s):  
Qian Jie Zhang ◽  
Ke Lu Yan

In this paper, a shrinkproofing treatment of wool fabrics was carried out by excilamp combined with enzyme. Shrinkproofing properties of the treated fabrics were evaluated by measuring the values of directional friction effect (DFE), felting shrinkage and weight loss. The results showed that felting shrinkage of the treated wool fabrics could achieve the machine washability standard (ISO 6330 and IWS TM 31) with low fiber damage. Surface morphology and chemical composition of the treated fabrics were observed and analyzed by SEM and FTIR-ATR. This treatment was compared with low-temperature oxidation combined with enzyme method (ARS Process).


Thermo ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 32-44
Author(s):  
Juan A. Conesa

Research abounds in the literature on kinetic analyses using thermogravimetric (TG) runs. Many of these studies use approximations of integral or derivative forms of the kinetic law and all of them use programmed temperatures. In the present work, a numerical integration procedure was discussed and applied to different examples. We focused on materials presenting a single decomposition curve as well as other materials with more complex processes. Different examples were explored, and the methodology was applied to a number of wastes such as coffee husks, polystyrene and polyethylene. In all cases, the actual temperature measured by thermocouples close to the sample is used, and several runs are fitted using the same kinetic parameters, giving robustness to the results.


2017 ◽  
Vol 4 (2) ◽  
pp. 186-194 ◽  
Author(s):  
Tan I. A. W. ◽  
Abdullah M. O. ◽  
Lim L. L. P. ◽  
Yeo T. H. C.

Activated carbon derived from agricultural biomass has been increasingly recognized as a multifunctional material for various applications according to its physicochemical characteristics. The application of activated carbon in adsorption process mainly depends on the surface chemistry and pore structure which is greatly influenced by the treatment method. This study aims to compare the textural characteristics, surface chemistry and surface morphology of coconut shell-based activated carbon modified using chemical surface treatments with hydrochloric acid (HCl) and sodium hydroxide (NaOH). The untreated and treated activated carbons were characterized for their physical and chemical properties including the Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and textural characterization. The FTIR spectra displayed bands confirming the presence of carboxyl, hydroxyl and carbonyl functional groups. The Brunauer–Emmett–Teller (BET) surface area of the untreated activated carbon was 436 m2/g whereas the surface area of the activated carbon modified using 1M NaOH, 1M HCl and 2M HCl was 346, 525 and 372 m2/g, respectively. SEM micrographs showed that many large pores in a honeycomb shape were clearly found on the surface of 1M HCl sample. The pore structure of the activated carbon treated with 2M HCl and NaOH was partially destroyed or enlarged, which decreased the BET surface area. The modification of the coconut shell-based activated carbon with acidic and alkaline treatments has successfully altered the surface functional groups, surface morphology and textural properties of the activated carbon which could improve its adsorptive selectivity on a certain adsorbate.


Sign in / Sign up

Export Citation Format

Share Document