Chemical Modification of Polystyrene Merrifield: Extraction of Zinc and Magnesium Located in Wastewater
Abid Ouerghui,
Mokhtar Dardouri,
Hichem Elamari,
Faycel Ammari,
Christian Girard
Issue:
Volume 5, Issue 3, September 2019
Pages:
73-80
Received:
26 June 2019
Accepted:
19 July 2019
Published:
6 August 2019
Abstract: In order to remove metals (Zn & Mg) located in wastewater, a new series of clickable polystyrene Merrifield grafted with azide and alkynes were synthesized and implicated in this domain. In a first step, we transformed the polystyrene Merrifield into the known Azidomethyl polystyrene, in a second step, a coupling reaction between the Azidomethyl polystyrene and dipropargylamine was realized for the synthesis of a new terminated polystyrene alkyne containing one unit of (1,4)-triazole. To increase the length of the chain grafted on the polystyrene Merrifield, several coupling reactions are applied, the main idea of this work was to increase the number of (1,2,3) –triazole units of this grafted chain. The click chemistry based on the Huygens’s reaction catalyzed by copper (I) was used in this synthesis, the new polymers containing (1,4)-disubstituted triazole are tested for the extraction of Mg and Zn located in wastewater. The structure of new obtained polymers was confirmed by infrared spectroscopy (ATR-FTIR), UV-visible spectroscopy and elemental analysis for nitrogen. Differential Thermal Analysis (DTA) and Thermo Gravimetric Analysis (TGA) were used to study crosslinking behavior of these polymers. This study shows a low selectivity of studied polymers for the retention of magnesium, while for the Zinc, the percentage removal was average, it’s in the order of 30%.
Abstract: In order to remove metals (Zn & Mg) located in wastewater, a new series of clickable polystyrene Merrifield grafted with azide and alkynes were synthesized and implicated in this domain. In a first step, we transformed the polystyrene Merrifield into the known Azidomethyl polystyrene, in a second step, a coupling reaction between the Azidomethyl po...
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Promising Polymer Composites for Food Packaging Applications
Issue:
Volume 5, Issue 3, September 2019
Pages:
81-87
Received:
30 June 2019
Accepted:
23 July 2019
Published:
13 August 2019
Abstract: Blending starches with biodegradable polycaprolactone (PCL) was used as a route to make processable thermoplastics. When developing biodegradable polymer composites it is important to use high concentrations of starch for legislative and cost reasons. The addition of starch has a significant effect on all physical properties including toughness, elongation at break and the rheological behaviour of the melt. To enhance the physical properties, we used cellulose acetate propionate (CAP) as a cellulose derivative with high amylase starch and PCL blends. It is suggested that the PCL/starch/CAP blends are partially miscible. It was found that the yield tensile strengths of most PCL/Starch/CAP blends were higher than that of pure PCL itself. There was a big difference between glass transition temperature values of PCL/Starch/CAP blends and the pure PCL glass transition temperature which indicates that no phase separation occurs. Addition of CAP to starch and PCL blends improved the mechanical and thermal properties even at high content of starch.
Abstract: Blending starches with biodegradable polycaprolactone (PCL) was used as a route to make processable thermoplastics. When developing biodegradable polymer composites it is important to use high concentrations of starch for legislative and cost reasons. The addition of starch has a significant effect on all physical properties including toughness, el...
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Solvent Decomposition of Polyurethane Foam Obtained from Waste Upholstered Furniture to Recover Polyols
Yanfang Pang,
Xiaosheng Liu,
Yan Li,
Tongtong Cui,
Xin Liu,
Qi Li,
Hui Wan,
An Mao
Issue:
Volume 5, Issue 3, September 2019
Pages:
88-96
Received:
11 July 2019
Accepted:
4 August 2019
Published:
15 August 2019
Abstract: The objective of this study was to investigate the feasibility of recovering the polyols from the polyurethane (PU) foam obtained from waste upholstered furniture (sofa) by chemical decomposition using the propylene glycol (PPG) as the decomposing solvent and sodium hydroxide (NaOH) as the catalyst, respectively. The effects of temperature (180°C and 200°C), reaction time (0.5, 1, 1.5, 2, 2.5, and 3 hours), and PPG/PU weight ratio (2:1, 3:1, and 4:1) on the decomposition reaction and the physicochemical properties of the recovered polyols, such as hydroxyl number, viscosity, and amine number were investigated. Higher temperature and PPG/PU weight ratio promoted the PU decomposition reaction and resulted in lower viscosity, higher hydroxyl number, and higher amine number of the recovered polyols. The hydroxyl number and amine number increased as the reaction progressed, while the viscosity decreased. Once the reaction was completed, little change was observed for the hydroxyl number and viscosity of the recovered polyols. The recovered polyol obtained at 200°Cand PPG/PU weight ratio of 3:1 showed about the same length of time for the reaction, as well as the physical properties to that obtained at 180°C and PPG/PU weight ratio of 4:1. These recovered polyols had similar hydroxyl number and viscosity to those of commercial polyol used for PU coatings, elastomers, adhesives, and sealants.
Abstract: The objective of this study was to investigate the feasibility of recovering the polyols from the polyurethane (PU) foam obtained from waste upholstered furniture (sofa) by chemical decomposition using the propylene glycol (PPG) as the decomposing solvent and sodium hydroxide (NaOH) as the catalyst, respectively. The effects of temperature (180°C a...
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