A Water-Soluble and Self-Doped Conducting Polypyrrole Graft Copolymer

2005 ◽  
Vol 38 (4) ◽  
pp. 1044-1047 ◽  
Author(s):  
Woo Jin Bae ◽  
Keon Hyeong Kim ◽  
Won Ho Jo ◽  
Yun Heum Park
2010 ◽  
Vol 14 (02) ◽  
pp. 128-132 ◽  
Author(s):  
Mohammad Reza Nabid ◽  
Mitra Shamsianpour ◽  
Roya Sedghi ◽  
Samira Osati ◽  
Nasser Safari

A novel catalytic route for the synthesis of a water-soluble and electrically conducting polypyrrole (PPy) in the presence of sulfonated polystyrene (SPS) is presented. Anionic water-soluble transition-metal tetrasulfonated porphyrins (TSPP) were used to catalyze the polymerization. The reactions were carried out with different monomer, catalyst, template and initiator concentrations and the optimum conditions are reported. Also various pH values ranging from 1 to 4 were investigated. The absorbance of the polaron bands at different pH values demonstrates that pH 2 is the best condition for polymerization. Precipitation or "salting out" phenomenon was highly dependent on the mentioned factors. The formation of PPy was confirmed by UV-vis and FT-IR spectroscopy. Cyclic voltammetry (CV) showed that the synthesized polymer has convenient electroactivity. Furthermore, the presence of SPS that serves as a charge-compensating dopant in this complex provides a unique combination of properties such as processability and water solubility.


2013 ◽  
Vol 781-784 ◽  
pp. 554-559 ◽  
Author(s):  
Yu Meng Zheng ◽  
Xiao Ran Sun ◽  
Guang Yue Li

A water-soluble graft copolymer, which was used to improve the dispersion properties of kaolin slurry with high solid content , was synthesized from sodium humate (HA), acrylic acid (AA), starch (St) and potassium persulfate (KPS) by aqueous solution polymerization. The influence of raw material ratio, dosage of initiator, temperature and reaction time to poly-dispersant properties, which was measured by kaolin slurry viscosity, was studied in detail. It was observed that poly-dispersant prepared in this study exhibited good dispersion properties for kaolin slurry. This is most probably due to high electrostatic repulsion force and steric stability between kaolin particles, which is fully covered by poly-dispersant with suitable molecular weight, molecules contain appropriate side chains and charge density. The optimum conditions are as follows: the mass ratio of St/(AA&HA) is 1:30, the mass ratio of HA/AA is 3:1, and the reaction temperature is 70°C, the dosage of KPS is 7%, reaction time is 2h. It was also observed that viscosity of kaolin slurry was strongly affected by concentrations of Poly(Starch-Acrylic acid-Sodium humate) (P(St-AA-HA)). The optimal content of the poly-dispersant is 0.5%. Fourier transform infrared (FTIR) proved that the product was a graft copolymer of St-AA-HA.


2021 ◽  
Author(s):  
Xavier Castellvi Corrons ◽  
Jeremie Gummel ◽  
Johan Smets ◽  
Debora Berti

The liquid-liquid phase separation (LLPS) of amphiphilic thermoresponsive copolymers can lead to the formation of micron-sized domains, known as simple coacervates. Due to their potential to confine active principles, these copolymer-rich droplets have gained interest as encapsulating agents. Understanding and controlling the conditions inducing this LLPS is therefore essential for applicative purposes and requires thorough fundamental studies on self-coacervation. In this work, we investigate the LLPS of a comb-like graft copolymer (PEG-g-PVAc) consisting of a poly(ethylene glycol) backbone (6 kDa) with 2-3 grafted poly(vinyl acetate) chains, and a PEG/PVAc weight ratio of 40/60. Specifically, we report the effect of various water-soluble additives on its phase separation behavior. Kosmotropes and non-ionic surfactants were found to decrease the phase separation temperature of the copolymer, while chaotropes and, above all, ionic surfactants increased it. We then focus on the phase behavior of PEG-g-PVAc in the presence of sodium citrate and a C14-15 E7 non-ionic surfactant (N45-7), defining the compositional range for the generation of LLPS microdomains at room temperature and monitoring their formation with fluorescence confocal microscopy. Finally, we determine the composition of the microdomains through confocal Raman microscopy, demonstrating the presence of PEG-g-PVAc, N45-7, and water. These results expand our knowledge on polymeric self-coacervation, clarifying the optimal conditions and composition needed to obtain LLPS microdomains with encapsulation potential at room temperature in surfactant-rich formulations.


2010 ◽  
Vol 80 (4) ◽  
pp. 1102-1110 ◽  
Author(s):  
Mohamad Nasir Mohamad Ibrahim ◽  
Mohamed Rashid Ahmed-Haras ◽  
Coswald Stephen Sipaut ◽  
Hassan Y. Aboul-Enein ◽  
Abdullahi Ali Mohamed

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