Co(III) complex mediated microwave‐assisted synthesis of PAN

Abstract

Free radical polymerization of acrylonitrile (AN) is efficiently, easily, and quickly achieved in the presence of Co(III) complex, [Co(III) en 3 ]Cl 3 and ammonium persulphate (APS) in domestic microwave oven. The rate of polymerization depends on the power and time of microwave irradiation, and is independent of the technique employed (periodic or continuous irradiation). The conversion of monomer to the polymer was mostly excellent in gram scale. Irradiation at low power and time produced more homogeneous polymers with high molecular weight and low polydispersity when compared with the polymer formed by conventional heating method. The interaction of reacting components was monitored by UVvisible spectrometer. The average molecular weight was derived by GPC and viscosity methods and sound velocity by ultrasonic interferometer. The uniform and reduced molecular size was characterized by transmission electron microscopy, the diameter of PAN particles being in the range 220-250 nm in microwave and 120-530 nm in conventional heating methods. From the kinetic results, the rate of polymerization (R p ) was expressed as R p ¼ K½CoðIIIÞ 0:33 ½APS 0:31 ½AN 0:88

Microwave‐assisted chemical synthesis of conducting polyindole: Study of electrical property using Schottky junction

“…As illustrated from chromatographic results, M n of dominant fraction is located around 950 and 1500 for PIn synthesized conventionally using APS and KIO 3 , respectively [as shown in Figure 5(a,b)], while 1450 and 1550 for PIn synthesized by APS and KIO 3 via microwave radiation, respectively [as shown in Figure 5(c,d)]. Sharp peaks are observed for PIn obtained using oxidizing agent KIO 3 indicating a narrow distribution of M n while the minuscule humps present for PIn obtained using oxidizing agent APS (as shown in inset of Figure 5) are due to fragmentation of polymeric chains and traces of lower molecular weight polymeric fragments (i.e.…”

“…This is due to wide range molecular weight distribution of PIn synthesized by APS in which the longer polymeric chains may be grasped together by smaller chains. That is why PIn synthesized by APS shows degradation of about 67% at 600 C whereas PIn synthesized by KIO 3 shows same degradation at 340 C. Thermal behavior of PIns is also analyzed by DTA (as is shown in Supporting Information Figure S1). From this study we observed that degradation of PIns is exothermic in nature from 100 C to 600 C.…”

“…1,2 It is reported that microwave involves dielectric heating which couples directly with the microwave absorbing polar solvent molecules that are present in the reaction mixture and transfer energy selectively leading to a fast rise in temperature, rapid reactions, cleaner chemistry, and nucleation of the polymeric material. 3 There are two fundamental mechanisms, dipole rotation and ionic conduction, that are reported for the transfer of energy from microwaves to the substance. Thus, it can facilitate mass production in a very short time frame with little energy cost and forms an intimate contact between reacting species which is crucial for the formation of electronic interactions and interelectron transfer at the interface.…”

Endothelial cell response to (co)polymer nanoparticles depending on the inflammatory environment and comonomer ratio

“…In order to systematically study the interaction of P(AN-co-NVP)-based nanoparticles with ECs, monomodal, narrow particle size distributions were envisioned, which ideally should be formed by combining copolymer synthesis and particle formation in an integrated process. The synthesis of AN-based nanoparticles has been systematically studied, mostly based on (macro)emulsion/dispersion polymerization [18][19][20], which in some cases involved the use of solvents or metal based catalysts with assumed toxicity and/or may result in particles with a larger size distribution. Several of these challenges can be overcome by acrylonitrile copolymerization in miniemulsions [21], in which less surfactant is required when compared to the high detergent levels used for polyacrylonitrile nanoparticle synthesis in microemulsions [22] and a hydrophobic costabilizer impedes Ostwald ripening of nascent droplets/particles, thereby enabling narrow size distributions.…”

Green Polymer Synthesis: An Overview on Use of Microwave‐Irradiation

“…Free radical polymerization of acrylonitrile (AN) is efficiently, easily, and quickly achieved in the presence of Co(III) complex, [Co(III) en 3 ]Cl 3 and ammonium persulphate (APS) in domestic microwave ovens. Irradiation at low power and time produced more homogeneous polymers with high molecular weight and low polydispersity in comparison to the polymer formed by conventional heating method [52].…”