A new photopolymerization system for vinyl monomers

Abstract

A mixture of Ce ϩ3 salt and an aminomethylene phosphonic acid, such as amino tri(methylene phosphonic acid) (ATMP), diethylene triamine penta(methylene phosphonic acid), N,N-di(methylene phosphonic acid) ethanol amine, N,N-di(methylene phosphonic acid)-N-methylamine, N-oxo-N,N,N-tri(methylene phosphonic acid), or 1-hydroxy-ethylidene-1,1-diphosphonic acid, was used for the photopolymerization of acrylonitrile, vinyl acetate, acrylic acid, and styrene in water. Molecular weights of the polymers decreased with increasing concentration of both Ce ϩ3 salt and ATMP. The effect of oxygen, light, pH, and the addition order on polymerization were also studied.

Block copolymers of N‐vinyl carbazole and α,ω‐dihydroxy polydimethylsiloxane

“…We produced PNVCz ‐b‐ DH.PDMS copolymers in one step at room temperature in 1 h by the polymerization of NVCz monomer with the redox initiation system of Ce 4+ and DH.PDMS. The polymerization probably proceeds with a mechanism similar to the redox systems of Ce 4+ /DH.PDMS and Ce 4+ /polyethylene glycol as proposed earlier 5, 14. The redox reaction between Ce 4+ and the hydroxyl group of DH.PDMS produces a radical that initiates the polymerization of NVCz (Scheme ) to form PNVCz ‐b‐ DH.PDMS copolymers.…”

“…Recently, we have started to use the redox system of Ce 4+ and hydroxyl containing compounds such as α,ω‐dihydroxy polydimethylsiloxane (DH.PDMS), α,ω‐diamino polydimethylsiloxane (DA.PDMS) and ketonic resins to polymerize N ‐vinyl carbazole (NVCz), styrene (ST), acrylonitrile (AN), and pyrrole (Py). The resulting products were the copolymers of polystyrene ‐b‐ α,ω‐dihydroxy polydimethylsiloxane (PS ‐b‐ DH.PDMS),5 polyacrylonitrile ‐b‐ α,ω‐dihydroxy polydimethylsiloxane (PAN ‐b‐ DH.PDMS),5 polypyrrole ‐b‐ α,ω‐dihydroxy polydimethylsiloxane (PPy ‐b‐ DH.PDMS),6 high conductive polypyrrole ‐b‐ α,ω‐diamino polydimethylsiloxane (DA.PDMS),7 and PNVCz‐ketonic resins8 respectively. These copolymers have better solubility,6 higher conductivity,6, 7 and higher contact angle values 5, 6.…”

“…The resulting products were the copolymers of polystyrene ‐b‐ α,ω‐dihydroxy polydimethylsiloxane (PS ‐b‐ DH.PDMS),5 polyacrylonitrile ‐b‐ α,ω‐dihydroxy polydimethylsiloxane (PAN ‐b‐ DH.PDMS),5 polypyrrole ‐b‐ α,ω‐dihydroxy polydimethylsiloxane (PPy ‐b‐ DH.PDMS),6 high conductive polypyrrole ‐b‐ α,ω‐diamino polydimethylsiloxane (DA.PDMS),7 and PNVCz‐ketonic resins8 respectively. These copolymers have better solubility,6 higher conductivity,6, 7 and higher contact angle values 5, 6. Besides, the electroinduced oxidative copolymerization of NVCz with methyl ethyl ketone‐formaldehyde resin was studied and the copolymerization yield was found to be almost 10 times higher than the yield obtained by the redox polymerization method for the same Ce 4+ concentration 8.…”

Ethoxylated nonyl phenols and ethoxylated fatty alcohols–ceric ion redox systems for aqueous polymerization of vinyl monomers

“…Increasing the Ce +4 concentration above this value resulted in the yield of polymerization to become inversely proportional to Ce +4 concentration, probably because of linear termination by Ce +4 . Besides, increasing Ce +4 concentration is known to cause a significant increase in the rate of oxidative termination of primary radicals compared with the rate of initiation 16. Oxidative chain termination and linear termination by Ce +4 ions probably was significant at higher Ce +4 concentration (>5.7 mmol · L −1 ) so both the molecular weight and the polymerization yield became inversely proportional to the Ce +4 concentration.…”

“…Organic reducing compounds7 including glucose,8 maltose,9 carboxylic acid,10 hydroxy acid,11 amino acid,12 ethylenediamine tetraacetic acid,13, 14 nitrilotriacetic acid,15 nitrilotripropionic acid,15 iminodiacetic acid,15 amino tri(methylene phosphonic acid),16 diethylene triamine penta(methylene phosphonic acid),16 and 1‐hydroxy‐ethylidene‐1,1‐diphosphonic acid 16 were used as reducing agent for redox polymerization of vinyl monomers. The polymers produced by Ce +4 /organic reducing compounds were suggested to have chain ends of the corresponding reducing compound moiety 16…”