Oxygen Polyacrylic acid

The dyes with long-lived luminescence are particularly attractive since background fluorescence can easily be discarded in time domain measurements. Crosssensitivity to oxygen may be problematic but it can be minimized by utilizing gas-blocking polymers. For example, Kuemer et al. [15] used the precipitation technique to prepare polyacrylonitrile-based beads doped with a ruthenium(II) complex which showed virtually no cross-sensitivity to oxygen. Copolymers of polyacrylonitrile and polyacrylic acid were used to provide the beads with... 

The second group already contains donor groups (usually oxygen or nitrogen) and, thus, requires no further chemical modification. These include polyacrylic acid (82, 83), polyvinyl alcohol (60), polymeric Schiff s bases (65), poly-L-methylethylenimine (52), poly-2-vinylpyridine (78, 79, 98), poly-4-vinylpyridine (24), and polyvinylamine (54, 59). 

The high-purity powder contains about 15 wt. % water and 0.05-0.1% carbon from the decomposition of polyacrylic acid used in the reduction autoclaves. Drying the copper powder in the presence of 2-3 wt. % oxygen is necessary to accelerate the removal of carbon during the sintering under an atmosphere of hydrogen. 

If the grafted chain is polyacrylic acid or polymethyl methacrylate, then we look for an increase in the percentage of oxygen as proof of grafting. 

Perfect transparency, is highly elastic, resistant to light, oxygen, diluted acids and alkalis. Does not withstand alkali attack under elevated temperatures (hydrolyzes till polyacrylic acid). Satisfactory mechanical resistance, low thermal resistance (70-80° C). 

Fig.5. Polarographic oxygen maximum suppression of polyacrylamide (curve 2) and polyacrylic acid (curve 3) in 10 M Na2S04-solution (curve 1). Polymer concentration 4 mg/1, drop time 2.8 s.

Use is being made of polymers alone in controlling deposits in boilers up to ISOOlb/in. The treatment solubilizes Ca "", Mg" " , Al" " " and maintains silica in solution. It removes scales from boilers. If polymers are to be used, oxygen must be strictly controlled. The effectiveness of a polymer is determined by its molecular weight and concentration. For example, polyacrylic acid (molecular weight = 20 000) addition reduces scale formation of only 52% compared to polymaleic acid (molecular weight = 5000) which reduces scale formation by 97%. Some typical polymers used are polycarboxylic acid, polymethacrylic acid, styrene and maleic add. 

The direct oxidation of propylene using air or oxygen produces acrolein. Acrolein may further he oxidized to acrylic acid, which is a monomer for polyacrylic resins. 

Effect of Anions in Copper Compounds. Since the copper stearate was the most effective catalyst among the transition metal stearates for the early stage of the thermal oxidation of polypropylene, the effect of anions in copper compounds on the thermal oxidation of atactic polypropylene was examined. The oxygen uptake curves of the polymer in the presence of various copper compounds (acetate, propionate, butylate, stearate, laurate, polyacrylate, and cupric oxide) are shown in Figure 4. In the absence of the copper compounds, oxygen uptake of the polymer increases linearly with time. In the presence of copper compounds of fatty acids (acetate, propionate, butyrate, laurate, and stearate), the oxygen uptake of the polymer levels off at ca. 25-30 O2 mL/g polymer after... 

Polyacrylate, a thermoplastic polymer, synthesized by polymerization of acrylate monomers, consists of acrylic acid (AA) esters shown in Figure 1 as the general stractirre. Methacrylate monomer differs from the acrylate monomer in that the H atom at the virtyl oxygen is substituted by a methyl group (-CH ). The wide variety of side chains and the variations in tactidty contribute to polyacry-... 

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