Measurement units poly water

The weight fi actions of the sorbed water were 4.7, 3.1, 2.3, 0.3, and 0.1wt% for PMANKA), PMANKB), PMANI(0, PPRNI(B), and PBZNI(B), respectively, at 95% relative humidity. For the PMANI series of polymers, a plot of weight fraction of water sorbed vs. mole firaction of NISS gave a linear line. The value extrapolated to 0% of NISS fraction was 1.1% which was in good agreement with the value (1.05%) measured for poly(methyl methacrylate). The introduction of NISS units into the polymers enhanced their water sorption ability. The more hydrophobic nature of the methacrylate ester groups decreased the water sorption abflity. 

Figure 3 Reversed-phase chromatography of products after alkaline hydrolysis of /3-poly(L-malate), Discrete polymer products are formed, which differ in length by several units of L-malate. The absorbance at 220-nm wavelength was measured, (a) /3-Poly(L-malate) before hydrolysis, (b) After 10-min incubation in 20 mM NaOH at 37°C. (c) After 15 h in 20 mM NaOH at 37°C. (d) After I h in 500 mM NaOH at 100°C. High pressure chromatography (HPLC) on Waters reversed-phase Ci8- i-Bondapak. The methanol gradient (in water-trifluoro acetic acid, pH 3.0) was programmed as follows 0-40 min 0.3-23%, 40-47 min 23-40%, 47-49 min 40%, 49-54 min 40-0%. (d) Inset size exclusion chromatography after 3-min alkaline hydrolysis at pH 10.2. BioSil SEC 250 column of 300 mm x 7.8 mm size, 0.2 M potassium phosphate buffer pH 7.0.

Upadhyay et al. [98] used primarily correlated XPS and water contact angle measurements to study the surface degradation and recovery of amorphous films of a PMMA and a poly (aryl ether ether ketone) (PEEK). Surface modification of the films was carried out in a dielectric barrier discharge (DBD) unit, samples being treated with different dose levels of dielectric discharge. The modified (treated) samples were then stored for one month and re-examined. Figure 35 shows C(ls) and 0(1 s) XPS envelopes and their curve-fitting deconvolutions,... 

Figure 17 shows the chemical structures of anionic amphiphile sodium-1,2-bis (tetradecylcarbonyl)ethane-l-sulfonate (2Cj4SNa)[34] and poly(ethyleneimine)(PEI). A benzene/ethanol (9 1)(WV) solution of anionic amphiphile was spread on the pure water surface or the PEI-water solution (lxlO5 unit M in monomer unit, pH=3.2) surface at a subphase temperature, Tsp of 293 K. At this pH, ca. 70 % of nitrogen atom in PEI molecule was protonated[35]. Surface pressure-area(ji-A) isotherms were measured with a microprocessor controlled film balance system. 

Surface pressure [68] (it) vs. Area (A) (A2 per repeating unit) isotherms were measured for MA-alt-StM on water and on aqueous poly (monomethyl itaconate) solutions at pH 3.0 and 7.0. Figure 3.12 shows these isotherms. 

From the particle size measurements it was found that, in the case of carboxyl-functionalized samples stabilized with SDS, the particle size is relatively constant (around 100 nm) until 10 wt% of added acrylic acid. At higher amounts of acrylic acid, the diameter sharply increased, reaching an average value of 140 nm. The increase in particle size with increased amount of acrylic acid was explained by the formation of a hairy layer around the particle, which is mainly composed of the hydrophilic poly(acrylic acid) units. In contrast, the size of the amino-functionalized particles is not strongly dependent on the initial amount of functional monomer and was in the range 110-130 nm. This was expected because, in contrast to acrylic acid, the AEMH (p/ftt = 8.5) is completely water-soluble at the experimental pH below 3.5. Moreover, AEMH is very reactive and shows strong chain-transfer behavior [72, 73], and therefore the surface layer mainly consists of short chains. 

Heux et al. (2000) found that after partial deacetylation (<50%), the product of chitin becomes soluble in acidified water. Therefore, chitosan is characterized by its DA, which is the average mole fraction/percentage of A-acetyl-D-glucosaminc units within the macromolecular chain (Desbrieres, 2002). Alternatively, Heux et al. (2000) calculated DA by measuring all carbonyl or methyl groups divided by the integral of all the carbon atoms in the backbones. The DD may be determined by a titration method in which chitosan is dissolved in 0.1% acetic acid to form a 0.01% solution. This is followed by titration with 0.0025 N poly (vinyl sulfate) potassium salt (PVSK) with 1% toluidine blue (TBO) as an indicator. The acetyl content of... 

Poly(diallyldimethylammonium chloride) was the first quaternary ammonium polymer approved for potable water clarification by the United States Public Health Service, and has historically been the most widely produced cationic polyelectrolyte. There have been several studies on the kinetics (26-37) and uses of diallyldimethylammonium chloride (DADMAC) (38-45) however, there have been no investigations in inverse microsuspension, the most common industrial method of polymerization. Furthermore, there is considerable disagreement between published reactivity ratios, probably because no satisfactory analytical methods have been described in the literature for residual monomer concentration or copolymer composition. For other commercially important quaternary ammonium polymers, such as dimethylaminoethyl methacrylate and dimethylaminoethyl acrylate, few kinetic data are available (46-51) only Tanaka (37) measured the reactivity ratios. 

The desorption forces of a linear segmented poly(A -isopropylacryamide-seg-styrene) copolymer on polystyrene (PS) surfaces were measured in aqueous media by SMFS. Owing to the hydrophobic nature of the PS segments and the similarity with the PS surface, the polymer forms a looplike structure at the PS/water interface. Thus, the interaction via hydrophobic interactions is determined in the unit of each PS segment. The most probable desorption force observed was 41 pN, corresponding to a desorption work of 49 kJ mol . ... 

Polyi v mylether)s °- o3-r 33 X Polyether is a polymer with oxygen atoms in the main or side chtiin. Among them, thermoresponsive poly(vinylether)s have oxymethylene and/or oxyethylene pendants in their side chains [30, 124,404-406] Phase separation temperature of vinyl ethers can be controlled by varying the number of the pendant oxyethylene units and/or the hydrophobicity of an co-alkyl group, R Tcp measurements typically reveal an abrupt reversible transition within AT = 1°C no hysteresis Homopolymers of ethyl vinylether and higher alkyl vinylethers are insoluble in water... 

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