Intrinsic viscosity, hydrolyzed

The significance of knowing the K and a values of fully hydrolyzed PVA is that molecular weight distribution data can be directly calculated using two methodologies. The first is the Mark-Houwink method, which requires prior knowledge of K and a values for fully hydrolyzed PVA and calibration standards such as PEG, PEO, or PSC. The second method is the intrinsic viscosity method. This method utilizes a simple ratio of the concentration signal to the specific... 

Weight BTEMB (g) Weight Percent of NaOH Volume of NaOH (mL) Weight Percent of Fibers Hydrolyzed Weight of Oligomers Formed (g) Intrinsic Viscosity (dl/g) My (g/mol)... 

Kowblansky et A1 (19) have also measured the intrinsic viscosity of hydrolyzed polyacrylamide of a given molecular weight as a function of r for a - 1 and their results can be fitted by the expression ... 

Comparison of the limiting viscosity numbers determined in deionized water with those determined in 1 molar sodium nitrate shows a 20 per cent decrease in copolymer intrinsic viscosity in the saline solution. These results are consistent with previous studies using aqueous saline solutions as theta solvents for 2-propenamide polymers(47) Degree of hydrolysis controls the value of limiting viscosity number for the hydrolyzed copolymers in distilled water. 

Materials Used, The poly(vinyl alcohol) used in this study was a commercial (Borden chemical) grade of fully hydrolyzed material which had an aqueous intrinsic viscosity of 0,762 which corresponds to a molecular weight of about 59,900. This material was dried in a vacuum oven for several days at about 100°C and 10 torr before it was used in the modification experiments. Dry, analytical grade dimethyl sulfoxide (DMSO) was used as supplied. 

Polymer solution viscosity is a troubleshooting tool for polymer processing. Solution viscosity may be utilized to determine the degradation of some polymers via a decrease in molecular weight, particularly for polymers that can be hydrolyzed by water. It can be a troubleshooting tool because the results can be obtained quite rapidly. Intrinsic viscosity is commonly known as IV when referring to polyesters. It is applicable, however, to any polymer that is soluble at moderate concentrations in a good solvent [2]. 

Materials. Two samples of polyacrylic acid, PAA-1 (4) and PAA-2, were obtained as gifts from S. C. Johnson Company. Their degrees of polymerization were 3090 and 4420, respectively, as calculated from the intrinsic viscosities of their sodium salts in 0.102V NaBr at 15°C using the appropriate relation of Takahashi and Nagasawa (5). The samples of the hydrolyzed copolymers of maleic anhydride witn ethylene (HEMA) and with methyl vinyl ether (HVMEMA) have been described previously (4). 

Figure 2. Log-log plot of intrinsic viscosity va. M for hydrolyzed levan fractions...

Fig. 13.12 Normalized intrinsic viscosity of PBT granules hydrolyzed vs time.

Table 5 Weight-Average Molecular Weight () and Intrinsic Viscosity of PAM and 25% Hydrolyzed PAM...

Two mobile-phase compositions of H O/CHjCN (80 20, vol/vol) and 0.10 MNaNOj/CHjCN (80 20, vol/vol) were used for SEC-viscometry of partially hydrolyzed grades (32). PEO, PEG, and PSC were used for column calibration, and universal calibration was observed (29). Molecular weights by SEC-viscometry for grades of high, medium, low, and superlow molecular weight compare favorably those from SEC-LALLS, especially with the H O/CHjCN mobile phase (Table 6). It is suspected that the nonsalt mobile phase works better to eliminate the hydrophobic interactions and maximize the size exclusion mechanism (32). Intrinsic viscosity values calculated from viscometry for the two acetonitrile mobile-phase compositions and from Ubbelohde viscometry in HjO/CH CN, are also summarized in Table 6. 

Intrinsic Viscosity as a Function of (solution ionic strength)for sodium chloride solutions of various hydrolyzed poly(1-amidoethylenes) [A,B,C,] and poly (l-(N,N-dimethylamido) ethylene-co-l-amidoethylene), (11). (T 30 C). Poly(l-(N,N-dimethylamido)-... 

Fig. 5. Intrinsic viscosity of partially hydrolyzed polyacrylamides in 1.5% NaCl solution.

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