1990 Fiscal Year Final Research Report Summary
Functional Mechanism of Polymers for Papermaking : Fundamental Research Using Fluorescently Labeled Polymers.
| Project/Area Number |
63470119
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
林産学
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| Research Institution | Kyushu University |
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Principal Investigator |
TANAKA Hiroo Associate Professor, Faculty of Agriculture, Kyushu University, 農学部, 助教授 (20038243)
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| Co-Investigator(Kenkyū-buntansha) |
ABE Zensaku Assistant Professor, Faculty of Agriculture, Kyushu University, 農学部, 助手 (30091383)
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| Project Period (FY) |
1988 – 1990
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| Keywords | Fluorescent polymer / Polymer adsorption / Polymer desorption / Polymer conformation / Polymer exchange / Polymer transfer |
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| Research Abstract |
Cationic polyacrylamides (C-PAM) which contain both primary and quaternary amines were prepared according to the Hofmann reaction by adding choline chloride to a solution of PAM in water. The reaction was 90 % complete after 60 min at 20ﾟC. The degree of aniNation was over 70 % and the proportion of primary and quaternary amines could be altered widely by controlling the relative concentrations of NaOH, NaOCl and choline chloride.
C-PAM was dansylated (fluorescently labeled) in a homogeneous system using aqueous dimethylformamide as solvent. The optimum excitation wavelength for dansylated C-PAM (DC-PAM) in water was 333 nm and the corresponding emission wavelength 540 nm.
Series of C-PAMs in which (a) the molecular weight (MW) was constant (4x10*5) and the charge densities (CD) varied (0.65, 1.4 and 2.5 meq/g) and (b) the CD was constant (1.4 meq/g) and MWs varied (2x10*4, 4x10*5 and 8x10*6) were prepared with and without a fluorescent label.
The adsorption of these C-PAMs onto monodispe
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rse polystyrene latex (PSL) was very rapid regardless of MW and CD, but the adsorption rate onto cellulose fibers were significantly influenced by MW and CD due to the porous nature of fibers. A considerable degree of adsorption was, however, also rapidlyachieved in the case of fibers. The ratio of the charge of the adsorbed polymer to the charge of the substrate is discussed on the basis of the adsorption isotherms obtained. The fluorescent labeling had little effect on the adsorptivity of C-PAM on either PSL or fibers, probably because of the low degree of substitution.
The exchange reaction of C-PAMs on PSL and cellulose fibers have been studied using with the same MW and CD except that the pre-adsorbed polymers were fluorescently labeled. For C-PAM with the highest MW no significant exchange could be detected on PSL or on fibers. When C-PAM with the highest CD was used a slight exchange occurred on both PSL and fibers. On PSL the level of exchange was influenced only slightly by the time before displacement started (pre-adsorption time), and after 2 hr there was no further reduction in deabsorption. On fibers, on the other hand, the levels of exchange were affected significantly by the pre-absorption time, and the degree in exchange continued even after 3 weeks. The rates and levels of exchange were also influenced by the MW and CD.
For DC-PAM with different MWs, the rate of transfer from fibers to PSL 1 hr pre-adsorption time was in the following order, medium > high > low. It is interesting to note that DC-PAM with highest MW is transfered fairly easily considering that an exchange reaction for such a high MW does not take ple on PSL or on fibers described above. The effects of the CD of the polymer on polymer transfer were not great. When polymers transferred the cleavage of polymer chain occurred. The transferred fraction converged approximately to the ratio of charges of fibers and PSL. Less
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