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Handbook of Solvents - George Wypych - ChemTech - Ventech!

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846 Norio Tsubokawa<br />

more easily than in DMAc (PAI-2 and<br />

PAI-4). This is due to the fact that PAI-1<br />

and PAI-3 contains more carboxyl groups<br />

than PAI-2 and PAI-4.<br />

13.4.4 CONCLUSIONS<br />

The effects <strong>of</strong> polymerization solvent on<br />

the curing <strong>of</strong> PAIs were investigated and<br />

the following results were obtained:<br />

(1) The carboxyl group content <strong>of</strong><br />

PAIs from PAAAs prepared in MEK/H2O mixed solvent was larger than that in<br />

Figure 13.4.2. Relationship between heating temperature<br />

and insoluble part <strong>of</strong> PAI samples after heating (2h) in air DMAc.<br />

[Data from reference 7].<br />

(2) The curing <strong>of</strong> PAIs prepared in<br />

MEK/H2O proceeded easier than those in<br />

DMAc.<br />

(3) The curing <strong>of</strong> PAIs by heating was due to the intermolecular reaction between<br />

functional groups <strong>of</strong> PAIs, such as carboxyl and amino groups.<br />

REFERENCES<br />

1 M.Fujita and T.Fujita, Rubber Digest, 18 (1), 21 (1966).<br />

2 S.Terney, J.Keating, J.Zielinski, J.Hakala, and H.Sheffer, J. Polym. Sci., A-1, 8, 683 (1970).<br />

3 Y.Imai and T.Takahasi, Kobunshi Kagaku, 29, 182 (1972).<br />

4 N.Tsubokawa, I.Yamamoto, and Y.Sone, Kobunshi Ronbunshu, 44, 389 (1987).<br />

5 N.Tsubokawa, I.Yamamoto, and Y.Sone, Kobunshi Ronbunshu, 44, 831 (1987).<br />

6 H.Uchiyama and Y.Imai, Kobunshi Kagaku, 28, 73 (1971).<br />

7 N.Tsubokawa, M.Murata, and Y.Sone, Netsu Kokasei Jushi, 12, 12 (1991).

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