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Date of Publication:2022-10-10

Journal:高分子学报

Affiliation of Author(s):经济管理学院

Issue:7

Page Number:931-936

ISSN No.:1000-3304

Abstract:Poly (phthalazinone ether nitrile ketone)s (PPENK) modified via hydrolysis of cyano groups with NaOH was studied in order to find a hydrophilic resin applicable to heat-resistant waterborne coatings. The propeties of hydrolyzates, HPPENKa (0.5 h), HPPENKb (1.5 h) and HPPENKc (3.5 h), were measured by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), contact angle (water) and solubility. The results indicated that the nitrile conversion ratio and T-g of hydrolyzates increased whereas the weight loss ratio of HPPENK decreased as hydrolysis time was prolonged. As expected, the hydrophilicity of HPPENK was improved greatly, e. g. when CN conversion ratio was 93.82% the water contact angles was decreased from 75.3 degrees of PPENK to 54.4 degrees of HPPENK. By studying the effect of the reaction co-solvents, reaction temperature and NaOH concentration on hydrolysis,the optimal synthetic technology was found to be reaction at 120 degrees C with 6 mol/L NaOH solution and DMAc as co-solvent. Aqueous dispersions based on three modified resins were prepared and their storable stability were listed as follows: HPPENKc > HPPENKb > HPPENKa. Especially, the deposition of HPPENKc dispersion was not found after more than 30 days. The structures of hydrolyzates were characterized by FT IR,H-1-NMR.

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