关键词:

自交联, 封闭性, 双丙酮丙烯酰胺, 聚丙烯酸酯乳液

Abstract:

The ambient self-crosslinkable polyacrylate latexes with sealed function were synthesized by semi-batch seeded emulsion polymerization with diacetone acrylamide (DAAM), methyl acrylate (MMA), methacrylic acid (MAA) and butyl acrylate (BA) as co-monomers.The effects of DAAM and multiple emulsifiers on the emulsion polymerization stability and film performance were investigated.The results indicated that the emulsion polymerization stability decreased and the particle size of latex increased with increasing amount of DAAM, while the crosslinked degree of cured film increased and the water- or alcohol-resistance properties of cured film were improved.The optimal DAAM dosage was 3.0% (mass) and the molar ratio of DAAM to adipic dihydrazide (ADH) was 2∶1. On the other hand, the emulsion polymerization displayed high stability (low agglomeration and high monomer conversions), polyacrylate latexes exhibited good electrolyte stability, and its cured films possessed excellent sealed function.Sodium dodecyl sulphonate(SDS), nonyl phenol ethoxylates (OP-10) and OP-40 were used as multiple emulsifiers with 2.35% (mass) of the optimal dosage, the mass ratio of SDS to OP-10 and OP-40 was 1∶1.25, and the mass ratio of multiple emulsifiers dosages in seeded, core and shell was 1.5∶1∶2.The FTIR spectrum showed that the ketone carbonyl groups of DAAM reacted with hydrazide groups of ADH to form hydrazone (C=N) during film formation.TEM picture showed that the structures of particles were core and shell, and TGA curves indicated that the thermal stability of cured film decreased, which was attributed to the presence of C=N groups.

Key words:

自交联, 封闭性, 双丙酮丙烯酰胺, 聚丙烯酸酯乳液