The effect of diacetone acrylamide and adipic acid dihydrazide as a crosslinker system on styrene/acrylate emulsion

Styrene/acrylate emulsion polymers are the most popular polymers applied to paint. They have low volatile organic compounds (VOC) so they are eco-friendly. Recently, the preparation of crosslinked emulsion has become the most effective method to improve its properties. Herein, the crosslinked styrene/acrylate emulsion was prepared by using various ratios of diacetone acrylamide (DAAM) and adipic acid dihydrazide (ADH) as a crosslinker system, where DAAM: ADH (g: g) was 5:1.25, 5:2.5, and 2.5:1.25 to get samples C1, C2, and C3, respectively. The prepared emulsion was investigated by transmission electron microscopy (TEM), storage stability, viscosity, solid content, particle size distribution, and zeta potential. In addition, the films obtained from the as-prepared emulsion were characterized by Fourier transform infrared (FT-IR) and thermogravimetric analysis (TGA), also, their wet scrub resistance and gloss properties were determined. The data showed that the prepared emulsion has solid content in the range of 49 % and a density in the range of 1.01 g/cm3. The samples C1, C2, and C3 show particle sizes 148, 147, and 166 nm, respectively, and zeta potentials -49.7, -50.1, and -52.9 mV, respectively, while the blank (BL) shows particle size of 201 nm and zeta potential of -43.3 mV. Furthermore, sample C2 shows the best washability (18000 cycles) compared to sample BL (3300 cycles). In addition, the thermal stability, and gloss of the crosslinked latex were improved by the addition of crosslinkers in comparison with the BL.