Supporting Information
Effect of alkali-soluble resin emulsifiers on coalescence and interdiffusion between latex polymer particles
Edurne Gonzalez, Christopher Tollan, Andrey Chuvilin, María Paulis, María J. Barandiaran
Synthesis of MMA/BA latex
The MMA/BA (50/50 wt %) latex at 40 % solids content (s.c.) was produced by seeded semibatch emulsion. Initially, a seed with MMA/ BA (50/50 wt %) at 10 % s.c. was prepared with SLS (1% weight based on monomers, wbm) and V-501 (1% wbm) in a 1000 mL glass jacketed reactor equipped with a reflux condenser, a nitrogen inlet, a sampling device, a stainless steel modified anchor stirrer rotating at 250 rpm, and a cascade temperature control system (Camile TG, Biotage). The seed was used for the seeded semibatch emulsion copolymerization of MMA/BA (50/50 wt %) at 40 % s.c. The semibatch polymerization was carried out as follows: The reactor was loaded with the desired amount of the polymer seed (20 wt %) and part of the water, and the temperature was increased to 70 °C. Upon achieving the required temperature, the initiator (V-501, 1% wbm), dissolved in water (6 wt %, adding a stoichiometric amount of NaOH), was introduced in a shot and the rest of the ingredients were fed in one stream containing the preemulsion of MMA and BA (62% s.c and SLS 1% wbm) to achieve a final solids content of 40%. After the feeding period (4 h) the system was allowed to react in batch for one hour more. Total conversion was achieved. The gel fraction of the final latex was determined by soxhlet extraction in THF and the molecular weight of the THF soluble part was analysed by GPC in THF solution [1].
ESEM images
ESEM images for the latex (Tg: 18 ºC) stabilized by 8 wt % of ASR171 obtained at different temperatures, in all the cases the pressure was 270 Pa. The length of the scale bar is 5 µm
[1] O. Elizalde, G. Arzamendi, J.R. Leiza, J.M. Asua, Seeded Semibatch Emulsion Copolymerization of n-Butyl Acrylate and Methyl Methacrylate, Ind Eng Chem Res, 43 (2004) 7401-7409