Synthesis, aggregation and dispersity properties of novels amphiphilic comb-like terpolymers

- Three polycarboxylate-based comb-like terpolymers were synthesized as designed.
- Surface tension, TEM and DLS were used to study their aggregation behavior.
- Target terpolymers form the aggregates of primary micelles in solution.
- Target terpolymers have good dispersive capacity.
- Target terpolymers show excellent thermal stability.

Three polycarboxylate-based comb-like random terpolymers (PAE-Na) were designed and synthesized by emulsion polymerization. Their structures were confirmed by FT-IR, 1H NMR and GPC. Their surface activities, aggregation behaviors and dispersity properties in aqueous solution were investigated by surface tension measurements, dynamic light scattering (DLS) and transmission electron microscopy (TEM). Investigation of the surface tension indicates that polycarboxylate-based copolymers have good surfactivity due to the introduction of 2-ethylhexyl acrylate (2-EHA). And it is noteworthy that γ continuously decreases after critical aggregation concentration (CAC). TEM and DLS results indicate that they can form the aggregates of primary aggregates. The dispersibility of terpolymers as dispersant for CaCO3 suspensions was evaluated. The results show that the target polymers have good dispersive capacity. The thermogravimetric analysis indicates that terpolymers have excellent thermal stability, which could be used to disperse solid particles in many different fields.

189TEM images of CaCO3 particle suspensions: 9a is the TEM of CaCO3 particles without dispersant, 9b-9d are the TEM photos of CaCO3 particles with 1% dispersant of 1#, 2# and 3# terpolymers. TEM was carried out to offer intuitive morphology and size of CaCO3 particle suspension. It can be seen that the addition terpolymers can significantly improved the dispersity of CaCO3 particles. Particllarly, the addition of 2# and 3# terpolymers can prevent the agglomeration of CaCO3 remarkably.