Synthesis And Application Of Sodium Octylphenol Polyoxyethylene (10) Itaconate Monoester

In emulsion polymerization, the use of polymerizable surfactants is becoming popular. The purpose is to covalently bind the surfactant molecules to the polymer particles surface, which can improve the properties in terms of latex stability and water resistance after film formation. Itaconic acid (IA) is listed as one of the "top value-added chemicals from bio-mass" by the US Department of Energy. It has drawn increasing attention due to its wide applications and the development of its derivatives. The preparation of polymerizable surfactants using IA as the raw material instead of petroleum-based materials can reduce the dependence of petroleum industry, and meet the direction of industrialization of surfactants.In this paper, the polymerizable surfactant, i.e. sodium octylphenol polyoxyethylene (10) itaconate monoester (SOP10IM), is synthesized by esterification of itaconic acid and octylphenol polyoxyethyene ether (10) (OP-10) and then the neutralization with sodium hydroxide solution. The effects of the molar ratios of the raw materials, the catalyst type, amount of the catalyst, reaction temperature and reaction time on the esterification rate are observed. And the optimal conditions for reaction are determined:the molar ratio of IA to OP-10 is 1.05:1, p-toluenesulfonic acid as the catalyst, and the catalyst content 4.0% relative to the mass of IA, the reaction temperature 120 ℃, and the reaction time 4.0 h. The esterification rate is 93.1%　under the optimal reaction conditions.At 25 ℃, the critical micelle concentrations (CMC) of aqueous SOP10IM solution are 1.0 × 10-4mol/L and 8.0 × 10-4mol/L at pH-5 and pH= 8, respectively. The surface tensions of the resultant surfactant at CMC (γyCMC) are 31.08 mN/m and 31.51 mN/m, respectively. In addition, SOPioIM has good emulsifying capacity, foaming and dispersing property; By means of emulsion polymerization, it is shown that SOP10IM can be easily copolymerized with methyl methacrylate and vinyl acetate, and covalently bound on polymer particles surface.The SOPioIM, as an emulsifier, can be applied in the preparation of pigment adhesive. It is found that the adhesives prepared from the optimum reaction conditions have better application results, and the optimum reaction conditions are as follows:the reaction temperature is 85 ℃, reaction time 1.5 h, initiator concentration 0.4 wt%, w(SOP10IM):w(SDS)= 8:1-7:1, and emulsifier concentration 4.0 wt%, respectively. Finally, the films formed of the latexes synthesized with SOP10IM have better stability, water resistence, and wet and dry rubbing fastness than those prepared by traditional emulsifier OP-10.