Synthesis of amphiphilic copolymers based on acrylates by free-radical polymerization and their application in alkyd emulsions

Novel amphiphilic copolymers which contained poly(ethylene glycol) side-cha in, long-chain alkyl pendant groups, and carboxyl groups have been synthesi zed by the conventional free-radical copolymerization of special monomers. The products were characterized by analysis of Fourier transform infrared s pectroscopy (FT-IR), Gel Permeation Chromatography (GPC), and H-1 NMR. Base d on the measurement of surface tension of aqueous copolymer solutions with various concentrations at an air/water interface, the critical micelle con centrations (CMC) was found to be lower along with the increase of copolyme r concentration. Experimental results showed that CMC of this kind of amphi philic polymer appeared in the range of 0.01 similar to0.1 g/L. The amphiph ilic polymer was mixed with an anionic surfactant (SDBS) in different propo rtions at aqueous solution and then successfully used in the preparation of alkyd emulsions. The results were compared with those of alkyd emulsions w ithout polymeric surfactant. Steric stabilization of amphiphilic polymer wa s investigated by the observation of the stability of alkyd emulsions. The emulsions were stable after resting at ambient temperature for four months.