Preparation And Study Of High Performance Water-borne Alkyd Resin Emulsion

Alkyd resin coatings have many advantages with good film properties, cheap, readily available raw materials, mature and stable technology, not petrolic depended. . But traditional alkyd resin coatings are solvent-based, when prepare and process the solvent vaporize into the environment and are danger for human body. With the increased awareness of environmental protection and the implementation of environmental regulations, research on the environmentally friendly water-borne alkyd resin coatings have taken more and more attention. How to have good water dispersible, the resin film performance and cheap materials at the same time, that is the hot problem need researchers try to solve.In this paper, in order to obtain waterborne alkyd binders which not only has emulsion stability but also has good film performance, we detailed studied the TMA modified alkyd resin, acrylic-modified alkyd in the main chain and acrylic-modified alkyd in the side chain.(1) TMA modified alkyd resin: Alcoholysis method was adopted to synthesize the alkyd resin. Used linseed oil, phthalic anhydride, trimethylolpropane as the row materials,synthesized the resin,then trimellitic anhydride and maleic anhydride modified it to obtain carboxyl in the side chain. From calculation and experimental revise, we get affable basic parameter (K), oil length (L), alcohol surplus (R), to sythesis the best performance modified resin. The results show that the alkyd resin synthesized from the technology has a poor storage stability with water, and film drying time and hardness are not good enough.(2) Acrylic-modified alkyd in the main chain:Used linseed oil, trimethylolpropane, acrylic monomers(MAA, MMA, AA, BMA) as raw materials, synthesized a kind of acrylic-modified alkyd in the main chain. Mainly by adjusting the ratio of acrylic monomers and the amount of acrylic polymer to obtain the best modfied alkyd resin. The outstanding of the technology is that polyacid acrylic copolymers are used as di- and tri- acids thatare used normally in producing of alkyd resins.From the experiment, the resulted resins are readily diluted with water and had good hydrolytic stability.But the resulted resin binders film can not dry in one week, so there need more work to cut down the drying time.(3) Acrylic-modified alkyd in the side chain: Used linseed oil, trimethylolpropane, phthalic anhydride,maleic anhydride and acrylic monomers(MMA, AA,styrene) as raw materials, synthesized a kind of acrylic-modified alkyd in the side chain. Mainly by adjusting the ratio of each acrylic monomers, the ratio of basic alkyd resin and acrylic monomers amout, extent of neutralization, the ratio of maleic anhydride and phthalic anhydride to obtain the best modfied alkyd resin. From the national standard, we get the follow data: storage stability more than six months, hardness and adhesion equal to level one, impact resistance more than 50cm, hydrolysis resistance more than fourteen hours and equal to level one. So it is a kind of modified alkyd resin which is readily diluted with water and has a good film performance.