Layered double hydroxides as transesterificationcatalysts and nanofillers for polyester resin (in English)
Polimery 2015, No 3, 160
Saturated polyester resins were prepared by reaction of dimethylterephthalate with alkylene glycols in the presence of layered doublehydroxides (hydrotalcites, HT). The effect of HT composition (cation and aniontypes) on the rate and progress of transesterification was investigated. It wasfound that zinc-aluminum HT intercalated with anionic form of aminolauric acid[HT(ZnAl)ALA] efficiently catalyzes transesterification process, increasing therate of reaction or lowering its temperature when compared to the reaction withuse of conventional organic tin catalyst. The polyester resin obtained in thisway is transparent, which along with X-ray diffraction data indicates thedelamination of clay layers and formation of nanocomposite. The limitation ofusing ALA-intercalated HT as an additive for polyesters used in coatings iscoloration of the resin with an increase of the reaction temperature above 180°C. Colorless polyester was obtained using more thermally stable hydrotalciteintercalated with ethylenediaminetetraacetic acid, however, at the expense ofsignificantly longer reaction time. Using HT(ZnAl)ALA catalyst atwo-stepsynthesis of carboxyl polyester resin was performed and the obtained productwas used as acomponent of powder coating formulation.