Preparation And Performance Characterization Of Dodecanedioic Acid Modified Copolyester Hotmelt Adhesive

The copolymerization modification is an important method to improve the performance of polyester hotmelt adhesives. In this article, polyester hotmelt adhesive was prepared from terephthalic acid (PTA), isophthalic (PIA) and 1,4-butanediol (BDO). Dodecanedioic acid (DCA) was added as modified component.Firstly, the kinetic data of the esterification between dodecanedioic acid and 1,4-butanediol were determined. A kinetic model was established based on Flory’s thoery. Effects of the amounts of the catalyst used, the ratio of reactants and the reaction temperature were investigated. The results showed that the reaction rate increased with the increase of reaction temperature. The reaction activation energy was 69.39 kJ/mol.Secondly, poly (butylene-terephthalate-co-isophthalate-co-dodecanedioate) (PBTID) adhesives have been synthesized. The influence of DCA content and TPA/IPA ratio when the DCA content was quantified on the properties of the copolyester were explored. With the increase of DCA content, the glass transition temperature and melting point of the copolyester reduced and the open time extended, the tenacity of the copolyester improved; while the TPA/IPA ratio decreases, the melting point and softening point of copolyester lowered, the open time decreased.Finally, a method of drawing wire for preparing sample used in evaluating adhesion performance of hotmelt adhesives was proposed. The effects of wire diameter and the fusion press temperature on the adhesion strength of the laminate samples were explored. The appropriate diameter and press temperature range were obtained. The adhesion strength of the dodecanoic acid modified copolyester hot melt adhesive was tested and the results showed that when TPA/IPA/DCA molar ratio was 43:43:14, the adhesion strength was the best.