The levelling performance of polyester powder coating is not as well as liquid coating due to its matrix polyester resin. 1,6-hexanediol (HDO), neopentyl glycol (NPG), terephthalic acid (PTA), isophthalic acid (IPA) were used to synthesize semi-crystalline polyester resin (HDO, PTA and IPA) and amorphous polyester resin (NPG, PTA and IPA). The semi-crystalline polyester resin was introduced to powder coating for further use. The structure of semi-crystalline polyester resin was characterized by 1H-nuclear magnetic resonance (1H NMR) and X-ray powder diffraction (XRD). The viscosity of the polyester resins were investigated by cone-and-plate viscometer (CPV). The reactivity of the coatings was characterized by differential scanning calorimetry (DSC). The levelling performance was studied by flow, cone-and-plate viscometer (CPV), atomic force microscope (AFM) and scanning electron microscope (SEM). The results showed that the semi-crystalline polyester powder coating had higher reactivity and better levelling performance than that of amorphous polyester powder coating.
Yong Li,Liang Liu,Yuxin Gu,Jing Xie,Jie Zhang,Jinqing Qu.
Progress in Organic Coatings,99,191-196(2016)