Effect of physical aging and thermal stress on the behavior of polyester/TGIC powder coatings

• Published in: Progress in organic coatings Vol. 40; no. 1; pp. 215 - 224
• Main Authors: van der Linde, Rob, Belder, Eim G., Perera, Dan Y.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.12.2000; Elsevier Sequoia
• Subjects: Applied sciences; Coatings. Paints, varnishes and inks; Exact sciences and technology; Film formation and curing, properties, testing; Physical aging; Polymer industry, paints, wood; Powder coatings; Terephthalic and isophthalic acids; Thermal expansion; Thermal stress; Triglycidyl isocyanurate; Powder coatings; Thermal stress; Thermal expansion; Physical aging; Terephthalic and isophthalic acids; Triglycidyl isocyanurate; Isophthalic acid; Coating material; Enthalpy; Ageing; Ester polymer; Terephthalic acid; Mechanical properties; Paint film; Powder paint; Experimental study; Structure relaxation; Thermal properties; Compressive stress; Crosslinked polymer
• ISSN: 0300-9440; 1873-331X
• DOI: 10.1016/S0300-9440(00)00125-9

Physical aging, thermal stress, dynamic mechanical characteristics and thermal expansion of powder coatings from model terephthalic acid (TPA) and isophthalic acid (IPA)-based polyesters (PEs) cross-linked with triglycidyl isocyanurate (TGIC) were studied. Enthalpy relaxation and maximum compressive thermal stress were the properties used to follow the physical aging. The better mechanical properties of TPA-based PE/TGIC powder coatings seem to be due to a combined effect of several properties, i.e., cross-link density ( ν e), thermal expansion coefficient ( α F T) and glass transition temperature ( T g). The higher the values of ν e, ( α F T) and T g, the tighter is the coating network, the greater is the coating ability to expand thermally and the slower the physical aging process, respectively, all factors favoring the TPA polyester-based powder coatings.