Synthesis and application of formaldehyde free melamine glutaraldehyde amino resin as an effective retanning agent

Novel melamine based free formaldehyde resin using glutaraldehyde as a condensing agent rather than formaldehyde has been synthesized under optimum conditions for use as a retanning agent. Characteristics and effects of the polymer as a retanning agent have been investigated against conventional melamine formaldehyde resin. Tear strength, tensile strength, elongation at break, and scanning electron microscopy (SEM) of experimental retained leather have been studied in comparison with commercial melamine formaldehyde retanned leather and are found to be in better performance. Effluent emission of both retanning baths have been evaluated and found to contain less effluent load in experimental bath, thus less impact on the environment. Glutaraldehyde alone affects dying process and produces problem in leveling of shade. In this study, dispersing and leveled dying property of glutaraldehyde have also been improved after condensing with melamine. Both experimental and conventional melamine resins have shown good dispersing and leveling property in dying process of retanned leather. Structural elucidation of the experimental resin has been carried out by FUR technique.