Leather is a material created through the tanning of Hides and skins of animals, primarily cattle hides. The tanning process converts the putrid skin into a durable, long-lasting and versatile natural material for various uses. In mechanical case, leather can be used as fiber especially natural fiber. Structural materials can be divided into four bases: metal, polymer, ceramic and composite. Composite, which consists of two or more separate materials combined in macroscopic structural unit. Contact angle (θ) measurement is one of the simplest methods to determine interface compatibility between two surfaces in which they were bonded or stacked together. Leather as a candidate material for reinforcement in polymer matrix composite must be investigated in order to obtain optimum wet-ability between fiber and matrix. In this research contact angle measurement between leather surface and polymer epoxy and polypropylene was conducted in digital microscope or camera and angle measurement was assisted by software. Leather was divided into two types, finish leather and crust leather, each with no treatment, emboss and flash respectively. Epoxy and polypropylene were directly applied to leather surface. The result showed that epoxy matrix had contact angle (θ) lower than polypropylene matrix applied to crust and finish leather surfaces. At finish leather polipropelin matrix showed an average cos θ = 0,817 at no treatment, 0,882 at emboss, 0,722 at flash leather and epoxy matrix more than 0,883. And Polipropelin matrix showed an average cos θ = 0,809 at no treatment, 0,800 at emboss, 0,492 at flash leather and epoxy matrix more than 0,938, at crush leather. Higher cos θ means good wet-ability. It could be stated that epoxy had a better wet-ability to leather fibers than polipropelin matrix.
Keywords : leather, composite, wet-ability