Physical And Chemical Properties Of Rosin

Rosin can be divided into three types based on its source: resin rosin, wood rosin, and floating oil rosin. Rosin, also known as rosin, has a light color, high acidity, and a high softening point; Pinus massoniana, also known as extracted rosin, is inferior in quality to resin rosin, has a dark color, low acidity, and is prone to crystallization from certain solvents; Floating oil rosin, also known as tall oil rosin. Rosin is a transparent and brittle solid natural resin, which is a complex mixture composed of resin acids (abietic acid, sea pine acid), small amounts of fatty acids, rosin anhydride, and neutral substances. The main component of rosin is resin acid, accounting for about 90%, with a molecular formula of C19H29COOH and a molecular weight of 302.46. Resin acid is the most representative rosin acid, belonging to unsaturated acids, containing conjugated double bonds, strongly absorbing ultraviolet light, and can automatically oxidize or induce post oxidation in air. Rosin has a light yellow to light brown appearance, with a glassy luster and a turpentine odor, with a density of 1.060-1.085g/cm3. Belonging to amorphous, without a melting point, with a softening point (global method) of 72-76 ℃ and a boiling point of approximately 300 ℃ (0.67 kPa). The glass transition temperature Tg is 30-38 ℃. The refractive index is 1.5453. Flash point (open cup) 216 ℃. The ignition point is approximately 480~500 ℃. Easy to oxidize in the air and darken in color.