Abstract
The relationship of joint strength of solvent weided joints of polycarbonate to their microstructure is investigated. We used three solvents - butanone, acetone, and cyclohexanone - to test the effect of solubility parameters, and a mixture of cyclohexanone with ethanol to test the effect of a cosolvent; the effect of variation of welding temperature-on both the joint strength and the microstructure is also investigated. Three fracture modes in shear, tensile and tear tests are analyzed. Polycarbonate treated with butanone has maximum joint strength. Cyclohexanone at 78 vol% in ethanol produces the maximum joint strength of polycarbonate. The joint strength of polycarbonate joints welded with cyclohexanone increases with the temperature at which the wead is made. Comparing microstructure with joint strength, tongues, equiaxed dimples and elongated dimples are responsible for the maximum shear, tensile and tear strength, respectively.