Institute of Materials Science
University of Connecticut
How is adhesion between two plastics enhanced when polymer chains interpenetrate? Recent observations show that bonding of BPA polycarbonate (PC) to poly(butylene terephthalate) [PET] occurs in 10 minutes at temperatures above the glass transition of the PC. In 20 minutes at 216oC, fibrils are observed to grow from the PET into the PC; the kinetics of fibril length versus t1/2 are characteristic of a diffusion-controlled process. Adhesion between the two partially miscible polymers is explained by a model involving diffusion of PET into PC, moderated by the effects of temperature on solubility.
S.Y. Hobbs, V.H. Watkins, J.T. Bendler, "Diffusion bonding between BPA polycarbonate and poly(butylene terephthalate)," Polymer, 31, 1663-8, September 1990. (General Electric Corporate Research and Development, Schenectady, N.Y.)
The interface between two polymers can be imaged without staining if electron energy loss spectroscopy (EELS) is combined with electron microscopy....