FTIR SPECTROSCOPY AND MICROSCOPY ON THE INTERFACIAL REACTION AND INTERDIFFUSION OF STYRENE MALEIC ANHYDRIDE COPOLYMER AND BIS(AMINE)-TERMINATED POLY(TETRAHYDROFURAN)/

The interfacial reaction of a random copolymer of styrene and maleic a nhydride (SMA) with bis(amine)-terminated poly(tetrahydrofuran) (PTHF) is studied by FTIR spectroscopy and microscopy as a function of tempe rature and for two different PTHF molecular weights. The reaction rate constants in the range from 170 to 230 degrees C, obtained from the i nitial slope of conversion-time plots, give values between 3.6 x 10(-5 ) and 2.5 x 10(-4) s(-1). It can be shown that the diffusion of the PT HF into the SMA phase occurs prior to the imide formation. Thus the im ide is formed in the SMA phase and can be estimated quantitatively by the appearance of the imide peak at 1702 cm(-1) and the decrease of th e out-of-phase carbonyl stretching vibration of the maleic anhydride a t 1780 cm(-1). The concentration profiles near the interface of the us ed polymers and the formed imide are studied by FTIR microscopy.