Tack in Urethan Elastomers

Abstract

The phenomenon of tack has been studied in urethan—urea elastomers prepared from polyether or polyester prepolymers and 4,4′-methylenebis(2-chloroaniline). It is shown that tack at zero elongation is attained only in polymers in which the flexible chains, i.e., polyesters or polyethers, contain 50 chain links or more. This coincides with the requirements for the Gaussian vector function in elastomers. The results suggest that, in the absence of flexible chain ends in these polymers, tack is solely contributed by the flexible segments along the polymer chains, while the rigid blocks in the chains do not participate in the formation of tack.

The Effects of Processing on Interply Bond Strength of Thermoplastic Composites

“…The mechanism governing the formation of interply bonds has been established as autohesion or self-diffusion [2]. The theories and destructive mechanical tests characterizing autohesive bond development in thermoplastic resins are well developed [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. However, few studies were focused on the interply strength development during formation of a fiber-reinforced thermoplastic laminate.…”