Effect of the composition profile of 2-ethyl hexyl acrylate/methyl methacrylate latex particles on adhesion

The adhesive properties (tack, shear, and peel) of 2-ethyl hexyl acrylate/methyl methacrylate copolymer latex particles of different composition profiles (constant, positive, and negative gradients) but similar molecular weight distributions were studied. The composition profile had a strong effect on tack in the region of low molecular weights (weight-average molecular weight less than or equal to 100,000 g/mol), but this effect was less important for higher molecular weights. No effect of the composition profile on shear or peel was observed for low-molecular-weight latices; nevertheless, for higher molecular weights (400,000 g/mol), resistance to shear strongly increased as heterogeneity increased, and resistance to peel was higher for gradient profiles. (C) 2001 John Wiley & Sons, Inc.