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/m ethyl methacrylate copolymer latex particles of different composition profi les (constant, positive, and negative gradients) but similar molecular weig ht distributions were studied. The composition profile had a strong effect on tack in the region of low molecular weights (weight-average molecular we ight less than or equal to 100,000 g/mol), but this effect was less importa nt for higher molecular weights. No effect of the composition profile on sh ear or peel was observed for low-molecular-weight latices; nevertheless, fo r higher molecular weights (400,000 g/mol), resistance to shear strongly in creased as heterogeneity increased, and resistance to peel was higher for g radient profiles. (C) 2001 John Wiley & Sons, Inc.