respectively. The particle sizes of the three samples (MENR, NR-g-CSt and NR-g-CSt/MENR blend latex) were also determined using a micro-electrophoresis apparatus (Zetasizer 4, Malvern) at 25◦C,in a pH 7 medium. A known weight of the graft copolymer film of specific dimensions (2.5 cm × 2.5 cm × 0.5 mm) was immersed in toluene, benzene oil and water for a period of 5 days at 32◦C.The sample was dried in an oven at 50◦C for 24 h and then weigheduntil a constant weight was achieved. The %swelling was calculated from Eq. (2) as follows:
%Swelling
=
(W2 − W1)/W1 × 100 (2)where
W1= original weight of the sample, W2= weight of theswollen sample