Abstract: An aqueous copolymer dispersion is obtained by a multi-stage emulsion polymerization process comprising polymerizing in a reaction zone in a first polymerization stage a first monomer composition comprising at least 88 wt % of a vinyl ester of a C1 to C18 carboxylic acid and up to 12 wt % ethylene to produce a first stage polymer having Tg>20° C.; and polymerizing in the reaction zone, in a second polymerization stage and in the presence of the first stage polymer, a second monomer composition comprising a vinyl ester of a C1 to C18 carboxylic acid and a C2 to C8 alkyl ester of (meth)acrylic acid to produce a second stage polymer having Tg?20° C. Each of the polymerization stages is conducted in the presence of a stabilizing system comprising at least 0.1 wt % of a protective colloid and at least 0.05 wt % of an ionic surfactant.

Abstract: A film containing an aromatic polyester with aromatic biphenyl repeating units having the following general Formula I: is provided. The film is annealed and exhibits a relatively isotropic tensile property.