Properties of Polymers Isotactic and syndiotactic polymers are stronger and stiffer due to their regular packing arrangement. Anionic intermediate usually gives isotactic or syndiotactic polymers. Free radical polymerization is nearly random,giving branched atactic polymers. => Chapter 26 11Chapter 26 11 Properties of Polymers • Isotactic and syndiotactic polymers are stronger and stiffer due to their regular packing arrangement. • Anionic intermediate usually gives isotactic or syndiotactic polymers. • Free radical polymerization is nearly random, giving branched atactic polymers. =>