Unsaturated Polyesters with Pendant Double Bonds and Investigation of their Self Curable Activity

In this paper, the self-curable unsaturated polyester was put forward as a new solution to air pollution problems caused by the cross-linking monomer’s volatilization in unsaturated polyesters (UP) industry. Two kinds of unsaturated polyesters with the vinyl double bonds at the side chain were synthesized with Itaconic acid (IA) or Itaconic anhydride (ITA) as raw materials. The first one was prepared with IA, isophthalic acid and propylene glycol (IPP-UP), and the second one was synthesized with glycidol (GL) and ITA (IG-UP). Investigation demonstrates that the latter UP resin could be self-cured through the nucleophilic addition reaction of hydroxyl groups with double bonds or the free-radical homopolymerization of double bonds when they were heated without cross-linking monomers. However, the former couldn’t. Factors on self-crosslinking activity and crosslinking mechamism of pendant vinyl bonds from IA or ITA were explored.1H-NMR and FT-IR were used to characterize.