Structure and Thermal Properties of Polyurethanes Synthesized from Cardanol Diol

Abstract

© 2015, Springer Science+Business Media New York. Amorphous polyurethanes (PUs) were prepared from isophorone diisocyanate and various diols based on ethylene glycol, containing phenol (PD), hydrogenated cardanol (HCD) and cardanol (CD) as side groups. The influence of side groups on thermal and thermo-oxidative stability was studied by thermogravimetric analysis and differential scanning calorimetry. The finding revealed that pendent C15 alkyl side groups of HCD–PU and CD–PU improved thermal stability of PUs. The possible crosslinks of olefinic side groups enhanced both thermal and thermo-oxidative stability of CD–PU. Both EG–PU and CD–PU exhibited good oxidative resistance. The glass transition temperature arranged in the order of EG–PU > PD–PU > HCD–PU > CD–PU. Cardanol molecules on PU backbones acted as an internal plasticizer and elevated the flexibility of PUs.