Castor Oil-Based Polyester Polyol COPE-200

COPE-200 is synthesized from castor oil (ricinoleic acid) and short-chain diols/diacids, incorporating the natural triglyceride structure into the polyester backbone. Key performance differences from petroleum polyester polyols: (1) Inherent flexibility — the long ricinoleic acid chain (C18) introduces soft segments without requiring high MW, enabling good flexibility (elongation 100–250%) at the relatively high OH value of 190–210; (2) Hydrophobicity — the aliphatic nature of ricinoleic acid gives COPE-200 lower water absorption than ethylene glycol adipate equivalents; (3) Bio-based carbon — ≥70% USDA-measured renewable carbon satisfies green procurement specifications for government buildings and eco-label programs. The trade-off versus petroleum polyols is batch-to-batch color variation (Gardner 1–4) and seasonal supply fluctuation tied to castor crop yields.