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Progress in Chain Extender Evaluation for Polyurethanes Derived from Hydroxyl-Terminated Polybutadiene Resins Presented by Dr. Herbert S. Chao |
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Paper Abstract Chain extender plays a significant role in enhancing the final mechanical properties of the polyurethanes derived from hydroxyl-terminated polybutadiene (HTPB) and 4,4’-methylenebis(phenyl isocyanate) (MDI). Conventionally, N, N-diisopropanol aniline (DIPA) and 2-ethyl-1,3-hexanediol (EHD) are recommended for their compatibility and physical property enhancement of the polyurethane elastomer. By comparison, 1,4-butanediol (BDO), widely employed in polyurethanes based on polyether or polyester polyols, is not a good choice owing to its poor compatibility with HTPB resins. A systematic screening of both aromatic and aliphatic diols as potential chain extenders in standard HTPB-based polyurethane formulations has been carried out. Although no good correlation could be drawn between the diol structure and mechanical performance, two new aliphatic diols were notable for its superior performance. |
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