An isocyanate-terminated hyperbranched polymer (HBI) was successfully synthesized by reacting hyperbranched polyester (Boltorn^TM HB-20) with isophorone diisocyanate (IPDI). Gel permeation chromatography (GPC) was used to monitor the molecular weight and its distribution changes during the synthesis. The structure and composition of IPDI were characterized by ¹H and ¹³C nuclear magnetic resonance (NMR) spectroscopy. The structure of HBI was confirmed by one-dimensional ¹H, ¹³C NMR, and distortionless enhancement by polarization transfer (DEPT) NMR spectroscopy as well as two-dimensional heteronuclear multiple bond coherence (2D-HMBC) and heteronuclear single quantum coherence (HSQC) NMR spectroscopy. Furthermore, HBI was reacted with methoxypolyethylene glycols (MPEG) to obtain a water-dispersible polyisocyanate with hyperbranched structure.

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