The hyperbranched polyester Boltona I-I20 contains a lot of hydroxyl groups, the reflux condensation method was adopted, some hydroxyl groups of H20 was modified with maleic anhydride, thereby some carboxyl groups different solvents and modified hydroxyl number were introduced in the H20. The effect of on the reaction time were discussed. Reaction end point was determined with FTIR, NMR spectroscopy confirmed that Boltorn H20 was successfully modified with maleic anhydride, this may be usefull for further study of...
