Synthesis and application of a novel aromatic hyperbranched polyester

New aromatic AB(2)-type monomer propyl 3, 5-(dihydroxyethoxy) benzoate PDEB was synthesized by two steps, firstly the esterification of 3, 5-dihydroxy benzoic acid by propanol, then the alkoxylation of the intermediate product with 1-chloroethanol. By polycondensation of PDEB, a hyperbranched aromati c polyester with aliphatic chain segments was effectively prepared. The str ucture of the product was analyzed by IR, H-1 NMR, DSC, TGA and viscosity m easurements. The results showed that the T-g of PPDEB decreased sharply wit h little change in t(d) compared with that of the analogous polymer without aliphatic chain linkages. The rheologic property of PC was, improved great ly with the addition of PPDEB.