A new diamine monomercontaining a built-in

stabilized ortho ester group was synthesized by diglycerol with two steps of transesterification. Two new highly hydrophobic copolymer poly (ortho ester amide) (POEAd-1 and POEAd-2) were obtained by polycondensation ofthe monomer with suberic acid bis (N-hydroxysuccinimide ester) and dodecanedioic acid bis( N-hydroxysuccinimide ester). The number average molecular weight of POEAd-1 and POEAd-2 were determined by gel permeation chromatography (GPC)

and calculated to be 1.24 × 10

4

and. 1.81 × 10

4

with polydispersity index(PDI) of 1. 59 and 1.93

respectively. Thermal stabilityof POEAd-1 and POEAd-2 via thermogravimetric analysis ( TGA) were investigated)

the temperature of the onset 5 % weight loss is up to 198. 5℃ and 202. 5℃

respectively. Hemolysis test and MTT cytotoxicity test indicate that POEAd-1 and POEAd-2 has good biocompatibility as a potential biomedical materials

can bewidely used in the field of controlled drug deliever.