The main disadvantages of thermoplastic starch(TPS) are their retmgradation and unsatisfactory mechanical properties particularly under wet or dry environments．Formamide was used as an individual plasticizer to prepare thermoplastic starch (TPS) to overcome the facile retmgradation of polyols-plasticized TPS with good mechanical properties or the poor mechanical properties of urea-plasticized TPS with good retrogradation resistance By using scanning electron microscope (SEM) the native cornstarch granules wele proved to transfer to a continuous phase with out crystallinity after plasticization with formamide By theology tests

it was shown that formanfide made TPS less temperature sensitive than glycerol did in the processing temperature range of formamide-plasticized TPS (FPTPS) from 110℃ to 150℃ Thermal analysis reveals that glycerol-plasticized TPS (GPTPS) exhibits better thermal stability and FPTPS has a slightly lower glass transition temperature The effect of water contents on the mechanical properties of FPTPS and GPTPS was also studied．and FPTPS showed good ductility at water contents of 13％～35％．The maximal failure stress and strain were 3.9 MPa and 95％．respectively．At three typical environment conditions of RH=0.50％ and 100％

the influence of formamide and glycerol on the retrogradation of TPS was studied using X-ray diffractometry．It was found that compared to glycerol

formamide could effectively restrain the retmgradation at various humidities The property improvement of TPS by using formamide was ascribed to the formation of more stable hydrogen bonds between plasticizer molecules and the hydroxy groups of the starch．