论文部分内容阅读
A small molecule (GMS-SA2) with one alkyl chain and two terminal carboxyl groups was synthesized successfully by the reaction of glyceryl monostearate (GMS) with excess succinic anhydride (SA).Then,GMSSA2 was used as a coupling agent to condensate with polyethylene glycols (PEG) of different molecular weight or polyethylene glycol monomethyl ether (PEGm) in the presence of stannous octoate as catalyst and diphenyl ether as azeotropic agent.The AB2 star-shaped miktoarm copolymers were obtained successfully and were characterized by 1H-NMR,DSC,GPC,XRD,FTIR and polarizing microscopy.The results of DSC and XRD measurements indicate that the crystallization temperature and the melting temperature of the AB2 star-shaped miktoarm copolymers are different from those of the corresponding linear PEGs,because the existing of GMS-SA2 alters their crystalline growth velocity and the perfect degree of crystals.It is very important to control the crystal morphology of star-shaped copolymers by introducing the miktoarm into the starshaped polymers and adjusting its content in star-shaped polymers.