Synthesis And Characterization Of Morpholine-2,5-dione And Its Copolymers

This paper mainly focuses on the preparation process of two differentmorpholine-2,5-dione derivatives, as well as the synthesis of its polymers. Firstlyusing alanine or leucine to prepare the3(S)-methyl-morpholine-2,5-dione (MMD) or3(S)-isobutyl-morpholine-2,5-dione (IBMD) monomer and then optimizing thisprocess, Secondly, using malic acid (MLA) to initiate the ring-opening reaction ofMMD and-caprolactone (CL) to prepare a series of random copolymers. Finally,Amino-terminated polyethylene glycol monomethyl ether (Amino-MPEG) as thehydrophilic segment was grafted onto the prepolymers to synthesize the amphiphilicstar-shaped polymers.Alanine or leucine was used to react with chloroacetyl chloride to form theintermediate of morpholine-2,5-dione, followed by a sublimation method to obtain thefinal product. And then using melting point, FT-IR and1H-NMR to verify themonomer, meanwhile the impacts of the addition of Sb2O3, the temperature andvacuum to the product yield were studied and discussed, which was helpful tooptimize sublimation process conditions.Stannous octoate was used as the catalyst and MLA as the initiator to initiate thering-opening polymerization of CL and MMD, which formed a series of randomcopolymers with a pair of telechelic carboxyl groups at one end. These copolymerswere characterized by FT-IR,1H-NMR, acid number titration, gel permeationchromatography, the water contact angle, water absorption experiment anddegradation experiments, the results indicated that after being modified by MMD, thehydrophilic properties and biodegradable ability of the copolymer material wereimproved with the increase of the content of MMD in the copolymer.Furthermore, the Amino-MPEG was grafted onto these copolymers in a molarratio of2:1to synthesize a kind of novel amphiphilic star-shaped polymers, and thenforming the polymer nanoparticles respectively. At the same time, FT-IR,1H-NMR,water contact angle, water absorption experiments and degradation test wereconducted to characterize the properites of the star-shaped polymers, the resultsshowed that the hydrophilic properties and degradation performance of thestar-shaped polymer were remarkably improved. By the detection of the nanoparticle size analyzer and TEM, it was showed that the obtained amphiphilic star polymerscan self-assemble to form the nanoparticles in water, which have a potential medicalvalue.