Preparation and characterization of poly(D,L-lactide-co-ethylene methyl phosphate)

✍ Scribed by Wen, Jie; Zhuo, Ren-Xi

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 214 KB
• Volume: 47
• Category: Article
• ISSN: 0959-8103
• DOI: 10.1002/(sici)1097-0126(199812)47:4<503::aid-pi90>3.0.co;2-n

✦ Synopsis

Poly(D,L-lactide-co-ethylene methyl phosphate) was synthesized by ring-opening polymerization of D,L-lactide (D,L-LA) and ethylene methyl phosphate (EMP) in bulk with as initiator. The inÑuence of reaction condi-Al(OiPr) 3 tions such as polymerization time, polymerization temperature and initiator concentration on the yield and molecular weight were investigated. The reactivity ratios of the two monomers were determined by the method. The KelenÈTu d°s homogeneous phase of the copolymer was conÐrmed by di †erential scanning calorimetry (DSC), wide-angle X-ray di †raction (WAXD) and scanning electron microscopy (SEM). DSC data showed that the glass transition temperature of the copolymers increased with the increase of their LA content, which is in agreement with the Fox equation. Water absorption at room temperature was used to evaluate the hydrophilicity of the copolymers. As expected, the hydrophilicity of the copolymer increased with the increase of EMP fraction therein. Copolymer hydrolysis was carried out in in the presence of triÑuoroacetic DMSO-d 6 /D 2 O, acid ; it was monitored by 1H NMR, the data suggesting that side-chain cleavage proceeded faster than main-chain cleavage, and the hydrolysis of the main chain was faster than that of poly(D,L-lactide). These materials show potential use in drug delivery systems.