| Polylactide is a well-known and better biocompatible medical material. However, it has not good of the hydrophilicity and the controlled degradation. For this reason, PMLA and PEMLA, which were high hydrophilicity, flexibility and controllable degradation rate, were prepared from D,L-lactide, maleic anhydride and glycol. The characterizatio- ns of the synthesized polymers were by the means of multi-angle laser light scattering (MALLS), fourier transform infrared spectrometry (FTIR), nuclear magnetic resonance spectrometer (NMR), differential scanning calorimeter (DSC) and the classical chemical analysis to explore the structures and the properties. Thereafter, surface wettability, biodegradation of the synthetic materials was investigated. Moreover, LPEMLA and LPEMA-LA were synthesized for improving the property of polymer. The main works and conclusions are included as follows:(1) PMLA was synthesized by melt ring-opening polymerization of D,L-lactide and maleic anhydride. Then, an extensive investigation effort was expended in under- standing the effects of the Sn(Oct)2, p-toluene sulphonic acid and the time, and in exploring the structures and the properties.①FTIR, 13CNMR, 1HNMR and chemical analysis showed that PMLA was successfully prepared by copolymerizing of D,L-LA and maleic anhydride. Glass transition temperature (Tg) of PMLA determined by DSC was 50.9℃, which is lower than PDLLA.②1HNMR and chemical analysis showed that the content of the double bond in PMLA was 3.5%.③The results of orthogonal experimental design indicated that the optimized reactive condition of making the PEMA were: the p-toluene sulphonic acid added with 5% of LA in weight, the Sn(Oct)2 added with 1/7000 of LA in mol and the reaction last for 60h.(2) The preparation of PMLA by the condensation of maleic anhydride and glycol, using p-toluene sulphonic acid as a catalyst. Then, an extensive investigation effort was expended in understanding the effects of ratio of maleic anhydride and glycol, the time and the temperature, and in exploring the structures and the properties.①FTIR, 1HNMR showed that PEMA was successfully prepared by solution polymerization. ②When the ratio of maleic anhydride and glycol was 1:2, the utilization rate of the maleic anhydride reached to 86% in vacuum drying oven, the reactive temperature was 120℃.(3) A novel biodegradable polymer-PEMLA was synthesized by copolymerizing lactide and PEMA. Then, an extensive investigation effort was expended in understand- ing the effects of ratio of PEMA and lactide, the time, the temperature and the propotion of Sn(Oct)2.①FTIR, 1HNMR showed that PEMLA was successfully prepared by liquate copolymerization. Tg of the synthetic polymer determined by DSC was 41.3℃, which indicates that the flexibility of the polymer has enhanced.②The optimized reactive condition of making the PEMLA were: the ratio of PEMA and lactide was 1:5, the reactive temperature, time and the L/I were 145～150℃, 24 h and 3000, respectively.(4) The properties of PEMLA based substrate films were investigated, including surface wettability and biodegradation. The surface wettability evaluation was based on static water contact angle (sessile drop contact angle) and water adsorption ratio, while the actual degradation experimentation in vitro was used to estimate the biodegradation behavior. The results as follows:①The hydrophilicity and degradation rate of PEMLA increases with increase of the content of PEMA in PEMLA. Considerating the hydrophilicity and physical state, the PEMLA with PEMA 20% in weight is concluded to be the better polymer.②The degradation rate of PEMLA reaches to its maximum in the third week and in the sixth week. The degradation rate was in the sequence of PEMLA-3> PEMLA-1 and PEMLA-2.(5) The cross-linking of PEMA, PEMLA was initiated by the BPO, MMA. Then, an extensive investigation effort was expended in understanding the effects of the BPO, MMA and the time, temperature. The LPEMA-LA was polymerized by the condensati- on of LPEMA and D,L-LA.①1HNMR showed that LPEMA, LPEMA were successfully prepared by using radical polymerization .②The optimized reactive condition of making the LPEMA, were: BPO, MMA added with 6%( LPEMLA 3%) and 10% in weight, respectively, the temperature and time were 80℃and 8h, respectively.③The water hydrophilicity was in the sequence of PEMLA>LPEMLA, and LPE MA-LA is close to PEMLA.
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