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中文摘要：
合成了双（烷氧-亚胺芳氧）基钛（IV）配合物,通过IR,1H NMR和元素分析对其进行表征,X射线单晶衍射测定了其晶体结构.单晶结构分析表明,该晶体属于三斜晶系,空间群为P1^-,a=14.294（9）？,b=16.206（10）A,c=18.458（12）A,V=3911（4）A^3,Dc=1.098 g·cm^-3,μ=0.262 mm^-1,F（000）=1589,Z=2,R1=0.081,wR2=0.240.实验结果表明该配合物在130℃以上能引发D,L-丙交酯单体开环聚合,可得数均分子量（Mn）为8.8×10^4 g/mol的聚（D,L-乳酸）（PDLLA）.动力学研究表明该聚合反应对D,L-丙交酯单体浓度和催化剂浓度分别呈2级和1级,表观活化能和频率因子分别为76.63 kJ/mol和2.91×10^11.通过苄基封端聚合物1H NMR谱的研究,表明钛配合物引发D,L-丙交酯开环聚合是基于以Ti—O键为活性中心引发D,L-丙交酯单体酰氧键断裂开环聚合的＂配位-插入＂机理.
英文摘要：
A bis（alkoxy-imine-phenoxy） titanium（IV） complex was synthesized and characterized by IR,1H NMR,elemental analysis and single crystal X-ray diffraction method.The crystal of titanium（IV） complex belongs to triclinic system with space group,P,a=14.294（9）,b=16.206（10）,c=18.458（12）,V=3911（4） 3,Dc=1.098 gocm-3,μ=0.262 mm-1,F（000）=1589,Z=2,R1=0.081,wR2=0.240.The ring-opening polymerization（ROP） of D,L-lactide catalyzed by the titanium（IV） complex could take place over 130 ℃ and the maximum number-averaged molecular weight（Mn） of poly（D,L-lactic acid）（PDLLA） was 8.8×10^4 g/mol.Kinetics experiments indicate that the polymerization shows second-order kinetics in D,L-lactide monomer concentration and first-order kinetics in catalyst concentration.The apparent activation energy（Ea） and frequency factor（A） amount to 76.63 kJ/mol and 2.91×1011,respectively.1H NMR spec-troscopy of polymer terminated by benzyl group suggests that the polymerization proceeds via a conven-tional coordination-insertion mechanism and Ti-O active centers initiate the cleavage of acyl-oxygen bond of D,L-lactide monomer.
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