聚对苯二甲酸丁二酯-聚四亚甲基醚多嵌段共聚物的研究

合成了硬段含量和软段分子量不同的聚对苯二甲酸丁二酯-聚四亚甲基醚(PBT-PTMG)多嵌段共聚物。研究了硬段含量和软段分子量对嵌段共聚合过程的影响。当软段分子量较大、硬段含量较高时,在嵌段共缩聚过程中有均聚物伴生。当软段分子量在2000左右,硬段含量在20％左右时,基本上不生成均聚物。硬段重量含量为 20％的低硬段 PBT-PTMG多嵌段共聚物是结晶的。由它纺成的弹体纤维有良好的力学性能和弹性回复。热处理能改进纤维的弹性回复。     

具有血液相容性的嵌段聚酯-聚醚接枝共聚物的合成

本文研究了嵌段聚酯-聚醚膜经紫外光活化后,于水溶液中铈盐引发亲水性单体丙烯酰胺在其表面上接枝共聚合反应。同时对接枝物进行了证实和表征。并通过活体动物血液灌流实验表明,此接枝共聚物具有良好的血液相容性。     

HELIX SENSE-SELECTIVE COPOLYMERIZATION OF TRIPHENYLMETHYL METHACRYLATE WITH CHIRAL ANIONIC INITIATORS

Optically active copolymers of pairs of three monomers, triphenyl (methyl methacrylate)and one or two pyridyl substituted methyl methacrylate homologues, were obtained by helix-sense-selective copolymerization using complexes of organolithium with chiral ligand as anionicinitiators in toluene at low temperature. The copolymers obtained with (-)-sparteine (Sp) and(S,S)-(+)-and (R, R)-(-)-2, 3-dimethoxy-1, 4-bis (dimethylamino) butanes((+)-and (-)-DDB) complexes of organolithium showed low optical activity, but PMP complex with N, N-diphenylethyleneamine monolithium amide (PMP-DPEDA-Li) was effective in synthesizingcopolymers of high optical rotation ([α]_D~(25) about+320～1370°)which were comparable to thoseof relative homopolymers with one-handed helical structure.     

“Living”/controlled radical copolymerization of N-phenylmaleimide and styrene using Fréchet-type dendritic initiators

Polyarylether dendrons as macroinitiators for the "living"/controlled free radical copoly-merization of N-phenylmaleimide (PhMI) and styrene (St) have been demonstrated. The copoly-merization was carried out in bulk or anisole with CuBr/bipy catalyst at 100-130℃. It is found that the resulting copolymers possess predetermined molecular weights and narrower polydispersities (1.18 < Mw/Mn<1.32). The effects of reaction temperature and monomer feed on the copolymeri-zation kinetics were investigated in detail. By using the Fineman-Ross method, the apparent monomer reactivity ratios for the atom transfer radical copolymerization of PhMI and St were determined to be rphM1 = 0.0207, and rst = 0.0484, respectively.     

STEREOREGULARITY OF POLY (METHYL METHACRYLATE) OBTAINED WITH CHIRAL ANIONIC COMPLEX INITIATOR

The stereoregular polymerization of methyl methacrylate (MMA) have been investigatedwith chiral anionic complex initiator[FILi-(-)SP]in toluene, THF and toluene/THF [1/1(v/v)]. The tacticities of PMMAs obtained in the three solvents have been found to be mainly asyndiotactic triads(s-PMMA)with content of 72.3, 67.7 and 71.4%,respectively.