PtBMA-b-P4VP的ATRP合成及其化学转变

以α-氯代丙酸乙酯(ECP)为引发剂,N,N,N′,N″,N″-五甲基二亚乙基三胺(PMDE-TA)为配体,在N,N′-二甲基甲酰胺(DMF)溶液中引发甲基丙烯酸叔丁酯(tBMA)进行原子转移自由基聚合(ATRP),调节聚合反应时间得到了端基为氯原子,数均分子量为1.8×103~6.4×103的聚甲基丙烯酸叔丁酯(PtBMA-Cl)大分子引发剂。采用合成的5,5,7,12,12,14-六甲基-1,4,8,11-四氮杂环化合物(Me614]aneN4)为配体,使PtBMA-Cl引发4-乙烯吡啶(4VP)进行ATRP反应,得到了PtBMA-b-P4VP两嵌段共聚物,可使P4VP的收率达到60%。通过对PtBMA-b-P4VP的不同链段进行季铵化和水解反应,得到了聚甲基丙烯酸-b-季铵化聚4-乙烯吡啶(PMAA-b-QPVPB)亲水性嵌段共聚物。傅里叶变换红外光谱(FT-IR)、核磁共振(1H-NMR)和凝胶渗透色谱(GPC)分析表明:所得嵌段共聚物的结构明确,可将PtBMA与P4VP的链段长度之比调整在1∶0.5~1∶1的范围内。

Synthesis and Chemical Transformation of PtBMA-b-P4VP by Atom Transfer Radical Polymerization

Atom transfer radical polymerization (ATRP) of tert-butylmethacrylate (tBMA) was studied using ethyl-2-chloropropionate (ECP) as initiator in DMF. The number-average molecular weight of the PtBMA-C1 with a chlorine end group (PtBMA-C1) can be controlled from 1.8 × 10~3 to 6.4 × 10~3 by adjusting the polymerization time. Poly (tert-butylmethacrylate)-b-poly (4-vinylpyridine) (PtBMA-b-P4VP) was prepared by ATRP using PtBMA-C1 as macroinitiator, CuC1 and 5, 5, 7, 12, 12,14-hexamethyl-1,4,8,11-tetraazamacrocyclotetradecane (Me_6 14] aneN_4 ) as catalyst and ligand. In this case, the yield of P4VP can be up to 60%. Structure and number-average molecular weight of PtBMA-C1 and PtBMA-b-P4VP were characterized by means of Fourier transform infrared(FT-IR) spectroscopy, nuclear magnetic resonance (~1H-NMR) and gel permeation chromatography (GPC). Furthermore, the quaternization of the synthesized diblock copolymer were finished at first. The quaternizated diblock copolymer was then hydrolyzed under room temperature to form hydrophilic PMAA-b-QPVPB diblock copolymer. The results show that the chain lenth ratio of PtBMA with P4VP can be adjusted in rage of 1 : 0.5-1 : 1 in ATRP process. The structure of black copolymers was clear based on the analysis of ~1H-NMR and FT-IR.