PtBMA-b-P4VP的ATRP合成及其化学转变

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

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1．8×10^2～6．4×10^2的聚甲基丙烯酸叔丁酯（PtBMA—CD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（Me5[14]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（^1 H—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。

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 × 10^2 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 （Me6 [-14-]aneN4） 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, nu- clear magnetic resonance （1 H-NMR） and gel permeation chromatography （GPC）. Furthermore, the quat- ernization 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 ^1 H-NMR and FT-IR.