Tunable pH- and CO2-Responsive Sulfonamide-Containing Polymers by RAFT Polymerization
Tunable pH- and CO2-Responsive Sulfonamide-Containing Polymers by RAFT Polymerization
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DOI：
10.1021/acs.macromol.5b01453
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发表时间：
2015-08-25
期刊：
影响因子：
5.5
通讯作者：
McCormick, Charles L.
中科院分区：
文献类型：
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作者：
Abel, Brooks A.;Sims, Michael B.;McCormick, Charles L.
报道了pH和CO2响应的甲基丙烯酰磺酰胺（MSA）的受控RAFT聚合，所述MSA具有生物相关范围（pH = 4.5-7.4）中的pK（a）值。初始聚合在70 ° C下在DMF中用4-氰基-4-（乙基硫烷基硫代羰基硫烷基）戊酸（CEP）或4-氰基戊酸二硫代苯甲酸酯（CTP）进行，得到宽分子量分布的聚合物（K-w/M-n > 1.20）。同样，聚（甲基丙烯酰基磺酰乙酰胺）（pSAC）大分子CTA在70 ° C下的扩链是不成功的，表明在聚合过程中“活性”链端的损失。然而，通过在30 ℃下用2，2 ′-偶氮双（4-甲氧基-2，4-二甲基戊腈）进行MSA的RAFT聚合，获得了具有窄分子量分布（M-w/M-n < 1.15）和改进的链端保留的聚合物。合成每种MSA衍生物的均聚物，并在这些研究期间测定磺酰胺R基团对单体pK（a）和pH依赖性聚合物溶解度的影响。这些受控聚（MSA）可以通过低温RAFT制备而不需要官能团保护的设施，以及由此产生的pK（a）依赖性pH和CO2响应特性，在包括药物和基因递送和环境修复在内的领域中具有显着的潜力。
The controlled RAFT polymerization of a library of pH- and CO2-responsive methacryloyl sulfonamides (MSAs) that possess pK(a) values in the biologically relevant regime (pH = 4.5-7.4) is reported. Initial polymerizations were conducted at 70 degrees C in DMF with 4-cyano-4-(ethylsulfanylthiocarbonylsulfanyl)pentanoic acid (CEP) or 4-cyanopentanoic acid dithiobenzoate (CTP), resulting in polymers of broad molecular weight distributions (K-w/M-n > 1.20). As well, chain extension of a poly(methacryloyl sulfacetamide) (pSAC) macro-CTA at 70 degrees C was unsuccessful, indicating a loss of "living" chain ends during polymerization. However, by conducting the RAFT polymerization of MSAs at 30 degrees C with 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), polymers with narrow molecular weight distributions (M-w/M-n < 1.15) and improved chain end retention were obtained. Homopolymers of each MSA derivative were synthesized, and the influence of the sulfonamide R group on monomer pK(a) and pH-dependent polymer solubility was determined during these studies. The facility by which these controlled poly(MSAs) can be prepared via low-temperature RAFT without the need for functional group protection and the resulting pK(a)-dependent pH- and CO2-responsive properties point to significant potential in areas including drug and gene delivery and environmental remediation.