含氨基酸侧链的两性聚合物P(εACRLLY-co-AM)的合成和性能表征

Synthesis and Characterization of an Amino Acid Side Chain Containing Ampholytic Polymer P(εACRLLY-co-AM)

利用L-赖氨酸上的ε氨基与丙烯酰氯反应,合成了一种包含完整氨基酸单元的两性单体(εACRLLY),并用1H-NMR、FT-IR、元素分析对该单体进行了表征;将该单体与丙烯酰胺共聚制备了一种具有完整氨基酸侧链的p H敏感的两性聚合物P(εACRLLY-co-AM)。通过研究聚合物溶液表观黏度与p H值、外加盐浓度间的关系,聚合物在溶液中的流体力学直径与溶液p H值间的关系,发现该聚合物表现出显著的p H敏感性,具有明显的两性特征和反聚电解质效应,聚合物的等电点为p H 6.2;聚合物中氨基和羧基在不同p H值下具有不同的电离状态是造成这一性能变化的主要原因。

An ampholytic monomer containing full amino acid units（ε-acryloyl L-lysine（εACRLLY）） was synthesized as a reaction product of acryloyl chloride and ε-amino of L-lysine. Its structure was characterized by 1H-NMR, FTIR and elemental analysis. A p H-sensitive ampholytic copolymer P（εACRLLY-co-AM） containing full amino acid side chains was prepared by polymerization of εACRLLY and acrylamide（AM） through free radical polymerization. The isoelectric point of P（εACRLLY-co-AM） is 6.2.The changes of the apparent viscosity of the polymer solution with p H and salts concentration, and the change of hydrodynamic diameter at different p H indicate that this polymer is p H-sensitive and has ampholytic and anti-polyelectrolyte effects. These properties are related to the dissociation difference of carboxyl and amino groups on P（εACRLLY-co-AM） molecular chains at different p H values.