Doubly degradable dynamers: dynamic covalent polymers based on reversible imine connections and biodegradable polyester units
作者:Kazuyuki Fukuda、Manabu Shimoda、Makoto Sukegawa、Tadahito Nobori、Jean-Marie Lehn
DOI:10.1039/c2gc35875a
日期:——
We report the preparation and features of environmentally friendly “Green Dynamers” (GDs), dynamic polymers presenting sequential double-degradation features, chemical and biological. They were obtained by connecting biodegradable oligomers (such as small units of polybutylene adipate, PBA, and polybutylene succinate, PBS) through chemically degradable reversible imine bonds. The GDs possess water disintegratability, mendability and biodegradability. Their degradation rate may be modulated through and increases with the number of imine groups in the polymeric chain. The GDs were thermodynamically stable and maintained their molecular weight and their mechanical strength in air. However, when they were contacted with water, the imine bonds easily hydrolyzed, breaking up the polymer chains into oligomers. After such water disintegration, the residual oligomers were biodegraded into CO2 and water. In addition, the imine bonds were restored by evaporation of the water, leading to recovery of the molecular weight and of the mechanical properties of the GDs. The present GDs may be considered to represent a class of doubly-degradable polymers, combining chemical and biological degradability features, that operate in mild environmental conditions. This concept may contribute to solve the problem of waste elimination associated with the use of non-degradable polymeric materials.
我们报道了环境友好型“绿色动态聚合物”(Green Dynamers,简称GDs)的制备及其特性。这些动态聚合物具有顺序双降解特征,即化学降解和生物降解。它们通过化学可降解的可逆亚胺键将生物可降解的低聚物(如聚丁二酸丁二醇酯的小单元PBA和聚丁二酸丁二醇酯的小单元PBS)连接而成。GDs具有水解分散性、自修复性和生物降解性。其降解速率可通过聚合物链中的亚胺基团的数量调节,并随着亚胺基团数量的增加而增加。GDs在热力学上是稳定的,在空气中保持其分子量和机械强度。然而,当它们与水接触时,亚胺键容易水解,使聚合物链断裂成低聚物。经过这种水解分散后,残余的低聚物被生物降解成CO2和水。此外,亚胺键在水蒸发后得以恢复,导致GDs的分子量和机械性能得以恢复。目前的GDs可视为一类双重降解聚合物,结合了化学和生物降解特性,在温和的环境条件下运作。这一概念有助于解决与不可降解聚合物材料使用相关的废物消除问题。