Chemical transformations during mechanoactivation of ε‐polylysine‐poly‐L‐lactic acid mixture to obtain amphiphilic copolymers

Abstract

In this study presents a new strategy for the preparation of amphiphilic copolymers of ε‐polylysine (PL) and poly‐L‐lactic acid (PLA) using one‐step pulsed mechanochemical approach. Correlation between the synthesis parameters (ratio of homopolymers) and the structure of the resulting copolymers has been studied. The interaction products were characterized by nuclear magnetic resonance, Infrared spectroscopy, size‐exclusion chromatography, by varying the mass ratio of the initial homopolymers (PL:PLA = 10:90; 50:50; 90:10). It is shown that the largest number of product yield is formed in a ratio of homopolymers of 50:50, according to the reaction of aminolysis of polyesters. The dynamic light scattering method, transmission electron microscopy, and small‐angle x‐ray scattering were used to characterize nanoscale structures of copolymer macromolecules in aqueous solvent. As a result of pulsed mechanochemical action at all three ratios of homopolymers (PL:PLA = 10:90; 50:50; 90:10 w/w), the aminolysis reaction of the ester group occurs and branched macromolecules of copolymers are formed, which consist of chemically related sequences of homopolymers—main chain—PL, side branches—PLA. However, the maximum yield of the amphiphilic copolymer was 90 wt% with a PL:PLA ratio of 50:50. This study can serve as the development of important areas: deepen knowledge in the field of mechanochemical synthesis of amphiphilic copolymers.