The influence of modified polyhexamethylene guanidine PHMG on the biodegradation of polylactide

The present study involved the addition of several potentially biocidal PHMG derivatives into polylactide (PLA) for the subsequent assessment of the changes in physical properties and properties important for the practical application of the prepared composites. In addition, biofilm formation on the surface of the PLA composites as well as their biodegradability were also evaluated. As can be seen from the results the addition of PHMG derivatives whose content did not exceed 0.6% in the polylactide matrix did not considerably affect the durability of the new composites, whereas water vapour permeability was significantly altered even with the content of 0.4% of PHMG derivatives in the polylactide matrix. Introducing PHMG stearate and PHMG granular polyethylene wax into PLA significantly decreased its biodegradability whereas introducing PHMG salt of sulfanilic acid had a positive effect on this process. The analysis of the surface of the PLA composites with the use of SEM method reveals that the introduction of PHMG stearate as well as PHMG granular polyethylene wax into PLA inhibited the biofilm formation.

► Composites have been the subject of increasing scientific interest. ► We have not found a description of a similar investigation in available literature. ► Polyethylene wax introduced into PLA significantly decreased its biodegradability. ► The introduction of stearate and PE wax PHMG into PLA inhibited the biofilm formation.