Development of Materials Based on Poly(lactic acid) and Copper(II) Sulfate Impregnated by the Crazing Method

The common approach to creating antimicrobial polymer materials is the distribution of a bactericidal additive in a material by mixing the additive with a solution or a melt of the polymer. This work proposes the method introducing of copper(II) sulfate, which has antimicrobial properties, into a poly(lactic acid) film by forced impregnation of a salt solution via the crazing mechanism. CuSO4 has been found to be uniformly distributed in the bulk of the polymer in the form of particles with sizes of about 100 nm. In the course of the structural modification, the surface of the polymer film becomes rougher and more hydrophobic. The water contact angle increases from 40° to 60°–65°. The incorporation of CuSO4 does not affect the surface properties but has a reinforcing effect on the polymer matrix as is evident from tensile tests (strength and elongation at break increase by 2.5 and 1.4 times, respectively).