Impregnation of kraft paper support with polylactic acid multilayers

Abstract

PLA coating on Kraft paper is very promising systems for food packaging, and has potential environmental advantages over conventional synthetic paper coatings. This work was focused on: (i) analyzing the physicochemical, thermal and microstructural properties of PLA films; (ii) developing and studying multilayer systems obtained by impregnation of Kraft paper with different layers of PLA solution; (iii) evaluating the influence of PLA layers on the support cellulosic properties. The PLA coating improves packaging material performance and hence the functional properties of Kraft paper. The impregnation of hygroscopic materials as the Kraft paper with PLA was an alternative interesting to obtain more hydrophobic matrices. The assembled materials attained were heat-sealed. Furthermore, the use of PLA adds to potential food applications, a renewable resource value obtained from sources agricultural. The design of this multilayer support also allows its extension to other media such as paperboard. Moreover, the addition of 4 or 5 layers favourably modified the assembled system properties. Increasing even further the number of PLA layers, system properties hardly underwent a significant improvement. Consequently, the selection of the number of PLA layers would be a response to a relationship of commitment between the increase in the cost and the enhancement of the properties.