Bilayer biocomposites based on coated cellulose paperboard with biodegradable films

R. RICCI; M. CABEZA; D.A.DAMICO; I. T. SEOANE; V. P. CYRAS; L.B. MANFREDI

Mar del Plata

Simposio; XVI Simposio Latinoamericano de Polímeros (SLAP 2018) y el XIV Congreso Iberoamericano de Polímeros (CIP 2018).; 2018

INTEMA

The development of biodegradable polymeric systems is increasingly in focus because sustainable solutions are needed to our future needs for energy and materials. Paper is widely used in packaging applications, because of its biobased, biodegradable and recyclable features. Water vapor barrier properties of paper are limited due to its hydrophilic nature so, polyolefins are generally chosen as coating materials to overcome its porosity and hygroscopicity. In this context, biopolymers with adequate barrier properties such as polyhydroxybutyrate (PHB), appear as a suitable choice to obtain paper-based renewable packaging. PHB is a biodegradable polymer that can be biosynthesized by a variety of bacteria, highly crystalline and hydrophobic, possessing intrinsic barrier properties. However, PHB presents some drawbacks such as high cost, slow crystallization rate, fragility and a narrow window for processing conditions. Plasticizer might be necessary in order to realize PHB polymeric films with adequate deformability. An emerging field deals with renewable nanofillers from cellulose. Particularly, PHB/cellulose nanocrystal (CNC) composites could also reduce additive migration to the food material in food packaging applications at low loadings, indicating that this material presents operational stability and can be used for products with long-term storage at room temperature. It is well known that the performance of bilayer composites is largely influenced by the adhesion between layers. In this case, the interfacial interaction between PHB and cellulose paperboard is poor due to the different nature of both components. Then, the incorporation of CNC could improve the compatibility between them. The aim of the present research is to obtain PHB/paperboard bilayer composites by compression molding and to evaluate the overall impact of using a PHB-based coating on paperboard properties. The effect of Tributyrin (TB) and CNC addition in the PHB layer was also evaluated.