Bilayer biocomposites based on coated cellulose paperboard with biodegradable films

RICCI, ROCÍO; CABEZA, MACARENA; D'AMICO DAVID ALBERTO; SEOANE, IRENE; CYRAS, VIVIANA P.; MANFREDI, L.B.

Simposio; Simposio Latinoamericano de Polímeros; 2018

The development of biodegradable polymeric systemsis increasingly in focus because sustainable solutionsare needed to our future needs for energy andmaterials 1 .Paper is widely used in packaging applications, becauseof its biobased, biodegradable and recyclable features.Water vapor barrier properties of paper are limiteddue to its hydrophilic nature so, polyolefins aregenerally chosen as coating materials to overcome itsporosity and hygroscopicity 2 . In this context,biopolymers with adequate barrier properties such aspolyhydroxybutyrate (PHB), appear as a suitable choiceto obtain paper-based renewable packaging. PHB is abiodegradable polymer that can be biosynthesized by avariety of bacteria, highly crystalline and hydrophobic,possessing intrinsic barrier properties. However, PHBpresents some drawbacks such as high cost, slowcrystallization rate, fragility and a narrow window forprocessing conditions 3 . Plasticizer might be necessaryin order to realize PHB polymeric films with adequatedeformability. An emerging field deals with renewablenanofillers from cellulose. Particularly, PHB/cellulosenanocrystal (CNC) composites could also reduceadditive migration to the food material in foodpackaging applications at low loadings, indicating thatthis material presents operational stability and can beused for products with long-term storage at roomtemperature. It is well known that the performance ofbilayer composites is largely influenced by theadhesion between layers. In this case, the interfacialinteraction between PHB and cellulose paperboard ispoor due to the different nature of both components.Then, the incorporation of CNC could improve thecompatibility between them.The aim of the present research is to obtainPHB/paperboard bilayer composites by compressionmolding and to evaluate the overall impact of using aPHB-based coating on paperboard properties. Theeffect of Tributyrin (TB) and CNC addition in the PHBlayer was also evaluated