Functionalized cork-polymer composites (CPC) by reactive extrusion using suberin and lignin from cork as coupling agents

• Published in: Composites. Part B, Engineering Vol. 67; pp. 371 - 380
• Main Authors: Fernandes, Emanuel M., Aroso, Ivo M., Mano, João F., Covas, José A., Reis, Rui L.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.12.2014; Elsevier
• Subjects: A. Polymer–matrix composites (PMCs); Applied sciences; B. Fibre/matrix bond; Benzoyl peroxide; Composites; Cork; Coupling agent; Coupling agents; D. Electron microscopy; E. Extrusion; Exact sciences and technology; Forms of application and semi-finished materials; High density; Mechanical properties; Plasticizers; Polyethylenes; Polymer industry, paints, wood; Polymer matrix composites; Technology of polymers; A. Polymer–matrix composites (PMCs); E. Extrusion; B. Fibre/matrix bond; D. Electron microscopy; Coupling agent; Lignin; Strengthening; Size stability; High density ethylene polymer; Lipids; Dispersion reinforced material; Composite material; Thermal stability; Additive; Olefin polymer; Elastic modulus; Cork; Double screw extruder; Mechanical properties; Antioxidant; Experimental study; Functional polymer; Thermal properties; A. Polymer-matrix composites (PMCs); Plasticizer; Stabilizer agent; Morphology; Concentration effect
• ISSN: 1359-8368; 1879-1069
• DOI: 10.1016/j.compositesb.2014.07.028

High density polyethylene (HDPE) and cork powder were compounded in a co-rotating twin-screw extruder to obtain cork-polymer composites (CPC) with improved properties. Benzoyl peroxide (BPO) was used as initiator agent, and suberin or lignin isolated from cork enhanced filler-matrix bonding and promoted mechanical reinforcement with environmental benefits. The novel composites were characterised in terms of dimensional stability, evolution of morphology, thermal and mechanical properties and their performance was compared with that of composites containing polyethylene-grafted maleic anhydride (PE-g-MA) as coupling agent. As expected, composites with coupling agent present higher mechanical properties, lower water uptake and thickness swelling variation. Suberin acts as plasticizer with antioxidant benefits, while lignin works as a coupling agent, improving tensile modulus and maximum strength. Increasing lignin content does not improve the mechanical properties but improves thermal stability.