Nano-wollastonite to improve fire retardancy in medium-density fiberboard (MDF) made from wood fibers and camel-thorn

Abstract

ABSTRACT Wollastonite is an abundant mineral containing silicon, calcium and oxygen that has been shown to improve the properties of wood-based panels. Camel thorn (Alhagi maurorum) is a weed growing across much of Central Asia, and has relatively few commercial uses. The effects of addition of nano-wollastonite (NW) and camel-thorn chips on fire resistance of medium-density fiberboard (MDF) were assessed. Addition of 5 or 10% NW to urea-formaldehyde resin produced significant improvements in times to onset of ignition and glowing, as well as duration of burning in the panels. NW acted as a non-combustible mineral insulating layer. DFT analysis suggested that bonds between NW and wood cell-wall polymers improved overall panel properties by better integrating fibers into the composite matrix. The increased thermal conductivity caused by addition of NW also improved resin curing. Addition of 5 or 10% camel thorn chips to the resin prior to pressing negatively impacted fire properties. The results illustrate the potential for improving fire properties in MDF properties using NW.