Flame resistant green wood nanocomposite
doi:10.1038/nindia.2016.103 Published online 12 August 2016
By using multiwalled carbon nanotubes, starch and softwood, researchers have synthesized a green wood nanocomposite that is thermally stable and flame retardant, making it potentially useful for home and industrial applications1.
Wood polymer composites made from petroleum-based polymers and solvents are not biodegradable and could pollute the environment. To prepare an ecofriendly wood nanocomposite, the researchers mixed modified multiwalled carbon nanotubes with starch, the softwood Kalmou (Ipomoea carnea) and water.
The carbon nanotubes significantly enhanced the wood nanocomposite’s mechanical properties, such as its tensile strength and hardness. The wood nanocomposite attained such mechanical properties due to the formation of strong chemical bonds between surface hydroxyl groups of the carbon nanotubes and methyl groups in the softwood.
The wood nanocomposite contained a continuous network that formed a protective layer and improved its flame-retardant property. The nanotubes also enhanced the interfacial adhesion between the components, slowing the combustion of the nanocomposite.
The nanotubes filled the voids in the nanocomposite, preventing water from penetrating deep into the wood nanocomposite and making the nanocomposite water resistant. Adding 0.5 parts per hundred modified carbon nanotubes to the wood nanocomposite remarkably improved its thermal stability, water resistance and flammability, the researchers say.
1. Baishya, P. et al. Functionalization of MWCNT and their application in properties development of green wood nanocomposite. Carbohydr. Polymer 149, 332-349 (2016)