Experimental Evaluation of a New Giant Reed (Arundo Donax L.) Composite Using Citric Acid as a Natural Binder

Abstract

The raw materials used to manufacture thermal insulation in buildings consume a large amount of energy and are not generally biodegradable, which means it is necessary to increase the use of renewable, eco-friendly resources such as plant fibers in order to reduce the environmental problems this generates. The wood adhesives developed by the petrochemical industry offer excellent performance and are affordable. However, their use has an expiry date and in the future they will be rejected due to the environmental and health problems they can cause. The objective of this work was to develop a new eco-friendly biocomposite that could be used for thermal insulation in buildings. Boards were manufactured from giant reed particles with a particle size of 2 to 4 mm, using 5 and 10% by weight of citric acid as a natural binder. Experiments were then carried out to investigate the effect of board density on mechanical, physical, and thermal properties. A new type of composite was obtained with a thermal conductivity of 0.081-0.093 W/m K, which makes it suitable as an insulating material. The boards with a density of 850 kg/m 3 had a modulus of rupture (MOR) of 12.5 N/mm 2 , a modulus of elasticity (MOE) of 2440 N/mm 2 , and an internal bonding strength (IB) of 0.61 N/mm 2 , and they could be used as insulation panels for divisions and enclosures in buildings.life. When choosing a natural insulating material, several factors should be considered, such as its thermal performance, availability, cost, installation method and ecological impact.Studies have been carried out on the insulating properties of plant waste and fibers: coconut fiber [1], paper manufacturing waste and corn peel [2], kenaf fibers [3], cotton stalk fibers [4,5], coconut husk and bagasse [6], hemp fibers [7,8], date palm fibers and gypsum [9], flax [10], flax and hemp [11], rice straw [12], sisal [13], sugarcane bagasse [14], giant reed [15,16], Canary Islands palms [17], and Washingtonia palms [18].Giant reed (Arundo donax L.) was used as a building material in many Mediterranean countries. In the south of the province of Alicante it was used in all buildings up to the beginning of the 20th century, mainly forming part of the roof and floor. It continued to be used in small detached houses and farm buildings until the 1960s. More recently, it is no longer used, thus leading to excessive growth of this plant population along river banks. This poses a serious threat when the water level rises, as the reeds can be easily ripped up by the force of the waters and result in problems such as blockage of bridges and other infrastructures. Therefore, the use of giant reeds for industrial purposes would provide an environmental advantage.At present, most wood adhesives such as formaldehyde-based resins, vinyl acetate resins, and isocyanate-based resins are composed of different materials derived from fossil resources. Wood adhesives have been developed by the petrochemical industry and offer excellent performance, good working properties and are affordable. Howeve...

A Review on Citric Acid as Green Modifying Agent and Binder for Wood

“…However, higher density (800 kg/m 3 ) and resin content (20 wt %) are needed for CA-bonded particleboard to attain that comparable strength. It is noted that new giant reed particleboard (700 kg/m 3 ) bonded with 5 and 10 wt % CA has very low MOR and MOE as well as IB [72] compared to that of 10 wt % UF-bonded poplar particleboard with the same density [82]. Particleboard bonded with pMDI required a relatively lower resin content (8 wt %) to attain suffice strength performance, followed by PF which is 12 wt %.…”

“…However, at a pressing temperature of 180 • C, boards bonded with 12.5% CA and higher have surpassed the requirements stipulated in JIS A 5908 in terms of TS while boards bended with 100% maltodextrin failed to meet the requirement. Ferrandez-Garcia et al [72] fabricated particleboard from new giant reed (Arundo Donax L.) bonded with 10% CA. The results revealed that the produced particleboard is fit to be applied as insulating materials based on their good mechanical and thermal performance.…”

The Influence of Processing and Particle Size on Binderless Particleboards Made from Arundo donax L. Rhizome

“…In this regard, studies have been carried out on particleboards in which synthetic resins are replaced with natural resins and adhesives, such as protein, lignin, tannin, gluten, starch, citric acid, etc. [27][28][29][30][31][32][33].…”

Properties of Wood Particleboards Containing Giant Reed (Arundo donax L.) Particles

“…There are also studies on the use of giant reed (Arundo donax L.) in particleboards with different adhesives such as urea formaldehyde [19], starch [20] and citric acid [21].…”