Panels were made from Arundo donax L. particles bonded with different non-modified starches as adhesive without chemical additives by hotpressing at a low temperature (110 ºC) and pressure (2.6 N/mm 2 ). The experimental panels were tested for their physical and mechanical properties according to the procedures defined by the European Union (EN) Standard. The microstructure of samples was observed by scanning electron microscopy (SEM). Panels manufactured with potato starch had the highest modulus of rupture and modulus of elasticity, meeting the standard for load bearing (grade P4 for indoor use in dry ambient) (EN 312: 2003). Panels made with corn starch and wheat flour, at a 10% level and three pressing cycles met the standard for general uses (grade P1). Panel bonded with rye bran flour achieved the best internal bond strentgh. The water resistance was poor and needs to be improved.

No abstract

A large amount of research is being carried out to increase the use of renewable and eco-friendly resources like plant fibres for manufacturing new products in order to reduce energy consumption and improve their environmental impact. The almond is a deciduous tree that is native to Mediterranean areas, although nowadays the United States is the world’s main almond producer. The almond fruit has three distinct parts: the inner core or flesh, the hard middle part or shell, and the outer covering of the shell, called the hull (exocarp and mesocarp). This work analyses the use of almond residues for producing eco-friendly particleboards. The ground hull of the almond has been used as a raw material, obtaining 4 different particle sizes. Eight type of board has been manufactured without using any kind of adhesive. The particle size influences some physical and mechanical properties. With particle sizes <0.25 mm it is possible to achieve greater strength in terms of modulus of rupture (MOR): 14.01 N/mm2, modulus of elasticity (MOE): 2295.32 N/mm2 and internal bonding strength (IB): 0.57 N/mm2. This study shows that it is technically possible to manufacture boards with this material without using adhesives.

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...

This paper presents an experimental study on the bond behaviour of cement panels reinforced with plant fibres from the recycling of waste jute bags, using starch as a plasticiser. During processing, different proportions of jute (5 wt %, 10 wt %, 15 wt %, and 20 wt %) were used with respect to the weight of cement, and the mixture was exposed to a pressure of 2.6 MPa and a temperature of 100 °C. The density, swelling thickness, internal bonding, flexural strength, and thermal conductivity were studied. Mechanical tests indicated that the values of the modulus of rupture (MOR) and the modulus of elasticity (MOE) increased over time; thus, the jute particles appeared to be protected by the plasticised starch and no degradation was observed. At 28 days, the particleboard with 5% starch had an MOR of 12.82 MPa and an MOE of 3.43 GPa; these values decreased when the jute proportion was higher. The thermal conductivity varied from 0.068 to 0.085 W·m−1·K−1. The main conclusion is that jute-cement-starch composite panels can be manufactured with physical, mechanical, and thermal properties that meet the European standards for use in the construction of buildings as partitions, interior divisions, and thermal insulators.