A new copper complex, trans-diaqua-trans-bis [1-hydroxy-1,2-di (methoxycarbonyl) ethenato] copper (abbreviation Cu(II) complex), was synthesized and its plant growth regulation properties were investigated. The results show a sharp dependence of growth regulation activity of the Cu(II) complex on the type of culture and its concentration. New plant growth regulator accelerated the development of the corn root system (the increase in both length and weight) but showed a smaller effect on the development of the wheat and barley root systems. Stimulation of corn growth decreased with increasing Cu(II) complex concentration from 0.0001% to 0.01% (inhibition at high concentrations—0.01%). The development of corn stems was also accelerated but to a lesser extent. Chitosan-coated calcium alginate microcapsules suitable for delivery of Cu(II) complex to plants were prepared and characterized. Analysis of the FTIR spectrum showed that complex molecular interactions between functional groups of microcapsule constituents include mainly electrostatic interactions and hydrogen bonds. Microcapsules surface exhibits a soft granular surface structure with substructures consisting of abundant smaller particles with reduced surface roughness. Release profile analysis showed Fickian diffusion is the rate-controlling mechanism of Cu(II) complex releasing. The obtained results give new insights into the complexity of the interaction between the Cu(II) complex and microcapsule formulation constituents, which can be of great help in accelerating product development for the application in agriculture
Oriented strand board (OSB) is a commonly used structural wood-based panel for walls and roof siding, but recently the industry has become interested in OSB as a substrate for indoor and outdoor furniture. Particleboard is mainly used in furniture productions and has become popular as a construction material due to its numerous usage possibilities and inexpensive cost. Moisture is one of the most important factors affecting wood-based panel performance and the post-treatment conditions affected their affinity to water. When OSB and particleboard are used as substrates for coatings, their surface characteristics play an important role in determining the quality of the final product. Furthermore, roughness can significantly affect the interfacial phenomena such as adsorption, wetting, and adhesion which may have an impact on the coating performance. In this research particleboard and OSB panels were sanded, re-pressed and IR heated and the influence of surface treatments on hardness, roughness, wetting, water, and water vapour absorption was studied. Results showed that sanding improved the wetting of particleboard and OSB with water. Moreover, studied surface treatments increased water absorption and water penetration depth of OSB panels, and re-pressing had a positive effect on reducing the water vapour absorption of particleboard and OSB panels.
27 June 2019 in International Journal of Polymer Science
In the present study, the influence of adding natural fillers to a cellulose acetate (CA) matrix, in order to develop biocomposites, on the properties of the achieved materials has been investigated. Extracted wood flour, holocellulose, and alpha cellulose were used as appropriate fillers. The results of the thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) of the fillers and biocomposites suggested the importance of the degree of degradation of filler properties, induced by the chemical treatment necessary for the preparation of the fillers, with emphasis on the content of lignin and the degradation of cellulose. Scanning electron microscopy (SEM) and mechanical analysis revealed that the matrix-filler ratio had a major effect on the prepared CA-based biocomposites, since polarity differences between the two major components caused the reduction of attractive forces in the matrix-filler relation, subsequently altering the properties of the developed materials.
The modification of wood and its surface is one of the challenges that is being perfected with the aim of transitioning to sustainable management. This study investigated the dynamic mechanical and thermal behaviour of unmodified and styrene modified fir wood (Abies alba Mill.). Styrene monomer was chosen and impregnated into the porous structure of fir wood by reversible addition-fragmentation chain transfer (RAFT) polymerisation. Attenuated total reflection Fourier-transform infrared spectroscopy (FTIR-ATR), dynamic mechanical analysis (DMA), and thermogravimetric analysis (TGA) were employed to characterise the chemical structure, viscoelastic properties, and thermal stability of unmodified and modified (surface-modified) wood. All tests have to be regarded as being preliminary due to the small number of specimens. Fourier transform infrared analysis showed evidence of the phenyl group from styrene at 700 cm−1. DMA results showed that the modified wood caused an increase in the glass transition temperature relative to the unmodified wood. In addition, modification with styrene improves thermal stability, as revealed by thermogravimetric analysis (TGA).
The effect of temperature and moisture on the behaviour of solid wood is a well-known fact that directly affects wood creep as well. Wood creep includes three types of behaviour, such as viscoelastic creep, mechano-sorptive creep, and pseudo-creep and recovery. All these types can occur simultaneously, and it is sometimes complicated for researchers to isolate or distinct one from another. This paper presents a review of literature on wood rheology and creep properties, as well as factors that influence them, mainly time, temperature, and moisture content. The study of the viscoelasticity and wood creep is very important for gaining knowledge to be applied in solid wood bending.
The paper gives an overview of chemical changes during heat treatment of wood and their influence on environment. Wood is one of the most used building materials because of its physical and technological properties. Various procedures improve its pro...