Papers by Keyword: Cellulosic Fibre

Abstract: This paper shows the results of the mechanical characterisation of a series of new sustainable polymeric formulations filled with almond shell and cellulosic fibres for its use in rotomoulding process. Up to ten formulations of polyethylene and polycaprolactone, were developed with a content from 10 to 40 wt% of natural filler. The addition of these fillers decreased the mechanical properties, mainly when the formulation was carried out by physical mixing. However, good interfacial interaction between the polymer and filler was produced in the compounding process, obtaining final formulations appropriated for rotomoulding.

Abstract: The extrusion process can produce composites with high-density matrix and fibre packing, low permeability and fibre matrix bond strengthening. This process is also compatible with the use of vegetable fibres as raw materials in the production of cost-effective construction elements such as ceiling panels. Sugar cane bagasse fibres (SCF), one of the largest cellulosic agroindustrial by-products of sugar and alcohol industry available in Brazil, are a renewable resource usually used as a biomass fuel for the boilers. The remaining bagasse is still a source of contamination to the environment, so there is a great interest on exploiting novel applications to sugar cane bagasse fibres. In this work, the effect of SCF on extruded cementitious composite performance was evaluated. Three different contents of SCF were considered, using cellulose pulp as secondary micro-reinforcement to improve the resistance to the appearance of microcracks. Composites were prepared using a laboratory Auger extruder with vacuum chamber and were tested after 28 days of water curing and after 200 accelerated ageing cycles. Modulus of rupture (MOR) and Tenacity (TE) of extruded composites were assessed by four point bending test. Water absorption and apparent volume were determined by water immersion. Microstructure behavior was evaluated by mercury intrusion porosimetry and scanning electron microscopy (SEM). Results indicated that the introduction of larger fibres increased tenacity (TE) at 28 days and favored a higher amount of macropores (0.1 to 1 mm); SEM observations confirmed that fibre degradation occurred after 200 cycles.

Abstract: The preparation and characterization of cellulosic fibre-reinforced polypropylene composite foams is presented. The cellulose fibres were isolated from a barley straw obtained from local sources. They were compounded with the polymer in the melt state to obtain composites with nominal concentrations of 10 and 20% by weight. After compression-moulding the composite samples were foamed in a high-pressure batch-process employing CO2 as foaming agent. The effects of the fibre loading on the basics characteristics of the foams was investigated.

Abstract: Zeolites with different sizes and structures were applied on the surface of cellulose fibers with organic and inorganic binders. The effects of zeolite structure and size and choice of binder on the deodorization rate have been studied. The smaller the particle size, the more effective the deodorization rate of both the zeolite coated cellulose fibers and the powder itself. The deodorization rate depends on both the type and amount of inorganic binder. A silica based inorganic binder revealed higher efficiency on deodorization than silicate based inorganic binder and also higher than organic binders.

Abstract: The determination of electrokinetic properties such as the zeta-potential of polymer samples with classical methods is laborious and time-consuming. For this reasons, a reliable, fast, and easy to use measurement system based on streaming potential measurement was developed. In this novel measurement system, streaming potential is created by an oscillating flow of a small amount of electrolyte solution through the sample media. In addition, this setup allows direct titration and therefore time-resolved monitoring of changes in zeta-potential in a seconds timescale. With this instrument, the concentration- as well as the time-dependent adsorption behaviour of various non-ionic, anionic and cationic surfactants on a novel, regenerated cellulosic polymer was investigated. This new cellulose-based, fibrous textile polymer is permanently cationised, not only at the surface but throughout the whole fibre. The results show that even very low concentrations of surfactant, due to its charge and chemical composition, highly influence the surface charge of the polymer in a large range. Furthermore, the results for this new textile material are compared with other textile fibres, e. g. wool.