Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 3

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: Kraft lignin

Sortuj według:

Ogranicz wyniki do:

Bio-based polyurethane applied as matrix of fiberglass reinforced composite

de Sousa Jr. R. R., Miranda E. A., Batalha G. F., dos Santos D. J.

Journal of Achievements in Materials and Manufacturing Engineering

2017

Vol. 81, nr 1

5--10

Purpose: of this paper was to develop and to characterize the mechanical behaviour of a structural composite obtained from a bio-based polyurethane matrix reinforced with fiberglass. Design/methodology/approach: Castor oil and Kraft lignin-containing polyol was applied for bio-based polyurethane synthesis. Structural composite was obtained by reinforcing this renewable source bio-based polymer with fiberglass mat. Polyester resin composite was also obtained for comparison, following the same process and reinforcement conditions. Mechanical characterization was carried out through uniaxial tensile, flexural strength, Izod impact tests and additionally scanning electron microscopy (MEV). Findings: Bio-based polyurethane composite was obtained and presented higher ultimate tensile strength (UTS) and equivalent impact resistance in comparison to polyester matrix composite. Research limitations/implications: Effects of Kraft lignin and fiberglass contents changing on mechanical properties might be investigated in future researches. Practical implications: Revalorization of Kraft lignin. 50 million tons of lignin are produced worldwide every year as by-product of pulp and paper manufacturing. The most part of this Kraft lignin is currently burned for energy generation. Originality/value: Results indicated the possibility of reusing this industrial wasted by-product at large scale as polymeric matrix for structural composite, in which high UTS and impact resistance are required.

Fire resistance of wood treated by emulsion from Kraft lignin

Dos Santos P., Da Silva S., Gatto D., Labidi L.

Drewno : prace naukowe, doniesienia, komunikaty

2016

vol. 59, nr 197

199--204

The use of wood for construction is not new, however, in some countries there are many resistances to its use, due mainly to the behaviour of wood during a fire. This study aimed to enhance the fire resistance of wood by treating the wood with Kraft lignin emulsion. An emulsion from Kraft lignin was used for the treatment of wood Pinus sp. by full cell methods. The specific mass, wettability and Brinell hardness were analysed. Fire resistances were determined (ignition, flame and ember time). The obtained results showed that the ignition times of treated wood, were higher than those of untreated wood. The emulsion hinders the ignition of samples in approximately 10 seconds. Conversely, the flame and ember time was significantly longer in wood treated, but there was a lower mass loss, compared to untreated wood. This shows that the treatment improves the behaviour of wood in relation to the ignition of fire and also increases the hardness of the wood. Wettability analysis was possible to observe that treatment reduces the rate of moisture uptake.

Preparation and characterisation of hydrated silica/lignin biocomposites

Klapiszewski Ł., Madrawska M., Jesionowski T.

Physicochemical Problems of Mineral Processing

2012

Vol. 48, iss. 2

463-473

Silica/lignin biocomposites were obtained by a new method proposed and fully characterised. Silica was precipitated from aqueous solution of sodium silicate (as an SiO2 precursor) and sulphuric acid (as a precipitating agent). The support obtained was subjected to surface functionalisation with aminosilane and then modified with Kraft lignin preliminary activated with sodium periodate solution. The products were characterised by elemental (N, C, H, S) and colorimetric analyses. Adsorption properties of the products were evaluated on the basis of determination of specific surface area, pore volume and pore diameter. The influence of the amount of lignin incorporated into the silica matrix on the physicochemical properties of the biocomposites was proved to be significant. The materials obtained can be used as selective adsorbents of heavy metals or pro-ecological polymer fillers.