Effects of chemical treatments on hemp fibre structure

Development of Entada Mannii Fiber Polypropylene Matrix Composites for Light Weight Applications

“…Beckerman and Pickering, [7] reported that, untreated fiber degrades at lower temperatures due to the presence of thermally unstable fiber constituents such as hemicelluloses and pectins, whereas the alkali treated fiber is more thermally stable due to the removal of these constituents with temperatures increase. It is also reported that, thermal decomposition process mainly occurred on cellulose which in turn increase the overall degradation temperature of treated fiber [1,19]. sample weights.…”

“…A slight increase in temperature was also observed between 300-370 o C as a result of exothermic combustion. The untreated fiber degraded at lower temperature between 200-300 o C and became thermally unstable due to the presence of these fiber constituents lignin and hemicellulose [1,18]. Beckerman and Pickering, [7] reported that, untreated fiber degrades at lower temperatures due to the presence of thermally unstable fiber constituents such as hemicelluloses and pectins, whereas the alkali treated fiber is more thermally stable due to the removal of these constituents with temperatures increase.…”

“…Natural fibers such as bamboo, coir, jute, flax, sun hemp, ramie, kenaf, rice husk, sugar cane, pineapple among others have been investigated with RESEARCH encouraging results [1][2][3]. They have properties such as low cost, low density, readily available with good dimensional stability [1,4,5]. They are used in various engineering applications such as constructions and automobile industries.…”

Propriedades térmicas e mecânicas dos compósitos de Polipropileno pós-consumo reforçados com fibras de celulose

“…Na Tabela 3, são apresentados os valores do grau de cristalinidade (χ c ) e da temperatura de fusão cristalina (T m ) dos compósitos produzidos. Observou-se um decréscimo do grau de cristalinidade com a inserção das fibras de celulose para ambos os compósitos, que ocorre devido à falta de tratamento da fibra [23] utilizada, já que, com o tratamento, há um redução da região amorfa e por consequência,o aumento na cristalinidade dos compósitos [24] . O decrescimo na cristalinidade do PPR puro quando comparada ao PPV também puro, se deve a presença da segunda fase, o poliestireno, e ao tipo de processamento na qual os copos descartáveis foram submetidos [17] .…”

Creep behaviour of injection-moulded basalt fibre reinforced poly(lactic acid) composites

“…Further drawbacks are the significant water uptake, lower mechanical properties compared to synthetic fibres, and the susceptibility to thermal degradation. 18 Accordingly, the biocomposites with higher mechanical properties are often achieved with pulltrusion 10 or film stacking 11,12 methods to keep the extent of degradation of the fibres low and the fibre ratio as well as the length of the fibres ratio high. At the same time, the high cycle time method of filmstacking is not always suitable to commercialize PLA biocomposite products in an economic way, moreover, only flat-like products could be made this way.…”