The influence of fiber-surface treatment on the mechanical properties of jute-polypropylene composites

Gassan, Jochen; Błędzki, Andrzej K.

doi:10.1016/s1359-835x(97)00042-0

Cited by 392 publications

(227 citation statements)

References 24 publications

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“…Considerações sobre processo, compatibilização e propriedades têm sido abordadas por inúmeros autores [10][11][12][13][14][15][16][17] . Esse amplo interesse baseia-se no fato de que a incorporação de fibras naturais em termoplásticos poliolefínicos apolares, o caráter polar da celulose requer a compatibilização do sistema através da incorporação dos chamados agentes de acoplamento ou de adesão interfacial.…”

Section: Estudos De Compatibilização De Compósitos Termoplásticos Comunclassified

Compósitos termoplásticos com madeira

et al. 2003

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Resumo: Dentre muitas fibras naturais de interesse tecnológico, o resíduo de madeira substitui com vantagens as cargas e reforços tradicionalmente empregados em compostos e compósitos poliméricos, particularmente os de origem mineral, tais como talco, CaCO 3 e fibra de vidro. A tecnologia dos chamados Wood-Plastic Composites (WPC´s) envolve conceitos de compatibilidade e processabilidade e apresenta grandes desafios tecnológicos para a formulação e estabilização da mistura devido à baixa estabilidade térmica da celulose. Muitos dos avanços tecnológicos em WPC's dependem de uma análise criteriosa das características físicas de seus componentes e das condições de processamento do sistema, particularmente aspectos relacionados a sua compatibilização. No presente trabalho são apresentados estudos sobre a reatividade do polipropileno modificado com anidrido maleico (PP-MAH) utilizado como compatibilizante em compósitos termoplásticos de polipropileno com farinha de madeira. A influência da carga celulósica e a eficiência do compatibilizante nas propriedades reológicas, térmicas, mecânicas e morfológicas do sistema foi avaliada através de medidas de rigidez, grau de cristalinidade, temperatura de cristalização e fusão cristalina levando-se em conta as características da resina, a distribuição granulométrica e o teor de umidade da farinha de madeira. Observou-se que os compósitos compatibilizados com PP-MAH apresentaram ganhos significativos de rigidez em relação aos compósitos não-modificados independentemente do tipo de farinha de madeira empregada. As propriedades térmicas do polímero mostraram-se sensíveis à distribuição granulométrica e algumas composições apresentaram tendência ao escurecimento e à elevação da temperatura de cristalização do polímero na presença do reforço celulósico. Imagens obtidas por microscopia eletrônica de varredura ilustram o molhamento da fibra celulósica pela resina termoplástica quando na presença do compatibilizante indicando a possível ocorrência de reações de esterificação na interface polímero-madeira. Palavras-Chave: Compósitos termoplástico-celulósicos, tecnologia polímero-madeira, compatibilização, reometria de torque, análise térmica. Wood-Plastic CompositesAbstract: Wood waste fibers (WWF), mostly known as wood flour, can replace mineral fillers such as talc, CaCO 3 and fiberglass in the reinforcement of thermoplastics with great advantage. Wood-plastics composites (WPC's) technology includes concepts of compatibility and processing and yet presents technical challenges in grade formulation and stabilisation of the composite system. Owing to thermal constraints in wood flour processing, commodities such as polyolefins (PP, PEAD/PEBD), styrenics (PS e HIPS) and vinyls (PVC) represent the bulk of the thermoplastics used in WPC's applications. In the present work, a brief overview of the latest developments in WPC's processing technology is discussed in the light of technical characteristics and performance of this novel class of thermoplastics composites in emerging applications...

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Section: Estudos De Compatibilização De Compósitos Termoplásticos Comunclassified

Compósitos termoplásticos com madeira

et al. 2003

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“…After modification, treatment of the fibers is necessary for composite production. Vegetable fibers are rich in cellulose, the biomaterial with the highest Young's modulus 14 . In this work, an initial pre-treatment with fungi was proposed, aiming to facilitate lignin and hemicellulose removal during chemical pulping, resulting in fibers with higher cellulose contents.…”

Section: Introductionmentioning

confidence: 99%

Polypropylene Composites Reinforced with Biodegraded Sugarcane Bagasse Fibers: Static and Dynamic Mechanical Properties

et al. 2016

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The present work aimed to study sugarcane bagasse fibers pre-treated with fungi and using NaOH/ anthraquinone (AQ) in chemical pulping processes for applications in composite materials. Bagasse was decayed with 250 mg of Ceriporiopsis subvermispora inoculum in a 20 L bioreactor. After that, samples were submitted to similar conditions of decaying without inoculum charge. Decayed and undecayed fibers were treated with NaOH 12.5 wt%, 0.15 of AQ and a 12:1 (v/w) liquor:bagasse ratio at 160°C. Then, all obtained fibers were characterized according to their chemical composition. Dried biotreated (decayed) and control (undecayed) fibers were mixed through an extruder process with polypropylene. Later, composite granulates were injected directly in mold with cavities for tensile, flexural and shear tests. Composite materials with 10 and 20 wt% fibers were submitted to static mechanical standard tests and DMA (Dynamic Mechanical Analysis) to evaluate the effect of biotreatment. Biotreatment, cook time (pulping), and fiber content contributed to improvements in the mechanical properties of the composites. The interface between fiber and matrix was increased with the biotreatment and pulping of fibers. Furthermore, DMA results also showed that fiber incorporation into PP improved the modulus, mainly for biotreated fibers/PP composites. The T g (tan δ data) from composites was dislocated at lower temperatures with respect to neat PP due to the influence of fibers on matrix.

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“…The 6 h-treated fiber showed the maximum cellulose content of 72.35%, and this value dropped to 61.26% for the 12-h treatment. Hemicellulose was more sensitive to the duration of the alkali treatment, as it was reduced from 13.02% to 0.00% after 2 h in 5% NaOH; wax contents behaved similarly (Gassan and Bledzki 1997). However, the lignin content was reduced from 4.52% (raw fiber) to 2.9% after the 12-h treatment.…”

Section: Chemical Properties Of the Fibermentioning

confidence: 93%