Polypropylene/wood flour composites: treatments and properties

Ichazo, Miren; Albano, Carmen; González, Jeanette; Perera, R.; Candal, Marı́a

doi:10.1016/s0263-8223(01)00089-7

Cited by 408 publications

(286 citation statements)

References 11 publications

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“…In terms of cellulosic fibers, mercerization process helps to relieve some residual stresses, what makes the fibers stronger [64]. The positive role of NaOH treatment of cellulosic materials used in composites was confirmed by Ichazo et al [65] and Borysiak [25]. Similarly, composites of poly(ethylene oxide) with two polymorphic forms of cellulose nanocrystals (CNC) showed that the enhancement of tensile properties for composites with CNC II was greater than for CNC I [27].…”

Section: Mechanical and Morphological Properties Of Compositesmentioning

confidence: 92%

Thermal and mechanical properties of chitosan nanocomposites with cellulose modified in ionic liquids

Grząbka-Zasadzińska

Amietszajew

Borysiak

2017

J Therm Anal Calorim

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In this paper, ionic liquid treatment was applied to produce nanometric cellulose particles of two polymorphic forms. A complex characterization of nanofillers including wide-angle X-ray scattering, Fourier transform infrared spectroscopy, and particle size determination was performed. The evaluated ionic liquid treatment was effective in terms of nanocrystalline cellulose production, leaving chemical and supermolecular structure of the materials intact. However, nanocrystalline cellulose II was found to be more prone to ionic liquid hydrolysis leading to formation larger amount of small particles. Each nanocrystalline cellulose was subsequently mixed with a solution of chitosan, so that composite films containing 1, 3, and 5% mass/mass of nanometric filler were obtained. Reference samples of chitosan and chitosan with micrometric celluloses were also solvent casted. Thermal, mechanical, and morphological properties of films were tested and correlated with properties of filler used. The results of both, tensile tests and thermogravimetric analysis showed a significant discrepancy between composites filled with nanocrystalline cellulose I and nanocrystalline cellulose II.

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Section: Mechanical and Morphological Properties Of Compositesmentioning

confidence: 92%

Thermal and mechanical properties of chitosan nanocomposites with cellulose modified in ionic liquids

Grząbka-Zasadzińska

Amietszajew

Borysiak

2017

J Therm Anal Calorim

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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

“…Outro aspecto considerado é o comprimento das cadeias do compatibilizante que deve possuir cadeias suficientemente longas de alta massa molecular que permita a formação de emaranhamentos moleculares com a matriz polimérica na interfase através de ancoramento mecânico. Alguns autores relacionam o tratamento superficial da fibra como forma de optimização do processo de compatibilização [15][16][17][18][19][20] .…”

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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“…In the first case, the interfacial adhesion between PP and wood flour was better than in the case of MA-PP. Ichazo et al (2001) treated the wood flour with NaOH and silane and applied MA-PP as the matrix. All treatments improved the dispersion of the wood flour particles, and WPCs with silane modification combined with MA-PP addition had a lower degree of water absorption.…”

Section: Introductionmentioning

confidence: 99%

Wood polypropylene composites prepared by thermally modified fibers at two extrusion speeds: mechanical and viscoelastic properties

Askanian¹,

Verney

Commereuc³

et al. 2014

Holzforschung

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Abstract:Composites have been prepared with polypropylene (PP) as a matrix and pine flours, either thermally treated (W tr ) or not (W), as fillers resulting in wood plastic composites (WPCs). The treatment by retification at 280° mainly elevates the hydrophobicity of wood. The WPCs were fabricated with a co-rotating twin-screw extruder with the screw speeds of 500 and 1200 rpm and specimens were prepared by injection molding. Viscoelastic behavior, tensile test and Charpy impact test of W tr PC were compared with PP and WPC. W tr PC has a better dispersion and highest tensile modulus. As expected, a decrease in elongation at break and impact strength was observed for all composites. Processing at 1200 rpm improved by 60% the Young modulus of the WPC compared to 500 rpm, whereas 500 rpm was enough to obtain the highest modulus for W tr PC.

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Polypropylene/wood flour composites: treatments and properties

Cited by 408 publications

References 11 publications

Thermal and mechanical properties of chitosan nanocomposites with cellulose modified in ionic liquids

Thermal and mechanical properties of chitosan nanocomposites with cellulose modified in ionic liquids

Compósitos termoplásticos com madeira

Wood polypropylene composites prepared by thermally modified fibers at two extrusion speeds: mechanical and viscoelastic properties

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