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

Abstract

ResumoForam investigadas as propriedades térmicas e mecânicas de compósitos de polipropileno reciclado e virgem, reforçados com até 40% em peso de fibras de celulose (FC), bem como a morfologia da matriz polimérica. Para a obtenção dos dados, foram utilizadas as técnicas de Análise Témica Dinâmico-Mecânica (DMTA), Calorimetria Exploratória Diferencial (DSC) e Microscopia Eletrônica de Varredura (MEV). Os resultados mostraram que os compósitos de polipropileno reciclado,com percentagem de 30% FC e os compósitos de polipropileno virgem, com percentagem de 20% FC, tiveram um aumento significativo nos valores de módulo de armazenamento (E') e grau de cristalinidade (χ c ), indicando com isso uma resistência mecânica mais elevada. Já nas amostras com 40% FC, houve uma diminuição na rigidez do material. Estes resultados foram confirmados por MEV, onde observou-se a aglomeração das fibras de celulose na matriz. Não houve alteração nas temperaturas de transição vítrea (T g ) e fusão cristalina (T m ) dos compósitos produzidos. Palavras-chave: compósitos de polipropileno, fibras de celulose, compósitos pós-consumo. AbstractThe thermal and mechanical properties of composite recycled and virgin of polypropylene were investigated, reinforced with up to 40% by weight of cellulose fibers (FC), as well as the morphology of the polymer matrix. To obtain the data, techniques for Dynamic-Mechanical Thermal Analysis (DMTA) were used, Differential Scanning Calorimetry (DSC) and Scanning Electron Microscopy (SEM). The results showed that recycled polypropylene composites with a percentage of 30% FC and virgin polypropylene composites with a percentage of 20% FC had a significant increase in storage modulus values (E') and degree of crystallinity (χc), indicating a higher mechanical strength in these composites. Since the samples with 40% FC, there was a decrease in the stiffness of the material. These results were confirmed by the SEM, where noted agglomeration of the cellulose fibers in the matrix. There was no change in the glass transition temperature (Tg) and crystalline melting temperature (Tm) of the produced composite.

Investigation on influence of stamp forming parameters on formability of thermoplastic composite

“…At present, advanced glass fabric reinforced thermoplastic (GFRTP) composites are found as substitutes for metals and thermoset composites due to their better impact, corrosion-resistance and fracture toughness properties [1] . The major driver of growth for the fabric reinforced thermoplastic composite in aerospace, automotive and sporting goods industries is the increasing requirement of recyclable, lightweight, and environment friendly products [2] . The higher durability feature of thermoplastic composites made them better suitable for crash applications than the thermoset composites.…”

Mechanical characterization of HDPE reinforced with cellulose from rice husk biomass

“…Low contents of cellulose can form regions of high mechanical stress, by a not so homogeneously dispersed mixture, resulting in a decrease in elastic modulus. Higher contents of cellulose, in its turn, can result in a better distribuition of stresses, and thus greater modulus [20] . This small increase in the values of elastic modulus indicates a low interaction between the polymer and the matrix, and this can be explained by its lack of chemical affinity, since the HDPE is apolar and the cellulose is known for its polarity, as can be confirmed by FTIR.…”

Tribological behavior of cellulose nanostructured films

“…Among these materials, natural fibers are the most common [1] and have received particular attention as they have unique advantages such as biodegradability, easy disposal, low cost, and resistance. Moreover, for this reason, it is currently an attractive substitute for conventional materials developed generally by combining several types of fibers [2][3][4][5][6]. Nanostructured cellulosic elements such as cellulose nanofibrils or nanocrystals are considered excellent materials in different applications because of the properties associated with their interfiber connections between the amorphous and crystalline zones [7].…”