9 documents found, page 1 of 1
Starch/PVA-based nanocomposites reinforced with bamboo nanofibrils.
Guimarães Júnior, Mário; Botaro, Vagner Roberto; Novack, Kátia Monteiro; Teixeira, Fábio Gomes; Tonoli, Gustavo Henrique DenzinThis work aimed to evaluate the effect of including different concentrations of bamboo nanofibrils on physical, mechanical, morphological and structural properties of nanocomposites from cassava starch and polyvinyl alcohol (PVA). Nanocomposites were prepared with blends of starch/PVA and nanofibrils of bamboo. Chemical pre-treatments and mechanical defibrillation were used to obtain the nanofibrils. The mixtur...
Synthesis and characterization of hydrogels from cellulose acetate byesterifica...
Senna, André Martins; Novack, Kátia Monteiro; Botaro, Vagner RobertoHydrogels were prepared from cellulose acetate with a degree substitution (DS) 2.5 dissolved indimethylformamide by esterification crosslinking with Ethylenediaminetetraacetic dianhydride (EDTAD)catalyzed by triethylamine. Subsequent conversion of the unreacted carboxyl groups to sodium carbox-ylates by the addition of aqueous NaHCO3was performed to enhance the water affinity of the gels. Theabsorbency of the p...
Caracterização anatômica da fibra de bambu (Bambusa vulgaris) visando sua utili...
Guimarães Júnior, Mário; Novack, Kátia Monteiro; Botaro, Vagner RobertoO desenvolvimento de materiais compósitos utilizando fibras vegetais como reforço é crescente e vêm conquistando novos segmentos de mercado, pois as fibras vegetais apresentam baixo custo, biodegradabilidade, menor densidade e boas propriedades mecânicas, físicas e térmicas adequadas às aplicações industriais. Este trabalho apresenta os resultados de recentes pesquisas sobre a fibra de Bambusa vulgaris realizad...
Caracterização físico-química de fibra e polpas de Bambusa vulgaris Schrad para...
Guimarães Júnior, Mário; Novack, Kátia Monteiro; Botaro, Vagner Roberto; Protásio, Thiago de Paula; Couto, Allan MottaAtualmente é crescente o interesse pelos compósitos poliméricos reforçados com fibras naturais vegetais em substituição às fibras manufaturadas. Isto se deve ao fato das fibras vegetais serem menos abrasivas, biodegradáveis, apresentar baixa densidade e excelentes propriedades mecânicas e térmicas. Várias fibras vegetais vêm sendo utilizadas nos mais variados tipos de compósitos, dentre as quais as de bambu se ...
Caracterização de polpas de bambu modificadas quimicamente visando melhorias em...
Guimarães Júnior, Mário; Novack, Kátia Monteiro; Botaro, Vagner Roberto; Protásio, Thiago de PaulaNos últimos anos, compósitos reforçados com fibras naturais têm despertado interesse devido sua baixa densidade, não abrasividade, baixo custo e biodegradabilidade. Entre as várias fibras naturais; linho, bambu, sisal, rami e juta são de particular interesse. Em todo o mundo, inúmeras pesquisas têm sido realizadas sobre o uso de fibras naturais como material de reforço visando à produção de compósitos. No entan...
Hybrid chipboard panels based on sugarcane bagasse, urea formaldehyde and melam...
Barros Filho, Roberto Monteiro de; Mendes, Lourival Marin; Novack, Kátia Monteiro; Aprelini, Leonardo Oliveira; Botaro, Vagner RobertoThe expansion of Brazilian agricultural production was very important in the last decade. A number of waste residues were produced showing an enormous potential for industrial crops and products. Sugarcane bagasse is the most important one and it has been investigated for chipboard panel’s preparation. In this sense, this work aims to develop, characterize and compare chipboard panels made with sugarcane bagass...
Bamboo pulp treated with NaOH and benzophenone tetracarboxylic dianhydride as r...
Guimarães Júnior, Mário; Novack, Kátia Monteiro; Botaro, Vagner RobertoBamboo admittedly and engineering material widely used for buildings in several countries. However, lack of good interfacial adhesion, low melting point, and poor resistance towards moisture make the use of natural fiber reinforced composites less attractive. The aim of this work was esterify the refined pulp of bamboo came from kraft industrial pulping, previously treated with sodium hydroxid and organic solve...
Adsorption of heavy metal ion from aqueous single metal solution by chemically ...
Karnitz Júnior, Osvaldo; Gurgel, Leandro Vinícius Alves; Melo, Júlio César Perin de; Botaro, Vagner Roberto; Melo, Tânia Márcia SacramentoThis work describes the preparation of new chelating materials derived from sugarcane bagasse for adsorption of heavy metal ions in aqueous solution. The first part of this report deals with the chemical modification of sugarcane bagasse with succinic anhydride. The carboxylic acid functions introduced into the material were used to anchor polyamines, which resulted in two yet unpublished modified sugarcane bag...
Chemical modification of lignocellulosic materials by irradiation with Nd-YAG p...
Botaro, Vagner Roberto; Santos, Cláudio Gouvêa dos; Arantes Júnior, Gilberto; Costa, Adilson Rodrigues daMost reports about modification of lignocellulosics are mainly based on chemical modifications such as specific reactions on hydroxyl groups of cellulose. In this work, we describe the irradiation of Whatman 5 filter paper, microcrystalline cellulose and organosolv lignin with Nd-YAG laser pulses at 1064 nm. The chemical and structural properties of the degraded products were investigated by using FTIR and UV s...