Efeito da impregnação com polímeros sobre as propriedades mecânicas do Bambu B. vulgarias

• Ano de defesa: 2017
• Autor(a) principal: Ortiz, Sandra Patricia Reyes
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal da Paraíba; Brasil; Engenharia de Materiais; Programa de Pós-Graduação em Ciência e Engenharia de Materiais; UFPB
• Palavras-chave em Português: Estireno; Metacrilato de metila; Acrilato de butila; Compressão paralela às fibras; Compressão perpendicular às fibras; Flexão; Absorção de água; Variação dimensional; Durabilidade; Styrene; Methyl methacrylate; Butyl acrylate; Parallel fiber compression; Fiber perpendicular compression; Flexure; Water absorption; Dimensional variation; Durability; CNPQ::ENGENHARIAS
• Link de acesso: https://repositorio.ufpb.br/jspui/handle/123456789/12920

Researches that addresses the process of impregnation with polymers generally refers to wood and only a few works deal with bamboo. Perhaps this is because, in the knot region, the internal structure of bamboo is very complex. The aim of this work was to present the effect of polymer impregnation on the physical-mechanical properties of B. vulgaris bamboo, practically the only bamboo species available in the State of Paraíba. Initially it was intended to reach the impregnation of long stems, but soon it was seen the difficulty of passing the polymers through the knots. In this way, the study of the impregnation of small samples of bamboo was initiated adapting to the norms ASTM 1413-99 and ASTM 143-09. In this work, the polymerization processes of the styrene (St), methyl methacrylate (MMA) and butyl acrylate (BuA) monomers were investigated in the respective homopolymers, as well as in the poly (St-co-MMA) copolymer, designated as SM, and poly (St-co-MMA-co-BuA) terpolymer, designed SMB. The kinetics of the reaction, the degree of conversion and the viscosity were studied in order to know the polymerization process before impregnations were carried out in the inner tissues of the bamboo. The specimens prepared for the mechanical tests maintained the proportions 1: 1: 4 and 1: 1: 15 in relation to the thickness: width: length. Modifications of the lignocellulosic material after infiltration of 2.5% glutaraldehyde solution (GA) and impregnation with the vacuum blends (SM and SMB) were evaluated using optical microscopy (OM) and Scanning electron microscopy (SEM), X-ray diffractometry (XRD), thermal analysis (DSC and TGA) and infrared spectroscopy (FTIR). Results have confirmed the presence of polymers within the bamboo tissues, indicating the applied methodology success. In order to evaluate the physical and mechanical properties of the impregnated test specimens, similar test specimens were always tested in the natural condition (BN) and also test specimens that were exposed to the temperature of 50ºC (BT), considered as a reference. The evaluation of the mechanical properties was carried out by means of compression test parallel of the fibers, compression test perpendicular to the fibers and the bending test, together with the respective modulus of elasticity. The samples impregnated with SM and SMB pre-infiltrated with the GA solution presented better performance than those in the natural condition, exhibiting a decrease in water absorption, dimensional variations and increasing mechanical strength and modulus of elasticity, as well as showing Visually immune to insect attack.