Title:	Valorization of cardboard waste in the production of polyurethane biocomposites: A new and environmentally friendly material for civil construction.
Authors:	FARIA, D. L. MESQUITA JUNIOR, L. LAGO, R. C. do SORIANO, J. GUIMARÃES JUNIOR, M. PIRES, N. J. Augusto Cesar da Silva Bezerra OLIVEIRA, J. E. de
Affiliation:	FEDERAL UNIVERSITY OF LAVRAS - UFLA FEDERAL UNIVERSITY OF LAVRAS - UFLA ,FEDERAL UNIVERSITY OF LAVRAS - UFLA UNIVERSITY OF CAMPINAS – UNICAMP FEDERAL CENTER OF TECHNOLOGICAL EDUCATION OF MINAS GERAIS - CEFET-MG FEDERAL CENTER OF TECHNOLOGICAL EDUCATION OF MINAS GERAIS - CEFET-MG FEDERAL CENTER OF TECHNOLOGICAL EDUCATION OF MINAS GERAIS - CEFET-MG FEDERAL UNIVERSITY OF LAVRAS - UFLA.
Date Issued:	2025
Citation:	Construction and Building Materials, v. 462, 139902, 2025.
Pages:	16 p.
Description:	Cardboard has been widely used in various applications and industry sectors, such as in civil construction as a formwork for concreting circular columns. In addition to the versatility of the product, a vast amount of waste is generated by the manufacturing process. The objective of this work was to determine the properties of green polyurethane matrix thermosetting composites reinforced with cardboard tube waste for application as thermal insulation in buildings. Preliminarily, alkaline solutions of NaOH and Ca(OH)2 were applied to the residues to remove oils and waxes that affect the polymerization of vegetable polyurethane. The cardboard tube waste was characterized according to its chemical composition, basic density, infrared spectra, atomic force microscopy, Xray diffraction, and surface SEM images. The composites were produced with 10 % (wt%) treated cardboard waste and without surface treatment to replace vegetable polyurethane through the hand lay-up method. Specimens were obtained from the composites to perform tensile tests, determine the bulk density, water absorption, and thermal conductivity, and visualize the matrix–reinforcement interface via SEM. The data indicated that surface NaOH and Ca(OH)2 treatments significantly increased the tensile strength of the composites by 76 and 187 %, respectively, compared with that of the polymer. For the composites, the use of cardboard waste significantly increased the thermal insulation, as proven by the thermal conductivity varying from 0.0607 to 0.0632 W/(m. K) and compatible with other insulating materials used in civil construction. Thus, composite polymers generated from cardboard tube waste are potential sustainable alternative construction materials.
Keywords:	Cardboard waste valorization Lignocellulosic fiber Natural fiber-reinforced composites Polymeric composites Vegetal polyurethane resin
ISSN:	0950-0618
DOI:	https://doi.org/10.1016/j.conbuildmat.2025.139902
Type of Material:	Artigo de periódico
Access:	openAccess
Appears in Collections:	Artigo em periódico indexado (CNPDIA)